Category: Core Aeration

Power Raking and Core-Aeration

8/28/2017

September is the optimum time to power rake or core-aerate tall fescue and Kentucky bluegrass lawns. These grasses should be coming out of their summer doldrums and beginning to grow more vigorously. This is a good time to consider what we are trying to accomplish with these practices.

Power raking is primarily a thatch control operation. It can be excessively damaging to the turf if not done carefully. For lawns with one-half inch of thatch or less, I don’t recommend power raking but rather core aeration. For those who are unsure what thatch is, it is a springy layer of light-brown organic matter that resembles peat moss and is located above the soil but below the grass foliage. Power raking pulls up an incredible amount of material that then must be dealt with by composting or discarding.

Core-aeration is a much better practice for most lawns. By removing cores of soil, core-aeration relieves compaction, hastens thatch decomposition, and improves water, nutrient, and oxygen movement into the soil profile. This operation should be performed when the soil is just moist enough so that it crumbles easily when worked between the fingers. Enough passes should be made so that the holes are spaced about 2 to 3 inches apart. Ideally, the holes should penetrate 2.5 to 3 inches deep. The cores can be left on the lawn to fall apart naturally (a process that usually takes two or three weeks, depending on soil-type), or they can be broken up with a power rake set just low enough to nick the cores, and then dragged with a section of chain-link fence or a steel doormat. The intermingling of soil and thatch is beneficial to the lawn. (Ward Upham)

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Horticulture Newsletter 2016, No. 35

8/30/2016

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Video of the Week:
Pears, Tips on Harvesting

Turfgrass:
Fall Lawn Seeding Tips

The keys to successful lawn seeding are proper rates, even dispersal, good seed to soil contact, and proper watering. Evenness is best achieved by carefully calibrating the seeder or by adjusting the seeder to a low setting and making several passes to ensure even distribution. Seeding a little on the heavy side with close overlapping is better than missing areas altogether, especially for the bunch-type tall fescue, which does not spread. Multiple seeder passes in opposite directions should help avoid this problem.

A more serious error in seeding is using the improper rate. For tall fescue, aim for 6 to 8 pounds of seed per 1,000 square feet for new areas and about half as much for overseeding or seeding areas in the shade. Using too much seed results in a lawn more prone to disease and damage from stress. The best way to avoid such a mistake is to determine the square footage of the yard first, and then calculate the amount of seed. Using too little seed can also be detrimental and result in clumpy turf that is not as visually pleasing.

Establishing good seed to soil contact is essential for good germination rates. Slit seeders achieve good contact at the time of seeding by dropping seed directly behind the blade that slices a furrow into the soil. Packing wheels then follow to close the furrow. The same result can be accomplished by using a verticut before broadcasting the seed, and then verticutting a second time.

Core aerators can also be used to seed grass. Go over an area at least three times in different directions, and then broadcast the seed. Germination will occur in the aeration holes. Because those holes stay moister than a traditional seedbed, this method requires less watering. If seeding worked soil, use light hand raking to mix the seed into the soil. A leaf rake often works better than a garden rake because it mixes seed more shallowly.

Water newly planted areas lightly, but often. Keep soil constantly moist but not waterlogged. During hot days, a new lawn may need to be watered three times a day. If watered less, germination will be slowed. Cool, calm days may require watering only every couple of days. As the grass plants come up, gradually decrease watering to once a week if there is no rain. Let the plants tell you when to water. If you can push the blades down and they don't spring back up quickly, the lawn needs water. Once seed sprouts, try to minimize how much traffic (foot, mower, dog, etc.) seeded areas receive until the seedlings are a little more robust and ready to be mowed. Begin mowing once seedlings reach 3 to 4 inches tall. (Ward Upham)

Overseeding a Lawn

Tall fescue lawns that have become thin over the summer can be thickened up by overseeding during September. Start by mowing the grass short (1 to 1.5 inches) and removing the clippings. This will make it easier to achieve good seed-soil contact and increase the amount of light that will reach the young seedlings.

Good seed-soil contact is vital if the overseeding is to be successful. Excess thatch can prevent seed from reaching the soil and germinating. Normally we want 1/4 inch of thatch or less when overseeding. If the thatch layer is 3/4 inch or more, it is usually easiest to use a sod cutter to remove it and start over with a new lawn. A power rake can be used to reduce a thatch layer that is less than 3/4 inch but more than a quarter inch.

Once thatch is under control, the soil should be prepared for the seed. This can be done in various ways. For small spots, a hand rake can be used to roughen up the soil before the seed is applied.

A verticut machine has solid vertical blades that can be set to cut furrows in the soil. It is best to go two different directions with the machine. A slit seeder is a verticut machine with a seed hopper added so the soil prep and seeding operation are combined. Another option is to use a core aerator.

The core aerator will punch holes in the soil and deposit the soil cores on the surface of the ground. Each hole produces an excellent environment for seed germination and growth. Make three to four passes with the core aerator to ensure enough holes for the seed. Using a core aerator has the additional benefit of reducing the amount of watering needed to get the seed germinated and growing. Aeration also increases the water infiltration rate, decreases compaction, and increases the amount of oxygen in the soil.

If the three methods, I prefer the slit seeder for obtaining good seed/soil contact. However, if watering is difficult, core aeration may be a better option. Regardless of method used, fertilize should be applied at the rate suggested by a soil test, or a starter fertilizer should be used at the rate suggested on the bag. (Ward Upham)

Power Raking and Core-Aeration

September is the optimum time to power rake or core-aerate tall fescue and Kentucky bluegrass lawns. These grasses should be coming out of their summer doldrums and beginning to grow more vigorously. This is a good time to consider what we are trying to accomplish with these practices.

Power raking is primarily a thatch control operation. It can be excessively damaging to the turf if not done carefully. For lawns with one-half inch of thatch or less, I don’t recommend power raking but rather core aeration. For those who are unsure what thatch is, it is a springy layer of light-brown organic matter that resembles peat moss and is located above the soil but below the grass foliage. Power raking pulls up an incredible amount of material that then must be dealt with by composting or discarding.

Core-aeration is a much better practice for most lawns. By removing cores of soil, core-aeration relieves compaction, hastens thatch decomposition, and improves water, nutrient, and oxygen movement into the soil profile. This operation should be performed when the soil is just moist enough so that it crumbles easily when worked between the fingers. Enough passes should be made so that the holes are spaced about 2 to 3 inches apart. Ideally, the holes should penetrate 2.5 to 3 inches deep. The cores can be left on the lawn to decompose naturally (a process that usually takes two or three weeks, depending on soil-type), or they can be broken up with a power rake set just low enough to nick the cores, and then dragged with a section of chain-link fence or a steel doormat. The intermingling of soil and thatch is beneficial to the lawn. (Ward Upham)

Flowers:
Dividing Peonies

Peonies are a favorite perennial of gardeners because of their beauty and low maintenance. In Kansas, peonies provide a beautiful display of flowers each spring before Memorial Day. Though peonies can be left in place indefinitely, many gardeners wish to increase their plantings and use a process known as division to accomplish this. Keep in mind, however, that peonies often take about three years to return to full bloom and size after division.

Fall is the traditional time to divide these plants. Peonies are essentially dormant by mid-August even though the foliage is still green. The first step in division is to remove the foliage. Then dig out the entire plant. Shake and wash off as much soil as possible so that the pink buds or "eyes" are visible. Peony roots are tough, and a sharp knife is needed to cut the roots into separate pieces. Make sure each division has three to four buds. Make sure the location chosen for planting receives at least a half-day of full sun. However, the more sun, the better. Space the plants so that there is at least 2 feet between dwarf types and 4 feet between the standard types.

Follow the same rules for planting these divisions as you do for new plants. Make sure the pink buds are about 1 inch below the soil surface. If they are set more than 2 inches deep, flowering may be delayed or completely prevented. As you set the plants, firm soil often as it is added around the plant. If the soil is not firmed, it can settle and pull the plant down with it. Water in well after planting and water as necessary through the fall and winter to keep the soil moist.

It is often a good idea to add mulch to the new planting to protect it from heaving. The alternate freezing and thawing that commonly occurs during Kansas winters can "heave" weakly rooted plants out of the ground. Add a mulch of straw, leaves, compost or other material after the soil freezes. Remember, it is not the cold that harms these plants but the alternate freezing and thawing of the soil. (Ward Upham)

Miscellaneous:
Twig Dieback on Oak

Recently we have seen twig dieback on pin and other oaks caused by a fungal disease called Botryosphaeria canker. Affected trees show wilting or “flagging” of terminal growth on the ends of branches. Dieback usually extends 4 to 6 inches down the twig with leaves bending back toward the twig before turning brown. Dead leaves remain attached to the tree. If you look closely at the twig, you should see a rather marked transition from healthy to diseased tissue. Take a knife and scrape away some of the outer bark tissue. Healthy tissue is light green. Diseased tissue tends to be brown to black.

Botryosphaeria canker differs from oak wilt in that only the tips of branches are affected. Oak wilt affects whole branches. This disease causes such minor damage that chemical control measures are unwarranted. Dead twigs on small trees may be pruned off if desired. (Ward Upham)

Spring Flowering Shrubs

August through September is the time period our spring-flowering shrubs set flower buds. Therefore, watering, as needed, at this time can help with next spring’s bloom. Examples of spring-flowering shrubs include Forsythia, Flowering Quince, Almond, Beautybush, Deutzia, Pyracantha, Lilac, Mock Orange, Cotoneaster, Weigela, Viburnum and Witchhazel. (Ward Upham)

Contributors: Ward Upham, Extension Associate

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Horticulture Newsletter 2016, No. 12

3/22/2016

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Video of the Week:
Caring for Knockout Roses

Upcoming Events:

Hands-On Mushroom Cultivation Workshop

Friday, April 1 or Saturday, April 2

Topics Covered:
Growing oyster mushrooms on straw and sawdust
Inoculating shiitake mushroom logs (hands-on)
Growing winecap mushrooms in woodchips or straw mulch
Log selection and harvest

Each participant will receive:
Oyster Mushroom Production Bag
Inoculated Shiitake Log

Cost of the workshop: $25

For details, see http://www.reno.k-state.edu/docs/Mushroom%20workshop%20flyer.pdf or call
620-662-2371.

Vegetables:
Frost Proof Vegetable Plants

Certain vegetables can withstand cold spring temperatures as long as they have been toughened up by gradually exposing them to sunlight and outdoor temperatures. This “hardening off” process usually takes about a week.

Reducing watering and temperature is the key to toughening up transplants. If possible, move transplants outside for a portion of each day. Start by placing them in a shady, protected location and gradually move them into a more exposed, sunny location as the week progresses. Hardened off cabbage, broccoli, cauliflower and onions can withstand temperatures near 20 F without being killed. Lettuce plants are not quite as tough but will be okay if exposed to temperatures in the mid 20s.

Don’t hesitate to put these plants out now if extreme cold is not forecast. (Ward Upham)

Asparagus Time

Asparagus is one of those vegetables where freshness is incredibly important. If you have never eaten asparagus fresh out of the garden, try it. It may convince you to grow some of your own. For those who have an asparagus patch, the new spears should be appearing soon. The first asparagus that comes through the ground always seems to take a long time to reach harvest size. That is because asparagus growth is temperature dependent. The higher the day and nighttime temperatures, the faster it grows. Also, the longer the spear, the quicker the growth. As the season progresses and spears get longer, the growth rate increases.

Harvest asparagus by snapping or cutting. Snapping is quick and easy. Simply bend the stalk near the base until it breaks. Snapped ends dry quickly so refrigerate or use soon after harvest. If you cut asparagus, use a sharp knife to detach the spears slightly below ground level. This base is woodier than snapped asparagus, so it doesn't lose water as quickly. Cut off woody ends before cooking. (Ward Upham)

Herbicides for Home Gardens

Though mulches and hoeing are usually all that is needed for small vegetable gardens, homeowners with large areas may need the help of herbicides to keep ahead of the weeds. One preemergence and one postemergence herbicide can be used on home vegetable gardens.

The preemergence herbicide is trifluralin. Preemergence herbicides kill weed seeds as they germinate. They usually have no effect on weeds that have emerged. Therefore, they must be put on either before weeds come up in the spring or after weeds have been physically removed. The preemergence herbicide trifluralin is sold under the trade names of Treflan, Preen, Miracle-Gro Garden Weed Preventer, Gordon's Garden Weed Preventer Granules and Monterey Vegetable and Ornamental Weeder.

The postemergence herbicide is sethoxydim. This product only kills grasses; broadleaves are not affected. It can be sprayed directly over the top of many vegetables. Sethoxydim is sold as Poast, Monterey Grass Getter, and Hi-Yield Grass Killer. A second postemergence herbicide called fluazifop-p-butyl is labeled for commercial growers as Fusilade, but I haven't found vegetables listed on the homeowner labels, “Over the Top Grass Killer” and “Grass-No-More.” Also, the other homeowner products mentioned above often do not have as many vegetables on the label as the commercial products. Even among the homeowner products with the same active ingredient, there may be slight differences among labels. Check product labels to be sure the crop is listed. Here is a list of herbicides and the crops for which they are labeled. Many of these crops have application restrictions. For example, trifluralin can be used on asparagus, but must be applied before spears emerge. (Ward Upham)

Fruit:
Apple Tree Sprays

Two common diseases on apple trees are cedar apple rust and apple scab. Though some apple varieties are resistant to these diseases — including Liberty, Jonafree, Redfree, Freedom, Williams Pride and Enterprise — most varieties are susceptible. For a listing of the disease resistance of various cultivars, go to: http://extension.missouri.edu/explorepdf/agguides/ hort/g06022.pdf

Fungicide sprays during April and May are critical to preventing disease on susceptible varieties. With the warm spring this year, we may have to start sprays in March. The first spray should go down when leaves appear. A fungicide that is available to homeowners and very effective for control of apple scab and cedar apple rust is myclobutanil (Immunox). There are several formulations of Immunox but only one is labeled for fruit. Check the label.

Sprays should be done on a 7- to 10-day schedule to keep the protective chemical cover on the rapidly developing leaves and fruit. An insecticide will need to be added to this mixture after petal drop to prevent damage from codling moths that cause wormy apples. Methoxychlor or malathion can be used as an insecticide. In order to protect bees, DO NOT use any insecticide during bloom. Check the malathion label before purchase as not all labels list fruit.

Although gardeners may continue to use myclobutanil throughout the season, certain other fungicides are more effective on summer diseases such as sooty blotch and fly speck. Consider switching to Captan or to a fruit spray mixture about June 1. A spreader-sticker can be added to the fungicide-insecticide chemical mixture to improve the distribution and retention of the pest control chemicals over the leaves and fruit. A hard, driving rain of about 1 inch or more will likely wash chemicals from the leaves and fruit. In such cases, another application should be made. You can find information on controlling insects and diseases on fruit trees in our publication titled "Fruit Pest Control for Home Gardens" at http://www.ksre.ksu.edu/bookstore/pubs/c592.pdf Below is the spray schedule I use. Sprays are applied ever 10 days until 2 weeks before harvest.

Leaves Appear: Immunox
Petal Drop: Add malathion to the Immunox and so the mixture is Immunox + malathion
June 1: Replace Immunox with Captan. The mixture is now Captan + malathion

Stop spraying 2 weeks before harvest. (Ward Upham)

Turfgrass:
Core Aeration of Cool-Season Grass

If you are planning to core-aerate your tall fescue or Kentucky bluegrass lawn this spring, March or early-April is the time. Coring early in the spring gives cool-season lawns a chance to recover before crabgrass and other warm-season annual weeds start to germinate.

Core-aerating is one of the best things you can do for your lawn. It relieves compaction, hastens thatch decomposition, increases water infiltration and helps promote better root growth. Pay attention to the soil moisture level when coring. The soil should easily crumble when worked between the fingers. If it is too wet, the machine's tines will plug and it will merely punch holes in the wet soil, which increases compaction. If it is too dry, the tines will not be able to penetrate deeply enough to be of benefit. (Ward Upham)

Ornamentals:
Hackberry Psyllid, the Tiny "Gnat" Invading Homes

It is rare to find a hackberry tree without round growths on the underside of the leaves. These bumps, or galls, are the result of a tiny insect known as the hackberry psyllid. Hackberry is the only known host of this pest.

The adults of these insects are tiny and resemble miniature cicadas. They are dark reddish-brown with mottled wings. Most emerge from the galls during warm days in September and are very annoying as they gather around window screens seeking entry into the house. They are tiny enough to crawl through the openings in most screens. In the spring, the adults become active about the time the leaf buds open. The female lays her eggs on the underside of the developing leaves. Egg hatch occurs in 7 to 10 days, and the young nymphs begin to feed immediately. The leaf reacts to the feeding by producing a pouch or gall that entirely encloses the nymph.

Control is difficult. Adults that invade homes can be collected by using a vacuum sweeper but the bag should be discarded or the adults will escape. Since these insects do not seriously affect the vitality of the hackberry tree, control is usually not recommended. (Ward Upham)

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Horticulture Newsletter 2015, No. 34

8/25/2015

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Video of the Week:
Overseeding Your Lawn

Turfgrass:
Power Raking and Core-Aeration

September is the optimum time to power rake or core-aerate tall fescue and Kentucky bluegrass lawns. These grasses should be coming out of their summer doldrums and beginning to grow more vigorously. This is a good time to consider what we are trying to accomplish with these practices.

Power raking is primarily a thatch control operation. It can be excessively damaging to the turf if not done carefully. For lawns with one-half inch of thatch or less, I don’t recommend power raking but rather core aeration. For those who are unsure what thatch is, it is a springy layer of light-brown organic matter that resembles peat moss and is located above the soil but below the grass foliage. Power raking pulls up an incredible amount of material that then must be dealt with by composting or discarding.

Core-aeration is a much better practice for most lawns. By removing cores of soil, core-aeration relieves compaction, hastens thatch decomposition, and improves water, nutrient, and oxygen movement into the soil profile. This operation should be performed when the soil is just moist enough so that it crumbles easily when worked between the fingers. Enough passes should be made so that the holes are spaced about 2 to 3 inches apart. Ideally, the holes should penetrate 2.5 to 3 inches deep. The cores can be left on the lawn to decompose naturally (a process that usually takes two or three weeks, depending on soil-type), or they can be broken up with a power rake set just low enough to nick the cores, and then dragged with a section of chain-link fence or a steel doormat. The intermingling of soil and thatch is beneficial to the lawn. (Ward Upham)

Turf in Shade

We are often asked, “What’s the best shade grass for Kansas?” The answer is simple but requires explanation. Tall fescue is the best shade grass for Kansas. That does not mean that tall fescue is the best shade grass of all those grown. True fine leaf fescues such as sheep’s fescue, hard fescue, and creeping red fescue are actually better adapted to shade than tall fescue, but they have difficulty surviving Kansas summers. It might be better to say that tall fescue is the best shade grass adapted to Kansas conditions. Although tall fescue is our best shade grass, that does not mean that tall fescue is all that good in the shade. Large trees that produce deep shade will not allow tall fescue to survive over the long term. I say “over the long term” because fall-planted cool-season grasses will often do well under shade trees through the fall and spring when there is less leaf cover and growing conditions are better (cooler and moister) than in the summer. We often see people plant tall fescue in the shade each fall and then wonder what happens the following summer. The answer is stress from multiple fronts. Sunlight that passes through the leaves of trees has had most of the “good” light that drives photosynthesis stripped out. The grass struggles to make the food it needs for survival and growth. When this poor diet is combined with the additional stresses of drought and heat, tall fescue is unable to survive.

So, what should you do if you have too much shade for your turf? You have three choices. Reduce the shade by pruning up the lower branches of your trees so more early and late sun reaches the turf. This is not practical with many trees because it can destroy the desired shape. A second option is to plant a groundcover that is well-adapted to shady sites such as periwinkle or English ivy. Another solution would be to mulch the area under the tree. (Ward Upham)

Fruit:
Small Peaches

Late frosts that kill peach flowers are common in Kansas. Many areas will not have a full peach crop except for about one in every seven (or more) years. This year has been exceptional, with full fruit crops and excellent peach-growing weather in most areas. However, we have been receiving reports of trees with small peaches. Though small fruit could be due to poor weather (rare this year) or heavy fruit crops (common), there is a third possibility that is often overlooked. That possibility occurs when the top portion of the peach dies and the rootstock puts up new growth.

Peaches, like other fruit plants, must be vegetatively propagated. In other words, you cannot grow fruit from seed and expect the progeny to share the same characteristics as the parent. Therefore, good fruit trees have a top portion called the scion (the good fruiting part) and a bottom portion known as the rootstock. This combination is made by grafting or budding the scion onto the rootstock. Virtually everything above ground will be the scion and everything below ground will be the rootstock. The rootstock may keep the tree smaller, be more disease resistant than the scion, delay bloom or give some other good characteristic to the tree. However, the rootstock normally does not produce good, high quality fruit. Therefore, if the scion dies and the rootstock throws up new growth, the fruit produced will most likely be of poor quality.

How do you tell if the small fruit is due to a rootstock taking over? If the fruit produced is always poor quality, then suspect the rootstock problem. If this is the case, there is no remedy. The tree will not produce good quality fruit regardless of the care given. It would be best to remove and replace the tree. (Ward Upham)

Flowers:
Peonies May Be Cut Back Now

Peonies often look a little bedraggled by this time of year and gardeners may want to cut them back. That will not be a problem with this perennial. Peonies are essentially dormant by September 1, even though leaves may still be green. Cut leaves off close to the ground and compost or discard. (Ward Upham)

Ornamentals:
Spring Flowering Shrubs

August through September is the time period our spring flowering shrubs set flower buds. Therefore, watering, as needed, at this time can help with next spring’s bloom. Examples of spring flower shrubs include Forsythia, Flowering Quince, Almond, Beautybush, Deutzia, Pyracantha, Lilac, Mock Orange, Cotoneaster, Weigela, Viburnum and Witchhazel. (Ward Upham)

Mycosphaerella Leaf Spot on Ash

With all the concern about Emerald Ash Borer (EAB), many people may assume the trees are being attacked by EAB. However, EAB has only been confirmed in Johnson, Leavenworth and Wyandotte counties.

Mycosphaerella leaf spot causes small, brown spots that enlarge to become blotches and may result in early leaf drop. Though this disease looks serious, it is not. Defoliation this late in the growing season will not hurt the health of the tree. Therefore, because this disease appears sporadically and tree health is not harmed, we do not recommend treatment. Furthermore, treatment would have to be preventative and applied before the disease had infected the leaves. Applying a fungicide now would have no effect. (Ward Upham)

Pests:
Fall Webworm

On a return trip to Manhattan Monday, I noted the presence of fall webworms along the roadway --- sometimes one or two in an occasional tree here and there, or (in this instance) numerous web masses. These did not develop “overnight.” Judging by their size, these colonies likely were initiated 4-5 weeks earlier. People may worry about the impact of feeding depredations, but it is minimal. A healthy tree will not be hurt. Probably a more verbally expressed concern is the unsightliness created by the webbing, as well “creepy” clumps of caterpillars within.

A common recommendation is to prune out webbed branches. One must consider the accessibility of web masses --- those beyond reach simply allowed to remain. Pruning might be doable if just a branch or two ---- but possibly unacceptable and disfiguring when trees are heavily infested with web masses.If within reach, consider an implement (of sorts) to “rake out”/remove webbing. And what implement could be more handy (yes, pun intended) than one’s own hand. There is no need to fear the dry webbing and/or dried fecal deposits and squirmy caterpillar within. As webbing is removed, also removed will be the objectionable dead/dry foliage and the fall webworms. Simply dispose of the gathered material. All that is left behind is the leafless (but still living) branch and its’ intact buds which will produce the ensuing year’s foliage. (Bob Bauernfeind)

Contributors: Ward Upham, Extension Associate; Bob Bauernfeind, Extension Entomologist

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Horticulture Newsletter 2015, No. 11

3/17/2015

0 Comments

Video of the Week:
Pruning Fruit Trees

Turfgrass:
Core Aeration of Cool-Season Lawns

If you are planning to core-aerate your tall fescue or Kentucky bluegrass lawn this spring, reserve a machine now so you can get the job done in March or early-April. Coring early in the spring gives cool-season lawns a chance to recover before crabgrass and other warm-season annual weeds start to germinate.

Core-aerating is one of the best things you can do for your lawn. It relieves compaction, hastens thatch decomposition, increases water infiltration and helps promote better root growth. Pay attention to the soil moisture level when coring. The soil should easily crumble when worked between the fingers. If it is too wet, the machine's tines will plug and it will merely punch holes in the wet soil, which increases compaction. If it is too dry, the tines will not be able to penetrate deeply enough to be of benefit. (Ward Upham)

Vegetables:
Frost Proof Vegetable Plants

Certain vegetables can withstand cold spring temperatures as long as they have been toughened up by gradually exposing them to sunlight and outdoor temperatures. This “hardening off” process usually takes about a week. Reducing watering and temperature is the key to toughening up transplants. If possible, move transplants outside for a portion of each day. Start by placing them in a shady, protected location and gradually move them into a more exposed, sunny location as the week progresses. Hardened off cabbage, broccoli, cauliflower and onions can withstand temperatures near 20 F without being killed. Lettuce plants are not quite as tough but will be okay if exposed to temperatures in the mid 20s. Don’t hesitate to put these plants out now if extreme cold is not forecast. (Ward Upham)

Controlling Weeds in Home Garden Asparagus Beds

The best time to control weeds in asparagus is early spring before the asparagus emerges. A light tilling (or hoeing) that is shallow enough to avoid the crowns will eliminate existing weeds. Many gardeners like to mix in organic matter during the same operation.

Herbicides can be used before asparagus emerges. Glyphosate (Roundup, Killzall) will kill weeds that are actively growing, and the preemergence herbicide trifluralin can be used to kill weed seeds as they germinate. Trifluralin is found in several products, but not all of them list asparagus on the label. Those that do have asparagus on the label include Miracle-Gro Weed Preventer Granules and Monterey Vegetable and Ornamental Weeder. Mulch can also be used to keep weeds from invading.

No herbicides can be used during harvest. The end of harvest presents another opportunity. Remove all fern and spears and apply Roundup to control virtually all of the weeds present. Past the harvest season and after regrowth of the asparagus, options are limited. Products that contain sethoxydim can be applied to asparagus to kill grassy weeds. Sethoxydim has no effect on broadleaves including asparagus. Two sethoxydim products available to homeowners and labeled for asparagus are Monterey Grass Getter and Hi-Yield Grass Killer. With broadleaves, the only option is to pull them and look forward to next year. (Ward Upham)

Remove Fern and Fertilize Asparagus

If you haven’t removed last year’s growth from asparagus plants, now is the time. Asparagus comes up around the first of April in Manhattan but will be earlier in southern Kansas and a bit later further north.

Also, asparagus benefits from a fertilizer application early spring. Fertilize according to a soil test or add 1 to 2 pounds of a 10-20-10 fertilizer per 20 feet of row before growth starts. If a soil test shows that only nitrogen is needed, apply 1 pound of a 16-0-0 product or ½ pound of a 30-4-5, 27-3-3 or similar fertilizer per 20 feet of row. Incorporate lightly with a tiller or rake in fertilizer before spears emerge. Fertilize again at the same rate after the last harvest. (Ward Upham)

Flowers:
Pruning Hybrid-Tea Roses

The best time to prune roses is in the spring before new growth appears and after danger of killing frost. Be sure to remove dead stubs. Otherwise, canker fungi may invade stubs and progress into healthy tissue during the summer. Use sharp shears and make cuts at a 45-degree angle about a quarter-inch above healthy buds. How much to prune after dead wood removal depends on the type of rose.

For shrub roses, pruning usually consists of removing dead wood or light pruning for shaping. This article focuses on hybrid tea roses which require much more extensive pruning. With hybrid teas, there are three pruning styles, each with a specific purpose. Heavy or severe pruning is done on well-established, vigorous plants to produce large, showy flowers. Prune back to three to four healthy canes with three to six eyes per cane. Canes normally will be 6 to 12 inches long. Moderate pruning is done on well-established, healthy plants and is designed to increase the number of flowers produced rather than increase flower size. Leave five to six healthy canes with at least seven buds per cane. Prune stems to 12 to 18 inches long. Light pruning rejuvenates plants after years of neglect or may be performed on newly established plants. Leave five to seven canes of about 18 inches or more in length. This helps maximize leaf area for energy production and rejuvenates plants.

If your plants suffered a significant amount of winter damage, they may need to be cut back more severely than even the heavy-pruning style. This will result in a few large flowers but in this case is your only option. (Ward Upham)

Ornamentals:
Breaking the Pine Wilt Cycle

Pines have several disease and insect problems. One of them is pine wilt disease. It kills the entire tree quickly.

Pine wilt is caused by the pinewood nematode, a microscopic worm. The nematode is spread by the pine sawyer beetle. The nematode feeds and multiplies in the tree’s resin canals, causing wilting and death in several weeks to several months. The nematode and beetles spend the winter in the infected tree. In spring, the beetles emerge starting around May 1, carrying nematodes to new trees and continuing the cycle of infection.

The disease is common in the eastern half of the state, and it is spreading west around 10 miles per year. There have been pockets of infection in the western part of the state.

In Kansas, new pine wilt infections are most visible from August to December. Trees wilt and die in a short period of time, from several weeks to a few months. In the first stages, the needles turn grey or green, then yellow and brown. The discoloration sometimes occurs branch by branch, sometimes all at once. With pine wilt, eventually the whole tree dies, within a few months. The brown needles stay on the tree for up to a year after the tree has died. Another key symptom is reduced resin. On a healthy tree, sticky resin bleeds from the site of a wound. In contrast, if a tree has pine wilt, the resin is often reduced or absent, and branches become dry or brittle.

There is a website with color photos and descriptions at the following link: http://muextension.missouri.edu/explorepdf/miscpubs/mx0858.pdf

There are images to compare and contrast pine wilt with other pine diseases here: http://www.ksre.ksu.edu/bookstore/pubs/l722.pdf

With the other diseases (tip blight, needle blight) only parts of the tree turn brown. With pine wilt, the whole tree is brown and dead. If you aren’t sure if your tree has pine wilt or something else, contact your local K-State Research and Extension Office or the K-State Diagnostic Lab (clinic@ksu.edu).

If a tree has pine wilt, the tree should be cut down by April 1 to make sure there is time to destroy the wood by May 1, when the beetles start to some out. Cut the tree to the ground—don’t leave a stump. Chip or burn the wood immediately to destroy the beetles and nematodes. Don’t keep pine wood around for firewood. (Megan Kennelly)

Wild Garlic, Wild Onion, and Star-of-Bethlehem

Wild garlic (Allium vineale) and wild onion (Allium canadense) are two closely related plants that can become weed problems in home lawns and landscapes. Though wild garlic and wild onion look much alike, each has an odor that is characterized by its name – wild garlic smells like garlic and wild onion smells like onion. These plants are perennials that can also reproduce by seeds and aerial bulbils. Bulbils form at the top of the stem and are oval and smooth. Wild garlic also reproduces by underground bulb offsets, but wild onion does not. Both species produce a clump of plants that is unsightly in a lawn. Control recommendations are the same though we now have a couple of new additions to our arsenal.

Traditionally we have used 2,4-D or 2,4-D + MCPP + Dicamba (i.e., Trimec, Weed-Out, Weed-B-Gon). These products should be sprayed during March on a day that is at least 50 degrees. Newer products are Weed Free Zone and Speed Zone. Both are combination products that contain a formulation of Trimec plus carfentrazone. These will give a quicker response at cooler temperatures near 50 degrees. A spreader-sticker added to the spray should help any of these products be more effective. At times, the spreader-sticker is already mixed into the weedkiller; no additional amount is needed. These herbicides are also effective on dandelions.

Unfortunately, we have not had a good chemical control for Star-of-Bethlehem. The best products we had were Coolpower (31.3% control) and Turflon Ester (23.8% control). Coolpower is a commercial only product, but Turflon Ester is available to both commercial and homeowner users. But research out of Virginia Tech has improved our outlook. Scientists there did a study in which they gained 96% control of Star-of-Bethlehem one month after treatment by using Quicksilver, a formulation of carfentrazone at the rate of 4 fl. oz/A. Quicksilver is a commercial only product, and therefore is not available to homeowners. However, both Speed Zone and Weed Free Zone contain carfentrazone and would certainly be worth a try if you have this troublesome plant. (Ward Upham)

Contributors: Megan Kennelly, Plant Pathologist; Ward Upham, Extension Associate

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Power Raking and Core-Aeration

Horticulture Newsletter 2016, No. 35

Video of the Week:
Pears, Tips on Harvesting

Turfgrass:
Fall Lawn Seeding Tips

Overseeding a Lawn

Power Raking and Core-Aeration

Flowers:
Dividing Peonies

Miscellaneous:
Twig Dieback on Oak

Spring Flowering Shrubs

Horticulture Newsletter 2016, No. 12

Video of the Week:
Caring for Knockout Roses

Upcoming Events:

Vegetables:
Frost Proof Vegetable Plants

Asparagus Time

Herbicides for Home Gardens

Fruit:
Apple Tree Sprays

Turfgrass:
Core Aeration of Cool-Season Grass

Ornamentals:
Hackberry Psyllid, the Tiny "Gnat" Invading Homes

Horticulture Newsletter 2015, No. 34

Video of the Week:
Overseeding Your Lawn

Turfgrass:
Power Raking and Core-Aeration

Turf in Shade

Fruit:
Small Peaches

Flowers:
Peonies May Be Cut Back Now

Ornamentals:
Spring Flowering Shrubs

Mycosphaerella Leaf Spot on Ash

Pests:
Fall Webworm

Horticulture Newsletter 2015, No. 11

Video of the Week:
Pruning Fruit Trees

Turfgrass:
Core Aeration of Cool-Season Lawns

Vegetables:
Frost Proof Vegetable Plants

Controlling Weeds in Home Garden Asparagus Beds

Remove Fern and Fertilize Asparagus

Flowers:
Pruning Hybrid-Tea Roses

Ornamentals:
Breaking the Pine Wilt Cycle

Wild Garlic, Wild Onion, and Star-of-Bethlehem

Authors

Subscribe to the newsletter by entering your e-mail and clicking the link below

Archives

Categories

Power Raking and Core-Aeration

Horticulture Newsletter 2016, No. 35

Video of the Week:Pears, Tips on Harvesting

Turfgrass:Fall Lawn Seeding Tips

Overseeding a Lawn

Power Raking and Core-Aeration

Flowers:Dividing Peonies

Miscellaneous:Twig Dieback on Oak

Spring Flowering Shrubs

Horticulture Newsletter 2016, No. 12

Video of the Week:Caring for Knockout Roses

Upcoming Events:

Vegetables:​Frost Proof Vegetable Plants

Asparagus Time

Herbicides for Home Gardens

Fruit:Apple Tree Sprays

Turfgrass:Core Aeration of Cool-Season Grass

Ornamentals:​Hackberry Psyllid, the Tiny "Gnat" Invading Homes

Horticulture Newsletter 2015, No. 34

Video of the Week:Overseeding Your Lawn

Turfgrass:Power Raking and Core-Aeration

Turf in Shade

Fruit:Small Peaches

Flowers:Peonies May Be Cut Back Now

Ornamentals:Spring Flowering Shrubs

Mycosphaerella Leaf Spot on Ash

Pests:Fall Webworm

Horticulture Newsletter 2015, No. 11

Video of the Week:Pruning Fruit Trees

Turfgrass:Core Aeration of Cool-Season Lawns

Vegetables:Frost Proof Vegetable Plants

Controlling Weeds in Home Garden Asparagus Beds

Remove Fern and Fertilize Asparagus

Flowers:Pruning Hybrid-Tea Roses

Ornamentals:Breaking the Pine Wilt Cycle

Wild Garlic, Wild Onion, and Star-of-Bethlehem

Authors

Subscribe to the newsletter by entering your e-mail and clicking the link below

Archives

Categories

Video of the Week:
Pears, Tips on Harvesting

Turfgrass:
Fall Lawn Seeding Tips

Flowers:
Dividing Peonies

Miscellaneous:
Twig Dieback on Oak

Video of the Week:
Caring for Knockout Roses

Vegetables:
Frost Proof Vegetable Plants

Fruit:
Apple Tree Sprays

Turfgrass:
Core Aeration of Cool-Season Grass

Ornamentals:
Hackberry Psyllid, the Tiny "Gnat" Invading Homes

Video of the Week:
Overseeding Your Lawn

Turfgrass:
Power Raking and Core-Aeration

Fruit:
Small Peaches

Flowers:
Peonies May Be Cut Back Now

Ornamentals:
Spring Flowering Shrubs

Pests:
Fall Webworm

Video of the Week:
Pruning Fruit Trees

Turfgrass:
Core Aeration of Cool-Season Lawns

Vegetables:
Frost Proof Vegetable Plants

Flowers:
Pruning Hybrid-Tea Roses

Ornamentals:
Breaking the Pine Wilt Cycle