We are starting to receive questions on whether it is best to cut back ornamental grasses in the fall or spring. As a rule, ornamental grasses should not be cut back while green because they need time to move the energy found in the foliage into the roots. Even when browned by cold weather, most gardeners will leave the foliage until spring because of the interest it adds to winter landscapes. Early March is the preferred time to cut back these plants. However, dry foliage is extremely flammable and should be removed in the fall from areas where it is a fire hazard. 
​
Another question we often receive is whether we can divide ornamental grasses in the fall. Spring is the preferred time because divisions done in the fall may not root well enough to survive the winter. (Ward Upham)

March is a good time to remove dead foliage from ornamental grasses. Grasses green up earlier if foliage is removed and are more attractive without a mixture of dead and live leaves. A number of tools can be used including hand clippers, weed whips (if the foliage is of a small enough diameter), weed whips with a circular blade, or even a chain saw. Use the top of the chainsaw bar to cut so the saw doesn't pull in debris and clog.

Also, it is often helpful to tie foliage together before cutting so it doesn't interfere and is easier to dispose of. Burning is another option — but only if it is safe and legal to do so. Note that these grasses may not burn long, but they burn extremely hot. Even so, the crown of the plant is not damaged and new growth appears relatively quickly.
 
If the center of the clump shows little growth, the plant would benefit from division. Dig up the entire clump and separate. Then replant the vigorous growth found on the outer edge of the clump. (Ward Upham)

Though we had some fall armyworms last year, the last time we had a significant outbreak on turf was August, 2000. Armyworms are so-called because they invade fields or landscapes as large groups and can cause a lawn to turn brown seemingly overnight.
 
Young worms are ½ to 3/4 inch long. Mature ones are 1 ½ inches long. Body color may vary from green to almost black but light stripes will be visible along the length of the body. Look for a whitish inverted "Y" on the top of the black head. It normally takes 2 to 3 weeks to progress from egg to pupa. The adult is a moth.
 
Armyworm damage can resemble drought damage but close inspection of the turf will reveal the larvae. Look for active feeding during early morning or evening hours or on cloudy days. Larvae feed on foliage and the resulting dehydration
causes to turf to quickly brown. Normally, armyworm damage does not kill established turf but may if populations are high enough. Thick infestations of fall armyworm can damage turfgrass crowns which will kill turf.
 
Carbaryl (Sevin), acephate (Orthene, Acephate), spinosad (Conserve; Captain Jack’s Dead Bug Brew; Borer, Bagworm, Leafminer and Tent Caterpillar Spray) and other insecticides are effective caterpillar killers. Treat in late afternoon, when the caterpillars are likely to begin feeding. Do not mow for 3 days after treatment. (Ward Upham)

​If you plan to develop or add to your fruit garden next year, now is a good time to begin preparing the planting site. Grass areas should be tilled so grass does not compete with the fruit plants for soil moisture and nutrients. Have the soil analyzed for plant nutrients. Your local K-State Research and Extension agents have information to guide you in taking the soil sample. From that sample, the agent can provide recommendations on what and how much fertilizer to add to correct nutrient deficiencies. Organic materials such as compost, grass clippings, leaves, hay, straw or dried manure, can be tilled into the soil to help improve its condition. Time and weather conditions generally are more suitable in the fall than in the late winter and spring for preparing soil. If fruit plants can be set by early April, they will have developed a stronger root system to support plant growth than they would if planted later.
 
If there are only a few plants to be planted, consider tarping each planting area to guard against a wet spring, delaying planting after plants are shipped and received.
 
Also, fruit tree planting can be done in the fall but plants may need to be watered during the winter if the weather is warm and dry. (Ward Upham)

October is the month that existing beds of spring-flowering bulbs such as daffodils and tulips are fertilized. If bulbs have been fertilized in the past, there is often plenty of phosphorus and potassium in the soil though it is best to take a soil test to be certain. If the soil needs phosphorus and potassium, use a complete fertilizer (such as 10-10-10, 9-9-6, etc.) at the rate of 2.5 lbs. per 100 square feet. This would equal 1 rounded teaspoon per square foot. If phosphorus and potassium are not needed, blood meal makes an excellent fertilizer. It should be applied at the rate of 2 pounds per 100 square feet or 1 teaspoon per square foot. Turf fertilizers such as a 27-3-3 or 30-3-3 can be used, but cut the rate by a third.
 
If there is difficulty in determining exactly where the bulbs are planted due to the lack of foliage, fertilizing in the spring rather than the fall is acceptable. However, it is important that the plants are fertilized when the foliage first shows. Waiting until the bulbs are flowering is too late as the roots have already begun to shut down. (Ward Upham)

Many young, smooth, thin-barked trees such as honey locusts, fruit trees, ashes, oaks, maples, lindens, and willows are susceptible to sunscald and bark cracks. Sunscald normally develops on the south or southwest side of the tree during late winter. Sunny, warm winter days may heat the bark to relatively high temperatures. Research done in Georgia has shown that the southwest side of the trunk of a peach tree can be 40 degrees warmer than shaded bark. This warming action can cause a loss of cold hardiness of the bark tissue resulting in cells becoming active. These cells then become susceptible to lethal freezing when the temperature drops at night. The damaged bark tissue becomes sunken and discolored in late spring.  Damaged bark will eventually crack and slough off.
 
Trees often recover but need TLC — especially watering during dry weather. Applying a light- colored tree wrap from the ground to the start of the first branches can protect recently planted trees. This should be done in October to November and removed the following March. Failure to remove the tree wrap in the spring can prove detrimental to the tree. (Ward Upham)

We are starting to receive questions on whether it is best to cut back ornamental grasses in the fall or spring. As a rule, ornamental grasses should not be cut back while green because they need time to move the energy found in the foliage into the roots. Even when browned by cold weather, most gardeners will leave the foliage until spring because of the interest it adds to winter landscapes. Early March is the preferred time to cut back these plants. However, dry foliage is extremely flammable and should be removed in the fall from areas where it is a fire hazard.
 
Another question we often receive is whether we can divide ornamental grasses in the fall. Spring is the preferred time because divisions done in the fall may not root well enough to survive the winter. (Ward Upham)

October is a good time to plant garlic (Allium sativum) if you want large quality cloves next summer. Apply 3 pounds of 10-10-10 fertilizer per 100 square feet and mix into the soil before planting or fertilize according to soil test. Plant individual cloves point up and spaced 6 inches apart and 1 to 2 inches deep. The larger the clove planted, the larger the bulb at harvest. Water in well and mulch with straw to conserve soil warmth and encourage good establishment. Harvest will not occur until next summer. Test dig when the lower 1/3 of the foliage is yellow. If the cloves have segmented, it is time to harvest. If they haven't segmented, wait another week or two. Elephant garlic (Allium ampeloprasum) should also be planted now. It is a plant with a milder garlic flavor and is actually a closer relative to the leek than to true garlic. (Ward Upham)
 
Contributors: Ward Upham, Extension Associate

We now have 3 years worth of  data on 12 different varieties of tomato.  Tom Fowler, Horticulture Specialist with the University of Missouri Extension Service, took data on large tomato plantings in 2013, 2014 and 2015.  Though his study included many more than 12 varieties, we have focused on the 12 that were grown all three years.  A single year’s data is often unreliable as the weather may have played a large part in results.  A variety that does very well under certain conditions, may not do well under less favorable conditions. Other varieties may be more forgiving and yield well under a wider range of conditions.  Two years data is better at balancing weather effects but we often like to see 3 years to feel more comfortable in making recommendations.
 
The data below is from an average of all three years. We list both yield in pounds per plant and individual fruit size in ounces.
 
                                     Lbs/Plant      Ounces/Fruit
Celebrity                      14.66                    6.25
Beefmaster                  12.84                   7.56
Crista                             12.71                     6.18
Big Beef                         12.60                   6.37
Hy-Beef                         12.33                   5.50
Jet Star                          10.76                   5.65
Rutgers                         10.43                   4.31
BHN 961                        9.82                    7.06
Black Krim                   9.69                    6.62
Florida 91                     9.25                     6.63
Supersonic                   8.69                     6.62
Amana Orange           6.58                      11.82

These are all modern varieties except for the heirlooms Amana Orange, Rutgers and Black Krim.
 
Remember these results are from north of Kansas City and include only 12 varieties.  Variety performance differs by location.  New gardeners or those that want to try a new tomato variety should use this list as a guide. However, pay attention to what other local gardeners have had good success with and to the recommendations of your local garden center. They may be able to point to a variety that does especially well in your area.  (Ward Upham)

Broccoli, cabbage and cauliflower are cole crops that have a tendency to bolt (go to seed) or button (produce an extremely small head) if plants are not grown properly. These crops need to be kept actively growing through their production cycle, including growing transplants from seed. If they slow down due to under-fertilization or are stunted due to overgrowing their container, buttoning or bolting is more likely.  Therefore, be sure to properly fertilize plants grown from seed and ensure they have enough light.  The easiest way fertilize transplants is to use a potting soil with fertilizer already added.  Light may be more of a challenge.  Often natural sunlight is not sufficient unless the plants are in a greenhouse and additional light is needed.  Click here for a video on how to build a grow light.
 
If you are not growing your own transplants but rather selecting plants from a retailer, choose small, stocky dark green plants.  Even after transplanting, these plants need to be well-fertilized. Fertilize at transplanting with a starter solution and continue to fertilize every 2 to 3 weeks until harvest. Both buttoning and bolting are irreversible. Once a seed stalk starts for form, nothing can be done to force the plant to produce a normal crop. (Ward Upham)

March is a good time to remove dead foliage from ornamental grasses. Grasses green up earlier if foliage is removed and are more attractive without a mixture of dead and live leaves. A number of tools can be used including hand clippers, weed whips (if the foliage is of a small enough diameter), weed whips with a circular blade, or even a chain saw. Use the top of the chainsaw bar to cut so the saw doesn't pull in debris and clog.

Also, it is often helpful to tie foliage together before cutting so it doesn't interfere and is easier to dispose of.   Burning is another option — but only if it is safe and legal to do so. Note that these grasses may not burn long, but they burn extremely hot. Even so, the crown of the plant is not damaged and new growth appears relatively quickly.
 
If the center of the clump shows little growth, the plant would benefit from division. Dig up the entire clump and separate. Then replant the vigorous growth found on the outer edge of the clump. (Ward Upham)

​Gardeners are eager to get out and do something in the landscape this time of year. One chore that can be taken care of during March is pruning certain shrubs. Often, gardeners approach pruning with trepidation, but it is not as difficult as it may seem. Remember, not all shrubs need to be pruned (i.e., witch hazel), and certain shrubs, which will be identified later in this article, should not be pruned this time of year. Shrubs are pruned to maintain or reduce size, rejuvenate growth, or to remove diseased, dead or damaged branches. Deciduous shrubs are those that lose leaves each winter. Evergreen shrubs maintain foliage all year and include yews and junipers.
 
Deciduous shrubs are placed into three groups:
• Those that flower in the spring on wood produced last year;
• Those that flower later in the year on current seasons’ growth; and
• Those that may produce flowers, but those flowers are of little ornamental value.
 
Shrubs that flower in the spring should not be pruned until immediately after flowering.  Though pruning earlier will not harm the health of the plant, the flowering display will be reduced or eliminated. Examples of these types of plants include forsythia, lilac, flowering quince, Vanhoutte spirea, bridal wreath spirea and sweet mockorange.
 
Shrubs that bloom on current seasons’ growth or that do not produce ornamental flowers are best pruned in March.  Examples include Rose-of-Sharon, pyracantha, Bumald spirea, and Japanese spirea.  Pruning during the spring allows wounds to heal quickly without threat from insects or disease.  There is no need to treat pruning cuts with paints or sealers. In fact, some of these products may slow healing.

There are three basic methods used in pruning shrubs: thinning, heading back, and rejuvenating.
 
Thinning is used to thin out branches from a shrub that is too dense. It is accomplished by removing most of the inward growing twigs by either cutting them back to a larger branch or cutting them back to just above an outward- facing bud. On multi-stemmed shrubs, the oldest canes may be completely removed.
 
Heading back is done by removing the end of a branch by cutting it back to a bud and is used for either reducing height or keeping a shrub compact.  Branches are not cut back to a uniform height because this results in a "witches-broom" effect.
 
Rejuvenation is the most severe type of pruning and may be used on multi-stem shrubs that have become too large, with too many old branches to justify saving the younger canes. All stems are cut back to 3- to 5-inch stubs. This is not recommended for all shrubs but does work well for spirea, forsythia, pyracantha, ninebark, Russian almond, little leaf mock orange, shrub roses and flowering quince. (Ward Upham)

As outdoor plants break dormancy and start to grow in response to the longer days and warmer spring temperatures, houseplants usually put on a spurt of growth as well. Eventually, these indoor plants out-grow their containers and need to be repotted.
 
To check if your plants are becoming root bound and need a larger pot, inspect the root system. First, knock the plant out of its pot. Watering several hours before this operation will allow the plant to be removed more easily. On pots that are 8 inches in diameter or less, place one hand over the top of the pot with the stem of the plant passing between two fingers, and turn the plant upside down. Then rap the edge of the pot against a table. The root ball should come away from the pot. On pots that are more than 8 inches in diameter, a bit more encouragement may be needed. Place the pot on its side and rap the top edge of the pot with a rubber mallet. Turn the plant a few degrees, and repeat the procedure until the root ball releases.

Once the plant is free, take a look at the root ball. If you see a clear network of roots, the plant needs to be moved to a larger pot. If the original pot is less than 10 inches, move up an inch in size; if 10 inches or larger, increase the size 2 inches. If the pot has one or several large holes in the bottom for drainage, cover the holes with pot shards (pieces of a broken clay pot) or gravel so that the potting mix is not washed out during watering.
 
It is essential that the plant sit at the same level it was in the old pot. Add enough potting mix to the bottom of the pot to ensure this. This mix will need to be firmed before the plant is placed on top of it so it doesn't settle over time. After the plant is placed, fill in around the original root ball with potting soil. Again, firm this soil with a slender stick, or tap the bottom of the pot on the table. If this firming is not done, new soil will be so light and airy that water will tend to move through it rather than through the entire root ball.
 
Water the plant thoroughly after repotting, but be especially careful not to overwater for about two weeks. The new soil tends to stay wet until roots penetrate. Overwatering can lead to rot. Most plants need to be repotted annually though vigorous growers may need to move up sooner. Slow-growing plants may stay in the same pot for more than a year. (Ward Upham)

Plants that become dormant in preparation for winter must have a certain number of "chilling hours" before the buds will begin growth the next spring. "Chilling" hours are those in which the temperature remains between 32 and 45 degrees F.

Plants differ in the number of chilling hours needed, with those adapted to colder climates usually requiring more than those adapted to warmer zones. Even plants within the same species can differ markedly in the number of chilling hours required for bud break. For example, apple varieties range from a low of 250 (or fewer) chilling hours to a high of 1700.
 
The chilling requirements of some plants have been met already this winter. For these plants, dormancy is over and warm periods can lead to bud swell or even flowering.  If spring-flowering bulbs flower now, the floral parts may be damaged by a cold snap but the plants itself will likely be OK.  It all depends on the severity of the cold snap.
 
So what do you do if you have a plant that has swollen buds? Actually, there is not much you can do to slow the bud development process because it is completely dependent on weather. However, watering during dry weather may help in an indirect way. Roots can suffer drought damage during the winter. A tree with a damaged root system and damaged buds will be slower to recover than one with just damaged buds. Readily available soil moisture will aid in keeping the plant healthy so it will be better able to recover from cold damage. Also, it is important to determine if the swollen buds are flower buds or leaf buds. Even if the flower buds are killed by cold temperatures, the health of the plant should not be affected. If, in addition to the swollen buds, you also see small buds on the stems, then the swollen buds are flower buds and the small buds are leaf buds.

Leaf buds are more hardy than flower buds but even they can be killed if they have lost their winter hardiness.  Even if the leaf buds swell and are killed by a cold snap, a healthy tree will still be able to survive. There are secondary buds that remain dormant unless the primary bud is killed. Secondary bud growth may be slower and less vigorous, but the tree will eventually recover. (Ward Upham)
 
Contributors: Ward Upham, Extension Associate

Recently, we have received a number of calls from gardeners wanting to cut back shrubs. Though light pruning and removal of dead wood are fine this time of year, severe pruning should be left until spring. Keep in mind that even light pruning of spring-blooming shrubs such as lilac and forsythia will reduce flowers for next year. We normally recommend that spring-bloomers be pruned after flowering.
 
Shrubs differ in how severely they can be cut back. Junipers do not break bud from within the plant and therefore should be trimmed lightly if you wish to keep the full shape. Overgrown junipers should be removed. On the other hand, there are certain shrubs that can be pruned back severely during the spring. Rejuvenation is the most severe type of pruning and may be used on multi-stem shrubs that have become too large with too many old branches to justify saving the younger canes. All stems are cut back to 3- to 5-inch stubs. This works well for spirea, forsythia, pyracantha, ninebark, Russian almond, little leaf mock orange, shrub roses, and flowering quince. Just remember that spring is the correct time to do this, not now. (Ward Upham)

Ornamental grasses have really caught my eye this fall. The way the morning and evening light glitters through the seedheads is just gorgeous.

Never before have there been so many varieties of ornamental grasses from which to choose. Breeders are selecting for landscape performance, foliage color, seed head size and plant size. I think the most interesting feature of most ornamental grasses is the seed head, but foliage color is a close second. There are some newer varieties with deep purple leaves and names like ‘Hot Rod,’ ‘Fireworks’ and ‘Heavy Metal.’

Versatile is the word of choice for this category of plants. They can take tough sites, full sun and little nutrients or water (once established). Many are very tall and can screen unsightly features in the landscape, while others are short and (let me say it) cute. Yes, cute. Have you seen ‘Little Bunny’ pennisetum? Adorable. Plant enthusiasts are allowed to call plants adorable, you know.

What about ‘Blonde Ambition’ blue grama grass?   Oh yeah. This one is spunky and super cool. ‘Pink Cloud’ muhly grass is literally a cloud of pink blooms. These plants all look great planted en masse as well as in containers.
 
There are really only 3 simple things to remember about growing ornamental grasses in your landscape: planting time, trimming time and division time.
 
Planting time is most of the year except for winter. Plant once the danger of frost has passed in the spring, up until the end of September. If you plant them any later than that, it’s really too late. They don’t have adequate time to establish a strong root system and are in real danger of dying when cold weather hits. Better to wait until your investment can grow enough during the growing season to survive the winter (which they do very well, just need time to establish).
 
I have a bone to pick about trimming time. One of the main attributes I’m focusing on in this article is the seedheads of ornamental grasses. They certainly look their best right now, but they will also continue to look great for the next 6 months or so. This is their time to shine—winter interest is a main feature of ornamental grasses. Therefore…don’t cut them back until February or March as winter is ending and spring is beginning. I have seen far too many grasses cut back in their prime when it’s absolutely not needed. Grasses need to be trimmed to 6-8 inches in the
spring in order to let the fresh new growth get through the old biomass. Now, this is where it gets manly, I tell ya. Trimming ornamental grasses requires gloves, long sleeves and serious tools. If your grasses are really big, like Pampas Grass, you might even want a chainsaw and chaps. If smaller, you can probably get away with pruners or hedge trimmers. Compost all that good biomass for organic matter later in the year.
 
Division time is another time for manly tools. Every 3 to 4 years it’s a good idea to divide most ornamental grasses. By then, the center may start to die out and the plants begin to look somewhat unattractive as a clump. How do you divide grass clumps? With shovels and saws and axes. And maybe a machete—we use those in horticulture more often that you would imagine [side note: Can I have one for Christmas?]. Dig those plants out and redistribute them or give them away. I’ve even seen folks try to get rid of their divisions on Craigslist. Hey, worth a look if you want some plants for free!
 
This holiday season, consider glamming it up with the gift of glitter (gift certificate for planting ornamental grasses) and “tooling“ it up Tim Taylor Tool Time Style with some manly gardening tools. You already know what’s on my list. (Cheryl Boyer)

Winter can be a difficult time for strawberries in Kansas. Plants need time to become adjusted to cold weather and will gradually become more cold resistant as fall progresses. Strawberry plants are able to withstand colder temperatures in the middle of the winter than in the fall before they have gone through much cold weather. For example, if temperatures suddenly plummet below 20 degrees F before the plants harden to the cold, they can be severely damaged. A drop to 15 degrees F may kill them. Hardened plants can withstand such temperatures with ease. This lack of hardening off may be a concern this year because of the unseasonably warm fall. If a sudden drop in temperature to below 20 degrees F is forecast, it may be wise to mulch the plants as you would for the winter. After the cold snap is over, uncover the plants so they may continue to harden off.
 
Normally, strawberries should be mulched for the winter around Thanksgiving. However, if temperatures stay abnormally warm, give plants another couple of weeks to become cold hardy before mulching. Mulching plants helps protect strawberries not only from low temperatures but also from heaving damage. Heaving damage occurs when the alternate freezing and thawing common in Kansas winters heave plants out of the ground where the roots are exposed and the plants die from lack of water.
 
Wheat straw makes good mulch and is widely available. The straw should be spread over the plants to a depth of 3 inches. Shake the slabs of straw apart so there are no large compressed chunks. This straw mulch not only helps protect the plants over winter but can also help avoid damage from late spring frosts by delaying blooming a few days in the spring. Mulch should be removed gradually in the spring as plants begin new growth. Remove enough so leaves can be seen.
 
Leaving some mulch in place keeps the berries off the ground and conserves moisture. Also, mulch left in the aisles helps protect pickers from muddy conditions. (Ward Upham)

You may have heard that using wood ashes on your garden can help make the soil more fertile. Though ashes do contain significant amounts of potash, they contain little phosphate and no nitrogen. Most Kansas soils are naturally high in potash and do not need more. Also, wood ashes will raise the pH of our soils, often a drawback in Kansas where soils tend toward high pH anyway. Therefore, wood ashes add little benefit, and may harm, many Kansas soils. In most cases it is best to get rid of them. (Ward Upham)

Autumn is an excellent time to add organic materials and till garden soils. Winter can still be a good time to take care of this chore as long as the soil isn’t frozen. It is far wiser to till now than to wait until spring when cold, wet conditions can limit your ability to work soils easily. Working soil when it is wet destroys soil structure and results in hard clods that are very slow to break down. On the other hand, dry soil may need to be watered so it can be more easily tilled. Be sure to wait several days after watering to let soil moisture levels moderate. You want the soil moist, not wet or dry, when tilling.
 
There is a limit to how much organic material such as leaves can be added in one application. Normally, a layer 2 inches deep is adequate with 5 to 6 inches being the maximum that can be added at one time. Shredding the material before application encourages faster and more complete decomposition due to increased surface area. Remember, soil preparation is an important key to a successful garden. (Ward Upham)

Though there are high pH soils in most parts of the state, alkaline soils tend to be more common in the central and western regions of Kansas. These high pH soils can cause problems for plants by reducing the availability of certain micronutrients. For example, most Kansas soils have more than adequate amounts of iron. However, a high pH can make iron unavailable resulting in a condition called iron chlorosis. Iron chlorosis reduces the health of plants by reducing photosynthesis. Lowering the pH of such soils

Now would be a good time to have a soil test done to see if your pH is too high. If so, sulfur can be added either now or in the spring to lower the pH. Different textures of soil require different amounts. A sandy soil needs 7 pounds of sulfur per 1,000 square feet to reduce pH one point. A loam soil needs 11 pounds and clay needs 17 pounds to do the same. For example, if you wished to lower pH from 8.5 to 6.5 on a loam soil, you would need 22 pounds of sulfur per 1,000 square feet.

So, what pH do we shoot for? For most plants, a pH between 6.0 and 7.0 is preferred.

Unfortunately, adding sulfur to lower pH is not as clear-cut a solution as we would like. Here are some other factors to keep in mind.
 
Free calcium carbonate: Some soils have free calcium carbonate, actual particles of limestone mixed in the soil. These "calcareous" soils normally have a pH of 7.3 to 8.5, with 8.2 to 8.3 being most common. In order for us to lower the pH with sulfur, all free calcium carbonate must be neutralized first. A recent soil test showed 6.7 percent free calcium carbonate. One pound of sulfur is needed to neutralize three pounds of calcium carbonate. Assuming 80 pounds for a cubic foot of soil, you would need about 1.75 pounds of sulfur per square foot just to neutralize the free lime. Additional sulfur would be needed to lower pH. Adding this much sulfur to a soil at one time is not recommended.
 
Not all high pH soils are calcareous. Perform this simple test to see if your soil contains appreciable amounts of free lime. Apply one drop of vinegar to dry soil. A vigorous fizz usually means the soil contains at least 3 percent calcium carbonate. A mild fizz suggests a calcium carbonate of between 1 and 2 percent and a fizz that can only be heard suggests the soil has a calcium carbonate content less than 1 percent.

How sulfur works: Elemental sulfur does not lower pH directly. It must first be oxidized to the sulfate form with the result being sulfuric acid. The sulfuric acid produces hydrogen, which acidifies the soil and lowers pH. The oxidation takes place primarily through microbial activity.
 
Oxidation takes time: Microbial oxidation of elemental sulfur takes time and depends on:
 
- number of sulfur oxidizing bacteria present
- temperature (75-104 degrees optimum)
- moisture content of soil (too wet or too dry will slow down process)
- size of sulfur particles (the smaller the better)
 
A single sulfur application normally takes at least 2 years for most the sulfur to react and form sulfuric acid. This, of course, depends on the above factors.
 
So, what do you do about calcareous soils? See the companion article in this week’s newsletter for specific recommendations. (Ward Upham)

Iron chlorosis due to high pH soils is a significant problem in Kansas. Though Kansas soils normally contain adequate amounts of iron, a high pH makes that iron unavailable to the plant. Iron plays a major role in the production of chlorophyll. Thus, a lack of iron reduces the amount of chlorophyll and results in yellowing of leaves. Iron chlorosis weakens, and in severe cases, may kill a susceptible plant.
 
A popular recommendation for high pH soils is adding sulfur to lower pH. This works well for many soils, but not those that are calcareous.  Calcareous soils are those that contain actual particles of calcium carbonate (limestone). Calcareous soils can be difficult to practically impossible to acidify because the sulfur must neutralize all the free limestone before the pH is affected long term. In many cases you would need well over a pound of sulfur per square foot just to neutralize the free lime.
 
So, what do you do? That depends on the situation. With vegetable gardens and annual flowerbeds, work products into the soil during the time of year when there are no plants present. Oregon State University suggests mixing 5 pounds of sulfur per 100 square feet into the soil before planting. The idea is to form little pockets of acidity that result in enough iron availability for the plants during the year of application. Note that this must be done each year. Another possibility is to use iron chelates. Iron chelates hold the iron in such a way that the plant can get to it. However, not all iron chelates will work in high pH soils. For soils with a pH over 7.2, use a chelate that contains FeEDDHA (Ethylene diamine-N,N bis (2hydroxyphenylacetic acid)). This can be found in the products Sequestar 6% Iron Chelate WDG, Sequestrene 138 and Millers FerriPlus. Chelates can either be mixed into the soil at planting or sprayed on the foliage early in the season. Reapply as needed. (Ward Upham)
 
Contributors: Cheryl Boyer, Nursery Crops Specialist; Ward Upham, Extension Associate

If you plan to develop or add to your fruit garden next year, now is a good time to begin preparing the planting site. Grass areas should be tilled so grass does not compete with the fruit plants for soil moisture and nutrients. Have the soil analyzed for plant nutrients. Your local K-State Research and Extension agents have information to guide you in taking the soil sample. From that sample, the agent can provide recommendations on what and how much fertilizer to add to correct nutrient deficiencies.

​Organic materials such as compost, grass clippings, leaves, hay, straw or dried manure, can be tilled into the soil to help improve its condition. Time and weather conditions generally are more suitable in the fall than in the late winter and spring for preparing soil. If fruit plants can be set by early April, they will have developed a stronger root system to support plant growth than they would if planted later.

If there are only a few plants to be planted, consider tarping each planting area to guard against a wet spring, delaying planting after plants are shipped and received. Also, fruit tree planting can be done in the fall but plants may need to be watered during the winter if the weather is warm and dry. (Ward Upham)

October is the month that existing beds of spring-flowering bulbs such as daffodils and tulips are fertilized. If bulbs have been fertilized in the past, there is often plenty of phosphorus and potassium in the soil though it is best to take a soil test to be certain. If the soil needs phosphorus and potassium, use a complete fertilizer (such as 10-10-10, 9-9-6, etc.) at the rate of 2.5 lbs. per 100 2021 Throckmorton Plant Science Cntr. Manhattan, KS 66506 (785) 532-6173 square feet. This would equal 1 rounded teaspoon per square foot. If phosphorus and potassium are not needed, blood meal makes an excellent fertilizer. It should be applied at the rate of 2 pounds per 100 square feet or 1 teaspoon per square foot. Turf fertilizers such as a 27-3-3 or 30-3-3 can be used, but cut the rate by a third.

​If there is difficulty in determining exactly where the bulbs are planted due to the lack of foliage, fertilizing in the spring rather than the fall is acceptable. However, it is important that the plants are fertilized when the foliage first shows. Waiting until the bulbs are flowering is too late as the roots have already begun to shut down. (Ward Upham)

Many young, smooth, thin-barked trees such as honey locusts, fruit trees, ashes, oaks, maples, lindens, and willows are susceptible to sunscald and bark cracks. Sunscald normally develops on the south or southwest side of the tree during late winter. Sunny, warm winter days may heat the bark to relatively high temperatures. Research done in Georgia has shown that the southwest side of the trunk of a peach tree can be 40 degrees warmer than shaded bark. This warming action can cause a loss of cold hardiness of the bark tissue resulting in cells becoming active. These cells then become susceptible to lethal freezing when the temperature drops at night. The damaged bark tissue becomes sunken and discolored in late spring. Damaged bark will eventually crack and slough off.

​Trees often recover but need TLC — especially watering during dry weather. Applying a lightcolored tree wrap from the ground to the start of the first branches can protect recently planted trees. This should be done in October to November and removed the following March. Failure to remove the tree wrap in the spring can prove detrimental to the tree. (Ward Upham) 

We are starting to receive questions on whether it is best to cut back ornamental grasses in the fall or spring. As a rule, ornamental grasses should not be cut back while green because they need time to move the energy found in the foliage into the roots. Even when browned by cold weather, most gardeners will leave the foliage until spring because of the interest it adds to winter landscapes. Early March is the preferred time to cut back these plants. However, dry foliage is extremely flammable and should be removed in the fall from areas where it is a fire hazard.

​Another question we often receive is whether we can divide ornamental grasses in the fall. Spring is the preferred time because divisions done in the fall may not root well enough to survive the winter. (Ward Upham)

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​Though soil tests are useful for identifying nutrient deficiencies as well as soil pH, they do not tell the whole story. We often receive soils from gardeners that are having a difficult time growing crops even though the soil test shows that nothing is deficient.

Here are some factors that can affect plant growth that are not due to nutrient deficiencies or pH.

Not enough sun: Plants need a certain minimum amount of sun before they will grow well. As a general rule, flowering (and fruiting) plants need at least 6 to 8 hours of full sun per day. There are, of course, exceptions such as impatiens that bloom well in shade. Move sun-loving plants out from the shade or use plants that are better adapted to shady conditions.

Improper watering: Roots develop where conditions are best for growth. Shallow, frequent watering leads to roots developing primarily near the surface of the soil where the soil is moist. Such shallow root systems are easily damaged by heat and any interruption in the watering schedule. It is better to water less frequently and to a greater depth to encourage a deeper root system that is less sensitive to heat and water stress. Watering during the evening can also be detrimental to plants if the irrigation wets the foliage. Many diseases are encouraged by free water on the leaves. Watering late in the day often will keep the foliage wet until dew forms. Dew will keep the foliage wet until it evaporates the next morning. It is better to water early in the morning so leaves do not stay wet as long. If you must water late in the day, use drip irrigation if practical (such as in a vegetable garden).

Too much phosphorus: Most Kansas soils are naturally low in phosphorus. However, soils that have been fertilized for a number of years may have phosphorus levels that are quite high. As a matter of fact, the majority of soil tests we receive show phosphorus levels in the "high" category. Too much phosphorus can interfere with the uptake of some micronutrients such as iron, manganese and zinc. High phosphorus soils should only be fertilized with fertilizers that have relatively low amounts of phosphorus.

Poor soil physical characteristics: Roots need oxygen as much as they need water. A tight clay soil can restrict soil oxygen levels as well as make root penetration of the soil difficult. Increasing the organic matter content of clay soils can help break them up. Add a 2-inch layer of organic matter and till it in.

Walnut trees: Walnuts give off a natural herbicide that interferes with the growth of some plants such as tomatoes. Vegetable gardens should be at least 50 feet away from walnut trees if possible. For a listing of plants that are susceptible to walnut, go to: http://www.omafra.gov.on.ca/english/crops/facts/info_walnut_toxicity.htm

Tree roots: Trees not only compete with other plants for sun but also for water and nutrients. Extra water and nutrients may be needed.

Shallow soils: When new homes are built, the topsoil is often stripped off before the soils are brought to grade. Though the topsoil should be replaced, it sometimes is not or is not replaced to the same depth as it was originally. You are left with a subsoil that usually does not allow plants to grow well due to a lack of soil structure. Adding topsoil to a depth of 8 to 12 inches would be best but this often is not practical. In such cases, try to rebuild structure by adding organic matter and working it into the soil. (Ward Upham)

Contributors: Ward Upham, Extension Associate