​A number of tiny non-stinging wasps, mites and flies cause abnormal growths to develop on the leaves, twigs or branches of oak trees. These galls can include growths that are round, spiny, flattened, elongated or star-shaped. There are hundreds of different types of galls, each of which is caused by a specific insect. Galls form in response to a chemical that the insect injects into the plant tissue. Mature females lay eggs that hatch into legless grubs. Galls form around them. Larvae feed, develop, and pupate inside these galls. Adults may emerge either the same season or may overwinter inside the gall depending on the life history of that specific insect.
       
Generally, these gall insects do not cause significant damage to their hosts, though some of the leaf galls can cause enough deformity to make a tree unsightly. Also, severe infestations of twig galls can cause twig dieback or, rarely, tree death. However, just because a twig is covered with galls does not mean it is dead. I have seen twigs that looked like a solid mass of galls leaf out in the spring. Insecticide sprays applied when galls are noticed are ineffective because damage has already occurred. Also, larvae are unaffected because of the protection afforded by the gall.  Insecticide sprays can kill emerging adult wasps and flies, but long periods of emergence and short residuals of most contact insecticides make this impractical. Stem and twig galls can be pruned if deemed to be practical and necessary. In short, this is a problem that is best ignored unless pruning is done to improve the appearance of the tree. (Ward Upham)

Many people mistake little barley (Hordeum pusillum) for a little foxtail because the foxtail and little barley seedheads are similar. However, little barley is a winter annual that thrives in the cooler spring temperatures but dies out in the summer. Foxtail, on the other hand, is a summer annual that does well in hot weather. Also, foxtail will not produce seedheads until mid- to late-summer.
 
At this point there is no control for little barley other than a glyphosate product such as Roundup. However, Roundup will kill whatever it hits and cannot be used in a lawn situation. The only preemergence herbicide that I know that is labeled for lawn situations is Surflan. Monterey Lawn and Garden also sell it under the name of Weed Impede. Surflan can only be used on warm-season grasses (bermudagrass, buffalograss, zoysiagrass) and tall fescue grown in warm-season areas. Because little barley is a winter annual, apply the preemergence herbicide in September.  (Ward Upham)

Megan Kennelly, our Horticulture Plant Pathologist, has updated her publication on brown patch.  You can find the publication at  http://tinyurl.com/zyyn29d , Following is the introduction from the publication, “Brown patch, caused by the fungus Rhizoctonia solani, is common on tall fescue lawns in Kansas during the summer. The fungus becomes highly active when conditions are moist and nighttime low temperatures are above 65o F, with dew and high humidity. In Kansas this frequently occurs in July and August, but those conditions can occur at other times. This article provides information for homeowners with tall fescue lawns.”

​We should have good fruit crops this year as long as we can avoid severe weather. Keep in mind some tips to help ensure healthy trees, vines and fruit.
 
 * Remove fruit from heavily loaded apples and peaches (if the flower buds weren’t killed by frost) to improve fruit size and prevent limbs from breaking. Apples should be spaced every 4 inches and peaches every 6 to 8. Note that is an average spacing. Two fruit can be closer together if the average is correct.
 
  * Remove sucker growth from the base of fruit trees and grape vines.
 
  * Remove water sprout growth from fruit trees. Water sprouts grow straight up.
 
  * "Comb" new growth on grape vines so these new shoots hang down for greater exposure to sunlight.
 
  * Continue disease and insect control to prevent fruit damage. (Ward Upham)

​Be on the lookout for cherry leaf spot.  This disease causes small, pinpoint dark lesions on cherry leaves. The black spots often fall out, resulting in a shot-hole appearance. Numerous lesions turn light green, then yellow, and eventually the infected leaf will drop.
 
Removing diseased leaves at the end of the season can help, but fungicide applications during the growing season are also useful.  No fungicide can be applied during harvest but captan (Hi-Yield Captan, Bonide Fruit Tree Spray, Gordon’s Liquid Fruit Tree Spray) can be applied up to harvest. If the disease is still active, an application after harvest and two weeks later is recommended. (Ward Upham)

​Many gardeners look forward to harvesting new potatoes this time of year. New potatoes are immature and should be about the size of walnuts.  Pull soil away from the base of the plants to see if the tubers are the desired size. If they are, dig entire plants and allow the skins of the exposed tubers to dry for several hours before gathering.
 
These young potatoes are very tender and prone to the skin “slipping” unless they are given a few hours to dry. Even then these immature potatoes will not store well. Red-skinned varieties are often preferred as they are the earliest to produce.  (Ward Upham)

​Some plants will bloom more profusely if the old, spent flowers are removed, a process called deadheading.  Annuals especially, focus their energy on seed production to ensure that the species survives. If you remove old flowers, the energy normally used to produce seed is now available to produce more flowers.
 
Perennials can also benefit by lengthening the blooming season. However, some gardeners enjoy the look of spent flowers of perennials such as sedum or purple coneflower. Also, the seed produced can be a good food source for birds.
 
Not all plants need to be deadheaded, including sedum 'Autumn Joy', melampodium, impatiens, most flowering vines, periwinkle (Catharanthus), and wishbone flower (Torenia).
 
Those that do increase bloom in response to deadheading include hardy geraniums, coreopsis, petunias, marigolds, snapdragons, begonias, roses, campanulas, blanket flowers, delphiniums, zinnias, sweet peas, salvia, scabiosa, annual heliotrope, geraniums (Pelargonium), and yarrow.
 
Deadheading is easily accomplished by removing spent flowers. With some plants, pinching between a thumb and finger can do this, but tough, wiry stems will require a scissors or pruning shears. (Ward Upham)

​It’s not too late to get some plants in the ground or in a container. I’ve found myself scrambling to do my own gardening this year. April’s weather was eclectic and May was jam-packed with all kinds of end-of-school events. I did manage to fill a few containers on my birthday, but my flower beds are woefully empty. I imagine I am not alone in my desire to plant something and I’ve been telling myself that it’s just a matter of time…I’ll get to it. In the meantime, I’ve been admiring the fresh, lush growth of trees, shrubs, and perennials wherever I see them.
 
Notably, I’ve seen quite a few public planting containers with annual flowers in them. This means that people are thinking about color and about gifting their presence to others who might happen to walk by. Whether they notice or not, most folks feel closer ties to their communities and pride in their public places when ornamental plants are present. Think about it…if there weren’t any plants in your public spaces—at all—what would that feel like? Might it feel just a little harsher, tougher, and less cheerful? Even “big city” folks make an effort to bring landscaping nearer their high-rise buildings. The presence of plants has been documented to increase physical and mental health for people nearby, reduce stress, contribute to healthy aging, improve quality of life, and much more.
 
So what’s keeping you from planting something? Some say that the term “gardening” isn’t cool anymore. Even though many people continue to be drawn into the love of getting their hands dirty through the desire to grow their own food, they don’t want to be called a “gardener.” I also think there is some confusion about where to buy plants. Google Trends showed me “trees for sale,” “fruit trees,” and “garden plants” as popular searches. If you were looking for a place to purchase a plant, what would you think of? For me, of course, I think of “garden center,” but do you? What about “plant store”? This is an industry-wide question and I/we welcome suggestions from folks that find the identity of plant-related activities, well, lacking. Please, do share your ideas.
 
As a young person, I remember easily confusing the terms “annual” and “perennial”. It was honestly a mess of jargon for me. Now, of course, I know loads of jargon and terminology and find it easy to forget what it felt like to not know what to call things (uncomfortable and ignorant, in the most innocent of ways—I loved gaining all of that knowledge about plants). For the record, annuals are tender plants that complete their life cycles in one year and need to be replaced yearly (or seasonally—fun!), and they often have incredibly showy floral displays. Perennials last more than one year, often many years. Technically trees and shrubs are also perennials, but we generally talk about those types of plants comparatively—woody vs. non-woody. Trees and shrubs would be called “woody plants” with above-ground structures that are visible year round and perennials are plants that return year after year, but generally die back to the ground (or above-ground portions are no longer viable) in the winter.
 
Are there aspects of gardening that overwhelm you? Truly, I want to know. I can’t tell you how much joy it brings me to share my love of gardening with other people. The term “gardener” doesn’t bother me and I’m quite proud to have a lovely garden that everyone walking through my neighborhood can enjoy. They are often amazed that I, a relatively young person with two young kids (Oh, boy, my son turns 6 this month!) manages such a beautiful space. But I do, with not nearly as much time and effort as most people think. I just wish I could make more time to work out there. However, I am content with the time I do get to garden in this season of life with little kids and I’m grateful that I still have lots to look forward to as a “gardener for life.”
 
What about you? Do you have a plan in place to plant something? You really don’t have to have a plan, just grab what catches your eye when you see it. Find a spot for it and enjoy it. (Cheryl Boyer)

​We have several reports of jumping oak galls.   The fallen galls attract attention by jumping an inch or more due to the action of the larva inside the gall.  
 
Jumping oak galls are caused by a very small, stingless wasp that lays eggs on developing oak leaf buds early in the spring.  The larva that hatches from the egg will start to feed and juices from the saliva will cause the gall to form.  The larva will feed inside the gall which offers a measure of protection.  The galls are quite small; about the size of a pinhead.  The gall eventually drops out of the leaf and falls to the ground.  The galls will then jump due to movement of the larva inside the gall.  This helps the insect move into the litter under the tree or into cracks in the soil where the insect will eventually pupate and overwinter.  The mature wasp will chew its way out of the gall the next spring to start the cycle over again.
 
White oaks and members of the white oak family can be affected.   Though heavy infestations can cause leaves to brown (or turn black), curl and possibly drop, otherwise healthy trees are not appreciably harmed.  Even if it were more serious, it is too late to treat by the time symptoms are seen.  Often natural controls prevent damage in subsequent years.  Keep trees healthy by watering during dry weather.  (Ward Upham)

Overwintering females emerge in late April and lay a cluster of bright, yellow eggs on recently emerged potato plants. Larvae mature in about 3 weeks and pupate in the soil. After another 10 days, adult beetles emerge, mate and lay more eggs.
 
Both larvae and adults of this insect feed on potato (as well as tomato, eggplant, and pepper), causing extensive loss of foliage and reducing yields. Control strategies are varied and include:
 
- Hand picking: Useful for small gardens where plants can be checked a couple of times a week. Dropping beetles and larvae in a container of soapy water will lead to their demise.
 
- Floating row cover: This material can be placed over the planting and act as a physical barrier to the insects. Be sure to seal the edges. It is sometimes suggested to leave the floating row cover in place during the growing season because potatoes do not need to be pollinated to produce tubers. Often, this is not practical because it interferes with weed control.
 
- Insecticides: A number of products are registered including spinosad (Fertilome Borer, Bagworm, Leafminer and Tent Caterpillar Spray and Bonide Colorado Potato Beetle Beater Concentrate), permethrin (numerous trade names) and lambda- or gamma-cyhalothrin (Bonide Beetle Killer, Spectracide Triazicide). (Ward Upham)
 
Contributors: Cheryl Boyer, Nursery Crops and Garden Center Extension Specialist; Ward Upham, Extension Associate

The wet weather we have seen in some areas has caused perfect conditions for the formation of brown rot on stone fruits such as peaches and plums. Affected fruit develop a gray to brown, fuzzy growth on the fruit, itself, which may rot in as little as a day or two. It is best to start treating fruit about a month before harvest but spraying is still helpful even if we are within that one month period. Fruit that shows symptoms cannot be saved but should be destroyed to prevent further spread.
 
Use Captan or myclobutanil (Immunox) for control. Many fruit tree sprays contain Captan but check the label to be certain. Apply Captan or Immunox every 7 to 14 days.  Both products can be applied up to the day of harvest.  Note that though Immunox is labeled for fruit but Immunox Plus is not. (Ward Upham)

Modern annual flowers have been bred to flower early and over a long period of time. They are not as easily thrown off flowering by high nitrogen levels as vegetables are. As a matter of fact, providing nitrogen through the growing season (sidedressing) can help maintain an effective flower display for warm-season flowers.
 
Apply a high nitrogen sidedressing four to six weeks after flowers have been set out. Additional fertilizations every three to four weeks can be helpful during a rainy summer, or if flower beds are irrigated. Common sources of nitrogen-only fertilizers include nitrate of soda, urea, and ammonium sulfate. Blood meal is an organic fertilizer that contains primarily, but not exclusively, nitrogen. Use only one of the listed fertilizers and apply at the rate given below.
 
Nitrate of soda (16-0-0): Apply 1/3 pound (.75 cup) fertilizer per 100 square feet.
Blood Meal (12-1.5-.6): Apply 7 ounces (7/8 cup) fertilizer per 100 square feet.
​Urea (46-0-0): Apply 2 ounces (1/4 cup) fertilizer per 100 square feet.
Ammonium Sulfate (21-0-0): Apply 4 ounces (½ cup) fertilizer per 100 square feet.
 
If you cannot find the above materials, you can use a lawn fertilizer that is about 30 percent nitrogen (nitrogen is the first number in the set of three) and apply it at the rate of 3 ounces (3/8 cup) per 100 square feet. Do not use a fertilizer that contains a weed killer or weed preventer.  (Ward Upham)

It is important to leave spring-flowering bulb foliage in place until it “ripens” or becomes brown.  The energy produced by the leaves after flowering is transferred to the bulb so that it can flower the following year.
 
The ripening  process should be near completion about now for tulips, daffodils and various other spring- flowering bulbs.  Use clippers, scissors or even a mower to remove dead foliage.  Also, try to map out where the bulbs are planted as there will be no foliage to make the location next fall when it is time to fertilize.  (Ward Upham)

Rose rosette is a serious problem in Kansas on wild roses (Rosa multiflora) in pastures and hedges. It is also found in domestic rose plantings.
 
Infection is thought to start with rapid elongation of a new shoot. The rapid shoot growth may continue for several weeks to a length of two to three feet. Following shoot elongation, a witches' broom or clustering of small branches occurs. The stems develop excessive thorniness and produce small, deformed leaves with a reddish-purple pigmentation. Stems and petioles of Rosa multiflora plants may have reddish blotches or streaks.
 
Rose plants infected with the rose rosette virus die rapidly, usually within one to two years. Rose rosette is caused by a Emaravirus species.  Transmission of the disease has been shown experimentally through grafting and is also thought to be spread by mites. Though KnockOut roses are resistant to many diseases, they are susceptible to this one.
 
There is no effective control measure for infected plants. In garden settings, infected plants should be removed and destroyed, including roots. Any roots that remain after plant removal may produce infected shoots which can harbor the disease. If possible, eliminate all multiflora rose plants from the vicinity as they are extremely susceptible and will act as a carrier. Multiflora rose is the wild rose often seen growing in ditches and pastures.
 
Since the disease can be transmitted by pruning shears, disinfect the shears when moving from one plant to another by using rubbing alcohol or a disinfectant such as Lysol. (Ward Upham)

The European fruit lecanium scale (Parthenolecanium cornii) is quite noticeable on bald cypress (Taxodium distichum) twigs and branches. The damage associated with this scale, which depends on the extensiveness of the infestation, includes plant stunting and wilting. The European fruit lecanium scale is a soft scale, so honeydew (a sticky, clear liquid) will be produced during feeding. The honeydew serves as a substrate for black sooty mold and attracts ants. In addition, honeydew can drip onto vehicles parked underneath infested trees leaving unsightly residue.
 
The scales are dark brown, 1/8 to 1/4 inches in diamete. Some scales may have white markings on the body. European fruit lecanium scale overwinters as an immature on twigs and branches with maturing occurring in spring. In May and June, females lay many eggs underneath their bodies. In June eggs hatch into small tan-colored crawlers. The duration of an egg hatch can last several days depending on the temperature. Crawlers migrate to leaf undersides and subsequently feed on plant fluids until late summer. At that point, the crawlers migrate back onto twigs and branches to complete their development the following spring. There is one generation per year in Kansas.
 
Management of European fruit lecanium scale primarily involves timely applications of insecticides.  Applications should be made when crawlers are present because the crawlers are most vulnerable life stage to insecticide sprays. Mature scales possess a shell-like covering that protects them from exposure to insecticides. Repeat applications will be required as the eggs do not all hatch simultaneously but may hatch over a three to four-week period. The most appropriate time to apply insecticides is in late June to early July when the crawlers are feeding on leaves; thus enhancing their exposure to any spray residues. There are a number of insecticides, with contact activity that are effective in suppressing populations of the European fruit lecanium scale. However, many have broad-spectrum activity and will kill many natural enemies including: parasitoids and predators. In fact, most outbreaks of scale insects are caused by the indiscriminate use of pesticides (insecticides and miticides). Therefore, always read the label and exercise caution when applying any pesticide. In the winter, dormant oils can be applied to kill overwintering scales by means of suffocation.
 
I need to acknowledge Jeff Otto of Wichita, KS for bringing to my attention that European fruit lecanium scale was active. I have also observed infestations in Manhattan, KS.  (Raymond Cloyd)

As with many areas in Kansas, Sedgwick County has seen a high level of oak vein pocket gall this year. Matthew McKernan, our Sedgwick County Horticulture Agent and Dr. Raymond Cloyd, our Horticulture Extension Entomologist, have put together a two page fact sheet discussing the problem. Excellent photos and informative text make this a timely and valuable resource for those who need more information on this subject. You can find the publication at: http://www.hfrr.k-state.edu/doc/hort-tips/Oak-Vein-Pocket-Gall.pdf
(Ward Upham)

Ticks are very active throughout the state, and have been for the past month. The most commonly reported
species has been the American dog tick, Dermacentor variabilis.

The cool, humid weather over the past month has provided great conditions for tick development.  These annoying, and potentially dangerous parasites have even been encountered in corn fields, which is unusual as they typically develop in more undisturbed areas of grasses, weeds, and other overgrown vegetation. But, they are very good at finding hosts and getting the blood meal they require for development and reproduction. For more information on ticks in Kansas, please visit: https://www.vet.k-state.edu/vhc/docs/ticks-in-kansas.pdf.  (Jeff Whitworth and Holly Schwarting)

Many bagworms have hatched and have come out of the mother's bag but we are still a bit early to treat as we may miss those that are late to emerge.  The latter half of June is a good target to treat for these insects. However, make sure you have living bagworms as sometimes natural predators and parasites provide good levels of control. Look for a miniature version of the mature bagworm. They are still tiny and are about the size of the lead point on a pencil.
 
Insecticides commonly used for controlling bagworms include spinosad (Conserve; Fertilome Borer, Bagworm, Leafminer & Tent Caterpillar Spray; Captain Jack’s Dead Bug Brew, Bonide Caterpillar Killer), Bacillus thuringiensis (Dipel, Thuricide), acephate (Acephate, Orthene, Bonide Systemic Insect Control), cyfluthrin (Tempo, Bayer Vegetable & Garden Insect Spray) and permethrin (numerous trade names). Products containing Bacillus thuringiensis (BT) are only effective when used against bagworm larvae while they are still small. Note that spinosad and BT are both organic but spinosad is a more effective product, especially on larger larvae.
 
Thorough coverage is vital for good control. Most failures are due to the spray not penetrating deep enough in the tree rather than the insecticide not working. (Ward Upham)

Some areas of Kansas have had saturated or near-saturated soils for several weeks now. Gardeners are likely to assume that watering won’t be needed for quite some time now as soil moisture levels are very high. Actually, watering may be needed much sooner than you expect. Excessive rain can drive oxygen out of the soil and literally drown roots.
Therefore, as we enter hotter, drier weather, the plants with damaged root systems may be very susceptible to a lack of water. Don’t forget to check your plants for signs of wilting or leaf scorching and water as needed.
 
If irrigation is called for, water deeply and infrequently. Usually once per week is sufficient depending on the weather. Soil should be moist but not waterlogged. (Ward Upham)
 
Contributors: Raymond Cloyd, Extension Entomologist; Holly Schwarting, Entomology; Ward Upham, Extension Associate; Jeff Whitworth, Entomology

The Johnson County Extension Master Gardeners Public Garden Tour will be held May 20 and 21. Six private gardens will be open to the public. Each garden is unique and has something of interest for gardeners. For more information visit www.johnson.k-state.edu for more information

Sweet corn is one of those crops that is only "good" for a few days. If you want longer periods of production, consider staggering the planting. In other words, plant a small block, wait a period of time, and then plant the next block. Though it is tempting to follow a calendar schedule, such as planting a small block every week, it is better to use crop development as a trigger. If you plant on a calendar schedule, you may have noticed that later plantings often catch up with earlier ones. Instead, plant the next block of sweet corn when the previous one is one-half to one inch tall. (Ward Upham)

Some areas of Kansas have avoided late freezes resulting in a heavy fruit crop this year. At first glance, this might seem to be a good thing. But too many fruit can cause problems that should be alleviated with thinning. For example, a heavy fruit crop can interfere with fruit bud development this summer. This can result in a small to no crop next year. This problem most often appears with apples. Thus, thinning helps ensure that good crops are produced each year.

The second benefit of thinning is to promote larger fruit on this year’s crop. Fruit trees are limited in how many fruit they can mature. Too many fruit and fruit size goes down.

A third problem often caused by too many fruit is limb damage. Sometimes the weight of a maturing fruit crop can literally break branches. Thinning will help limit weight and preserve branches.

So how much thinning should we do? Thinning recommendations vary with the type of tree.

Guidelines for fruit spacing are as follows:
Apples and pears: 4 to 6 inches apart;
Peaches: 6 to 8 inches apart;
Plums and prunes: 4 to 5 inches apart;
Apricots: 2 to 4 inches between fruit.

​These are averages and so you may have several fruit clustered closer than this distance. As long as the average on the branch is close to the recommended spacing, the fruit should size well. Cherries are not thinned and can produce a full fruit load. (Ward Upham)

This is the time of year we normally start seeing damage from cabbage worms. The imported cabbage worm is usually the first cabbage worm species to appear and is a fuzzy, elongated green worm. Larvae come from eggs laid by the white butterfly often seen flitting around the plants.

Early control is essential to reduce injury. BT (Bacillus thuringiensis) and spinosad (Borer, Bagworm, Leafminer and Tent Caterpillar Spray; Captain Jack's Dead Bug Brew) are effective organic products that are labeled for this pest. BT can be found in Dipel, Thuricide and other similar materials. Direct sunlight deactivates BT quickly so it is helpful to spray late in the day or on a cloudy day.

​Conventional insecticides such as carbaryl (Sevin), malathion and methoxychlor are also effective but will kill natural enemies of these pests. Be sure to hit the underside of leaves where insects feed. Note that hitting the underside of leaves is easier when using a dust applied with a duster than when using a liquid spray. (Ward Upham)

This insect has been skeletonizing rose leaves in the Kansas City area. This is not a caterpillar but is the larva of a sawfly. Close examination of this small (½ inch) larva will reveal very fine, hairlike spines in clusters.

Young larvae will remove the green layer of a leaf leaving behind a clear material. As the larvae mature, they make holes in the leaf and eventually may consume all of the leaf but the major veins.

​Since these insects are not caterpillars (larvae of moths or butterflies), BT, found in Dipel and Thuricide will not be an effective treatment. However, a strong jet of water will dislodge the slugs and make it difficult for them to return to the plant. Other effective treatments include insecticidal soap, horticultural oils, spinosad (Fertilome Borer Bagworm, Leafminer and Tent Caterpillar Spray or Captain Jack’s Deadbug Brew) and permethrin (various trade names). (Ward Upham)

​Both the adults and the larvae of the ladybird beetle are beneficial and do not feed on plants but rather on other insects including aphids, mealybugs, whiteflies, scale insects and the eggs of various other insects. So if you see these insects, do not spray. The larval form looks like a very small alligator-shaped insect. Larvae are covered with spines, about 3/8-inch long, and black with orange markings. (Ward Upham)

Like last year, we are seeing a high number of oak galls this year, especially vein pocket gall on pin oak leaves. Vein pocket gall causes abnormal swelling of the leaf near the veins.

We also saw an outbreak of oak leaf itch mites last year. This mite feeds on the larvae of the midge fly that actually causes certain types of oak leaf galls. Though the marginal leaf gall is more commonly associated with oak leaf itch mite, the mite can also feed on the larvae in vein pocket galls. However, a large number of vein pocket galls do not necessarily mean we will have an outbreak of oak leaf itch mite like we had last year. This will be a “wait and see” situation.

Actually, there are hundreds of different types of galls, each of which is caused by a specific insect or mite. Insects that can cause different galls on oaks include tiny, nonstinging wasps and flies which cause abnormal growths to develop on the leaves, twigs or branches of oak trees. The galls caused by mites can include growths that are round, spiny, flattened, elongated or star-shaped.

Galls form in response to a chemical that the insect or mite injects into the plant tissue. Eggs laid by a mature female hatch into legless grubs around which the gall forms. The larvae feed, develop, and pupate inside these galls. The adults may emerge either the same season or may overwinter inside the gall depending on the life history of that specific insect.

Generally, these gall insects do not cause significant damage to their hosts, though some of the leaf galls can cause enough deformity to make a tree unsightly. Also, severe infestations of twig galls can cause twig dieback or, rarely, tree death. However, just because a twig is covered with galls does not mean it is dead. I have seen twigs that looked like a solid mass of galls leaf out in the spring.

Insecticide sprays applied when galls are noticed are ineffective because damage has already occurred. Also, larvae are unaffected because of the protection afforded by the gall. Insecticide sprays can kill emerging adult wasps and flies, but long emergence periods and short residuals of most contact insecticides make this impractical. Stem and twig galls can be pruned if this is deemed to be practical and necessary. Fortunately, natural predators and parasites usually bring these insects under control given a year or two. Therefore, the best option is usually to do nothing.

​What about the itch mites? More bad news. We have found nothing can effectively kill or repel these mites. The only means of defense is to avoid contact. (Ward Upham)

It is often helpful to set many houseplants outside for the summer so they can recover from the low light levels endured during the winter months. As soon as night temperatures stay consistently above 55 degrees F, houseplants can be moved to their summer home. Choose a spot that has dappled shade, is protected from the wind and is close to water. A porch or a spot that receives shade from trees or buildings will work well. Putting houseplants in full sun will cause the leaves to photooxidize or sunburn because the leaves have become adapted to low light levels inside the house. Where possible, sink the pots into the ground to help moderate root temperatures and reduce watering frequency.

​If you have a number of plants, dig a trench 6 to 8 inches deep (or deeper if you have larger pots) and long enough to accommodate all of your plants without crowding. Place peat moss under and around the pots. Peat moss holds water, helps keep the pots cool and reduces evaporation from clay pots. About every two weeks, rotate the pots a quarter turn to break off any roots that have penetrated the peat moss surrounding the pot and to equalize the light received on all sides of the pot. Water as needed. If the potting soil is dry a half-inch deep in the pot, it is time to water. (Ward Upham)

Rabbits in gardens are a perennial problem because of the wide variety of plants they can feed on. This time of year, they gravitate to young vegetables and flowers. But there are some vegetables that are rarely bothered including potatoes, tomatoes, corn, squash, cucumbers, and some peppers. The question is how do you protect other, more susceptible plants? Fencing provides a quick and effective control method. The fence does not need to be tall; 2 feet is sufficient for cottontails. But the mesh must be sufficiently fine (1 inch or less) so young rabbits will not be able to go through it. Support for the fence can be supplied by a number of products, but electric fence posts work well.

Often fencing is not an acceptable choice because it affects the attractiveness of the garden. Other ways to control rabbits including repellents, trapping and shooting. Repellents are often suggested for control but often do not last long and require frequent reapplication. Also, many are poisonous and cannot be used on plants or plant parts destined for human consumption. Live traps can be used to collect and move the rabbits to a rural area several miles from where they were trapped. A number of baits can be used to entice the rabbit to enter the trap including a tightly rolled cabbage leaf held together with a toothpick. However, rabbits often avoid baits if other attractive food is available.

Another possibility is to use a motion-activated sprinkler. These are attached to a garden hose and release a short burst of water when motion is detected. Contech, Orbit and Havahart are suppliers and each is advertised as protecting up to at least 1,000 square feet. Shooting is another possibility when it is safe and legal to do so. (Ward Upham)
​
Contributors: Ward Upham, Extension Associate

Many people mistake little barley (Hordeum pusillum) for a little foxtail because the foxtail and little barley seedheads are similar. However, little barley is a winter annual that thrives in the cooler spring temperatures but dies out in the summer. Foxtail, on the other hand, is a summer annual that does well in hot weather. Also, foxtail will not produce seedheads until mid- to late-summer.

At this point there is no control for little barley other than a glyphosate product such as Roundup. However, Roundup will kill whatever it hits and cannot be used in a lawn situation. The only preemergence herbicide that I know is labeled for lawn situations is Surflan. Monterey Lawn and Garden also sell it under the name of Weed Impede. Surflan can only be used on warm-season grasses (bermudagrass, buffalograss, zoysiagrass) and tall fescue grown in warm-season areas. Because little barley is a winter annual, apply the preemergence herbicide in September. (Ward Upham)

Modern annual flowers have been bred to flower early and over a long period of time. They are not as easily thrown off flowering by high nitrogen levels as vegetables are. As a matter of fact, providing nitrogen through the growing season (sidedressing) can help maintain an effective flower display for warm-season flowers.

Apply a high nitrogen sidedressing four to six weeks after flowers have been set out. Additional fertilizations every three to four weeks can be helpful during a rainy summer, or if flower beds are irrigated. Common sources of nitrogen-only fertilizers include nitrate of soda, urea, and ammonium sulfate. Blood meal is an organic fertilizer that contains primarily, but not exclusively, nitrogen. Use only one of the listed fertilizers and apply at the rate given below.

If you cannot find the above materials, you can use a lawn fertilizer that is about 30 percent nitrogen (nitrogen is the first number in the set of three) and apply it at the rate of 3 ounces (3/8cup) per 100 square feet. Do not use a fertilizer that contains a weed killer or weed preventer. (Ward Upham)

The symptoms of iris leaf scorch are distinctive in that the leaves burn back from the tips and turn a tannish to brownish color. The center leaves of the fan are affected first. Leaf scorch differs from iris leaf spot in that the color is uniform rather than being concentrated in spots that eventually may coalesce. However, both conditions may be present at the same time.

Another distinctive symptom is the loss of roots on affected plants. Surprisingly, rhizomes are not affected. Though iris leaf scorch may occur at any time during the growing season, it is most common in early summer, and we are seeing a significant amount of it now. Fortunately, the disease does not seem to spread easily. Completely healthy plants are often right next to scorched ones.

So, what do we do about it? There was a study done a number of years ago that identified the causal organism as a mycoplasma and showed that subjecting rhizomes from scorched plants to 104 degrees F for 3 to 4 days cured the problem. However, I can’t locate a copy of the study, so I am hesitant to recommend it without reservation. Another recommendation I have seen is to give the rhizomes the “hot asphalt treatment.” This consists of digging the rhizomes and placing them on asphalt in the sun to let them cure for a week. Really, I’m not making this up. A third option suggested by a University of Nebraska publication is to lift affected plants and store them in a dry, cool place until replanting in early August. This is one of those situations where you must choose which option is the most appealing, and run with it. (Ward Upham)

One of the most important clues in determining the health of your trees is the amount of new growth that tree produces. A healthy tree should have a minimum of 4 to 6 inches of new growth each year. Check branches with the tips in the open and not shaded by the tree itself. Anything less than 4 inches on the majority of branches suggests the tree is under a great deal of stress.

So, how do you tell where the new growth stops? Look for a color change in the stem. New growth is often greener than that from the previous year. There is also often an area of what looks like compressed growth where growth transitions from one year to the next. Lastly, look at leaf attachment. Leaves are only produced on current seasons’ growth. Therefore, new growth stops where leaves are no longer attached directly to the twig but to side branches. However, pay attention as leaves may be appear to be attached directly to last year’s growth but are actually borne on short spurs. If you look closely, you can tell the difference.

All this clue tells you is whether a tree is under stress or not. It does not tell you what is causing poor growth. This year, the most common cause by far is environmental stress caused by the warm, dry winter of 2011-2012 and the drought and hot summer temperatures in 2011 and 2012. Also, this last winter was cold and very windy causing a great deal of winter damage.

Stress is cumulative. In other words, trees may not have completely recovered from stressful conditions that occurred several years ago. The accumulating stress may have damaged root systems. In some cases, root systems were damaged enough that those trees may struggle as we enter summer. Though the roots were able to keep up with moisture demands during the cooler spring weather, they may not be able to as temperatures rise. Such trees may suddenly collapse and die or slough off branches they can no longer support. If possible, water to a depth of 12 inches every couple of weeks we do not receive rain in order to avoid further stress. (Ward Upham)

Although carpenter bees look much like bumblebees, they are easy to identify if you know what to look for. Bumblebees have hairy abdomens that are usually yellow and black. Carpenter bees’ abdomens are shiny blue-black. Carpenter bees are solitary (do not form colonies) and are nonaggressive unless provoked. Only the female possesses a stinger. The male may act aggressive but is harmless.

Carpenter bees get their name from the ability of the female to bore into wood. Holes are about a half-inch in diameter and may be 6 inches deep. The female then builds six to eight cells off the main tunnel and lays an egg in each. Developing larvae feed off of "bee bread" (pollen and nectar) regurgitated by the female bee. Larvae become adults by late August and September, but do not emerge until the following spring.

Individual holes may not cause much damage, but cumulative effects of numbers of bees can weaken structures. Painting wood surfaces can make them less attractive to bees. Stains seem to have little effect. Insecticides, such as Sevin, can be used to treat openings. Sprays and dusts are both effective but sprays may only last for 1 to 2 weeks and require retreatment. Dusts are most easily applied with a puffer duster. It is best to treat near sundown when the bees have returned to their tunnel. (Ward Upham)

This insect has been skeletonizing rose leaves in the Kansas City area. This is not a caterpillar but is the larva of a sawfly. Close examination of this small (½ inch) larva will reveal very fine, hair-like spines in clusters.

Young larvae will remove the green layer of a leaf leaving behind a clear material. As the larvae mature, they make holes in the leaf and eventually may consume all of the leaf but the major veins.

Since these insects are not caterpillars (larvae of moths or butterflies), BT, found in Dipel and Thuricide will not be an effective treatment. However, a strong jet of water will dislodge the slugs and make it difficult for them to return to the plant. Other effective treatments include insecticidal soap, horticultural oils, spinosad (Fertilome Borer Bagworm, Leafminer and TentCaterpillar Spray or Captain Jack’s Deadbug Brew) and permethrin (various trade names). (Ward Upham)

We are seeing a high number of oak galls this year, especially vein pocket gall on pin oak leaves.Vein pocket gall causes abnormal swelling of the leaf near the veins. Actually, there are hundreds of different types of galls, each of which is caused by a specific insect. Insects that can cause different galls on oaks include tiny, non-stinging wasps and flies which cause abnormal growths to develop on the leaves, twigs or branches of oak trees. There are even some mites that can cause galls. These galls can include growths that are round, spiny, flattened, elongated or star-shaped. Galls form in response to a chemical that the insect or mite injects into the plant tissue. Eggs laid by a mature female hatch into legless grubs around which the gall forms. The larvae feed, develop, and pupate inside these galls. The adults may emerge either the same season or may overwinter inside the gall depending on the life history of that specific insect.

Generally, these gall insects do not cause significant damage to their hosts, though some of the leaf galls can cause enough deformity to make a tree unsightly. Also, severe infestations of twig galls can cause twig dieback or, rarely, tree death. However, just because a twig is covered with galls does not mean it is dead. I have seen twigs that looked like a solid mass of galls leaf out in the spring.

Insecticide sprays applied when galls are noticed are ineffective because damage has already occurred. Also, larvae are unaffected because of the protection afforded by the gall. Insecticide sprays can kill emerging adult wasps and flies, but long emergence periods and short residuals of most contact insecticides make this impractical. Stem and twig galls can be pruned if this is deemed to be practical and necessary. Fortunately, natural predators and parasites usually bring these insects under control given a year or two. Therefore, the best option is usually to do nothing. (Ward Upham)