Adding Compost to the Garden

Use caution when adding organic material to garden   

Bill Sevier: Ask a Master Gardener

Saturday, March 26, 2016

Q: Should I till compost into my garden soil to add fertilizer? What should I use? L. C., Sand Springs

A: It is almost impossible to go wrong adding organic material to any type of garden, although there are some warnings about what to use.

Organic materials contribute to the “soil tilth.” This refers to the general suitability of soil to support root growth. Tilth relates to the soil structure and presence of beneficial microorganisms, as well as the organic content. Soil needs to be loose enough to allow water and air to freely move through but also be able to hold on to enough water and nutrients for the roots to absorb them.

Sandy loam is the ideal mix of material, but often we have to deal with soils either high in sand or clay. Highly sandy soil allows water and nutrients to flow through too fast, while heavy clay slowly absorbs water and nutrients but binds them tightly when it does. Roots also have a difficult time penetrating heavy clay due to its tight structure.

Any organic material should be fully composted before added to soil. If not, the composting process will continue in the soil. When organic material decays, it uses the nutrient nitrogen (part of fertilizer) and may compete with your plants for nutrients. A work-around for this is to till in the incompletely composted material in the fall, to allow it to decay before the following spring.

Another warning about the use of organics involves the use of composted animal manures and biosolids (organic material recycled from sewage). These materials are high in salt before composting. Exposure to water percolation will eliminate it; if not, the salt can “burn” your plants. If fully composted, this is of no concern.

Composted organics are beneficial for soil tilth, and they do add essential plant nutrients. However, in manures from plant-eating animals — cows, horses, sheep and even exotics, such as elephants — the nutrient content is much smaller than most people imagine. Not only that, but the nutrients are released slowly, and it may be 1-3 years before the bulk of them are released and available to plants.

The importance of this is that plants such as fast-growing vegetables, which benefit from the addition of organics, often need more nutrients than organics are able to supply. In this situation, commercial fertilizers may be needed as well. For those wishing only to grow organically, there are some organics higher in nutrient content, such as blood, fish and cottonseed meals, milorganite, bat guano and some others. The problem with most of these is that they may not be readily available.

The bottom line is that any type of soil will benefit from most any type of well-composted organics. In vegetable and annual ornamental gardens, tilling in 2-3 inches of organics to a depth of 6-8 inches every year will optimize your plants’ growth.

For more information or to ask a question about gardening, contact the Master Gardeners at 918-746-3701 from 9 a.m.-4 p.m.

Garden tips

§  All cool-season vegetables, strawberries, asparagus and other small fruit may be planted this month.

§  Established broadleaf weeds can easily be controlled in lawns at this time with postemergent broadleaf herbicides. These herbicides are most effective in spring and fall when weeds are growing.

§  Cut down dead pine trees as soon as possible. Most of these trees died of pine wilt disease due to a nematode infection. The infection is spread by the pine sawyer beetle and dead pines are a source of infection carried by these beetles.

Dog Urine can Damage Lawns

Dog urine can significantly damage lawns

Brian Jervis: Ask a Master Gardener

Saturday, March 19, 2016

Q: I have some brown spots in my fescue lawn, which I think is due to dog urine. Is this likely and if so, what can I do about it? Irene, Tulsa.

A: Well over a third of all households have one or more dogs. This amounts to 70 million dogs in the U.S. We all love our dogs, and we benefit immensely from their companionship. However, when they urinate on our lawns, they can cause significant damage.

The damage to grass from urine is due to the high concentration of nitrogen and soluble salts. It is not related to acidity or any other chemical contents. Dealing with the issue is difficult. Dog urine damage has been much discussed — some information is factual and others are no more than urban legions.

The effect of urine on grass is similar to applying an overly-concentrated solution of fertilizer, resulting in “fertilizer burn.” The amount and type of damage depends on how much and over how big an area the urine is spread. If the urine is dilute, burning does not occur, and the spot may even eventually turn green related to the nitrogen effect. This is similar to the green clumps of grass often seen in cow pastures associated with cow urine.

Studies have shown that fescue grass is more tolerant than Bermuda, but if damage occurs, Bermuda is able to fill-in and repair itself, whereas fescue cannot.

Also, the damage seems to be greatest when the soil is dry and the grasses are not actively growing. Lawns that have been heavily fertilized also seem to be more susceptible to damage.

Female dogs and puppies tend to squat to urinate in a small space. This is much more likely to cause damage than males, who tend to spray urine over a larger area. When females urinate in a small spot, it usually results in a brown patch with a dark green halo, called “female dog spot disease” by some turfgrass experts.

Studies have shown that the only practical diet modification that may lessen damage is to make sure your dog drinks enough water. This results in a more dilute urine. There is no indication that diet modification to change the acidity of urine is useful.

To prevent damage, the obvious solution is to restrict the area or retrain your dog to use a dedicated site for urination. One thing that can be done, which is doable but not practical, is to hose down the area of urination. Studies show that if you apply water 3 times or more of the volume of urine within 8 hours of pet urination, it will prevent turfgrass kill but not the green-up effect.

It is a tough choice whether to have a pet and perhaps tolerate some damage to your lawn. However, the benefits of having a dog usually wins out over the appearance of the lawn.

For more information or to ask a question about gardening, contact the Master Gardeners at 918-746-3701 from 9 a.m.-4 p.m.

Garden tips

§  Cool-season lawns such as tall fescue, bluegrass and rye grass may be fertilized now with the first application of the season. Usually, four applications of fertilizer are required per year — in March, May, October and November, with the fall applications being the most important. Never fertilize these lawn grasses in summer.

§  If you scalp (cut very short) your Bermuda lawns now it will green up faster. However, it will also be more susceptible to weed invasion when cut short.

§  Start your routine fruit tree spray schedule prior to bud break. Contact the Master Gardener Office for a document outlining recommendations for all fruit tree types — they are not the same.

Choose Disease and Insect Resistant Plants to cope with Pests

Disease-resistant plants are beneficial in gardens

Bill Sevier: Ask a Master Gardener

Saturday, March 12, 2016

Q: What is a disease-resistant plant, and how does one find them? Ann, Tulsa

A: Anyone who has gardened in any fashion has experienced problems with various pests, including diseases, insects and the like. Diseases of plants may be caused by either fungi, bacteria, viruses or nematodes, but most diseases are caused by various types of fungi.

Gardeners and farmers cope with fungal infections three ways. First is by eliminating conditions favorable to infections such as altering methods of watering, improving air circulation and other means.

Secondly, in situations where a specific fungus may be expected, such as in plants susceptible to powdery mildew, preventative fungicides may be used. These chemicals are only preventative, at best, and will not cure an existing infection.

The third way to cope with the problems is to select plants that have been shown to have some resistance to pests. In nature, disease-resistant plants are usually due to a spontaneous change of genes in the DNA, which protects the plant from a disease. This is nature’s way of coping with threats of survival. For this random spontaneous genetic change to occur, it usually takes many years and many, many generations of plants. Once changed, there is an increased likelihood that the plant species will survive.

This beneficial spontaneous genetic change in nature can now be done in the laboratory. New technology is making it easier and faster to make precise changes to genes that produce resistance to disease. This can be done rapidly as opposed to the years it takes to let nature produce the same changes. Plants altered in the laboratory are called genetically modified or GM plants. The process to producing a disease-resistant plant in the laboratory or in nature is different, but the results are similar.

There is no one good source for information about a plant’s disease resistance. The Purdue University Extension website has one of the best lists for annuals and perennials having disease resistance.

Nurserymen carefully collect and sell cultivars of plants that have been shown to have resistance to fungi and other pests. New varieties are being introduced every year, and the nurserymen’s information about disease resistance is usually the single best source.

One should remember that resistance means the plants are less likely to get a certain disease; it does not mean it is totally protected. It still is important to alter your care of plants to make an infection less likely. It is still important to eliminate conditions that promote disease, such as avoiding overhead watering to keep water off leaves and to space plants in such a way to improve air circulation. Mulch is also important for many plants to prevent soil-born fungi from infecting, splashing from soil to leaves.

So when you decide to purchase a plant, be it tree, shrub or ornamental, be aware of what diseases it may be prone to and see if the nursery has information about resistance.

For more information or to ask a question about gardening, contact the Master Gardeners at 918-746-3701 from 9 a.m.-4 p.m.

Garden tips

§  Remove flowers from spring-blooming bulbs after blooming is completed. This will allow the plant to direct its energy into its bulb for next year's blooms, rather than producing seeds.

§  Allow foliage of these bulb plants to die and turn brown naturally before removal. As long as the leaves are green, they are storing energy for the following year.

§  These bulb's root systems become inactive after blooming and cannot absorb fertilizer. It is best to fertilize them at the time of planting, in the fall or in the spring when their leaves first emerge from the soil.

§  Divide and replant overcrowded, summer- and fall-blooming perennials. Mow or cut back old liriope (monkey grass) and other ornamental grasses before new growth begins.

Bee Keeping--Getting Started

Bee keeping is worthwhile hobby

BRIAN JERVIS: Ask a Master Gardener

Saturday, March 5, 2016

Q: I want to raise some bees. How do I get started? Sharon, Tulsa

A: It is an admirable and productive undertaking to raise bees; by some estimates, up to 80 percent of the world’s food depends directly or indirectly on bees and other pollinators.

Bees all over the world have been on the decline since 2006-07, experiencing a condition called “Colony Collapse Disorder.” This is a sudden loss of worker bees with eventual starvation of the queen and younger bees. The causes are controversial, but the consensus is that it is related to a combination of factors — parasites, viruses, insecticides and poor nutrition associated with a loss of forage. The good news is that the EPA reported recently that there was only half the amount of CCD in 2014-15 compared to 2006.

To get started as a beekeeper, or apiarist, you need to be informed. A number of books and journals are available, but a free source of basic information is a University of Missouri fact sheet — G7600, “Bee Keeping for Beginners.” This has recommendations for hives, how to acquire and where best to locate them. There is also information about sources of pollen and nectar needed for nutrition and the basics of management and harvesting of the honey.

One should also join the local and state beekeeper society for additional sources of information. They also may be a source for native bees.

To build a beehive yard, called an apiary, select an area that is close to a nectar and pollen source — either an agricultural source or abundant ornamentals. The area is best if shaded in the afternoon by deciduous trees, which cool the hives in summer and, after leaf fall, allow sun penetration in winter. It is desirable to have a nearby water source.

Hives may be built from scratch, but it is easier and not much more expensive to buy either the pre-milled parts to put together yourself or to purchase the completed hives.

It is recommended that the beginner start with two hives and expand from there as your experience and desire leads you. Bees may be purchased online or from local sources. There are several options as to the types of bees, with native bees and imported hybrids having advantages and disadvantages.

After a healthy colony in a hive has been established, the number of bees will be in the range of 75,000 with almost half of those bees being the foraging worker bees. These bees bring nectar and pollen back to the hive for honey production. A healthy hive in its second year may produce 50-100 pounds of surplus honey, leaving at least 60 pounds for the overwintering bees to feed on.

There is much more information about beekeeping than can be addressed here. Go to the above resources and get educated before starting a serious and beneficial hobby.

For more information or to ask a question about gardening, contact the Master Gardeners at 918-746-3701 from 9 a.m.-4 p.m.

Garden tips

§  If you had previous damage to the tips of pine tree limbs, especially non-native pines, it may be diplodia tip blight (a fungus) or Nantucket pine tip moth damage. Both are controlled with pesticides starting this month. Call the Master Gardener office at 918-746-3701 for recommendations.

§  Pre-emergent herbicide to control crabgrass and other summer weeds should be applied by the middle of March.

§  The pink and purple weeds blooming in many yards now is a winter weed called henbit. It is poorly responsive to standard post-emergent herbicides now. These chemicals are most effective when the weed is growing taller and before blooming. The best approach now is to mow and bag the tops to reduce seed formation. A pre-emergent herbicide next fall helps prevent the henbit from becoming established. This weed will die when it warms up.