Saturday, September 26, 2015 0 comments By: Ask A Master Gardener

How and When to Plant a Tree

Consider many factors before planting trees

Bill Sevier: Ask a Master Gardener

Saturday, September 26, 2015

Q: Which trees are best planted in fall and which in spring? P.M., Tulsa
A: When you plant a tree, it potentially will be with you the rest of your life, so it is best to make all the correct decisions about the what, when and how part of the process.
Trees and shrubs coming from the nursery are either balled and burlapped, container-grown or have bare roots. They may be deciduous or evergreen.
Fall is by far the best time to plant container-grown, as well as most balled and burlapped trees and shrubs. However, bare-rooted and evergreen plants should be planted in spring. Bare-rooted plants must grow new roots to survive, and new roots are stimulated by buds opening in spring. Evergreen plants lose water in winter and, if planted in fall, do not usually have enough root system to support their water needs.
Trees planted in fall have been shown to outperform those planted in spring by a significant margin. Trees planted then will have fall, a large part of winter and the following spring to develop a more extensive root system in preparation for the following growing season.
When selecting a tree, consider not only the visual appeal, but also the growing requirements (sun or shade, soil type), mature height and spread, and nuisance factors. Some trees have undesirable seed production and pest susceptibilities. Always think of the mature height of the tree if it will be close to power lines or buildings. Another useful suggestion is to get the largest tree you can afford and can plant yourself.
OSU has a fact sheet, F-6414 “Planting Trees and Shrubs,” which has detailed information for a guide. The basics, as outlined in the fact sheet, are:

  1. Look for soil drainage problems and correct them.
  2. Perform a soil test to determine fertility and acidity status.
  3. Dig a hole 2 to 3 times as wide as the root ball, but no deeper than the root ball itself.
  4. In clay soil, plant the tree 2 to 4 inches above grade to help with drainage.
  5. Use no amendments in the backfill soil.
  6. Mulch with 2 to 4 inches of loose organic matter. Do not put plastic under the mulch.
  7. Keep a several-foot-wide grass-free circle around young trees for two years.
  8. Do not prune back the top of the tree or any branches on the trunk unless damaged.
  9. Fertilize trees and shrubs on the soil surface only if needed by soil test. Then use only nutrients needed.
  10. Stake only if needed due to the tree’s structure or if it is on a slope or windy area. Then do so for only one growing season.
  11. Maples, ash and other young trees may sun scald in winter if not wrapped. Wrap trunks in fall and  remove in spring.
Proper selection and planting of trees will add beauty to your landscape, as well as supply shade and shelter for you and the next generation.

Garden tips
§  Begin preparing your outdoor plants for a move indoors. Move houseplants indoors when the outside and indoor temperatures are about the same. For plants in full sun, move to shade. Begin with light and then heavier shade over a week’s time to prepare the plant for the low light indoors. If you move the plant from full sun to a low light indoor situation, the plant may experience “shock”, lose leaves and perform poorly inside.
§  Inspect plants for insects and disease and treat accordingly. In many cases, a few insects can be controlled by hosing down the plant and removing by hand. Another option is to use an insecticidal soap spray. This is effective and safe for you and your plant.
§  Also consider drenching the soil with 2-3 pot volumes of water to help remove insects and residual fertilizer salts.
'Ask a Master Gardener'

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Saturday, September 19, 2015 0 comments By: Ask A Master Gardener

Crapemyrtle Bark Scale, a New Pest

Bark scale insects can infest crapemyrtles

Brian Jervis: Ask a Master Gardener

Saturday, September 19, 2015

Q: My crapemyrtle tree has some type of insect on the trunk. They look to be covered with cotton. What is this? T. R., Tulsa

A: Insect pests continue to surprise us. As we learn to deal with the old ones, we are faced with new arrivals. This one comes from crapemyrtle’s region of origin, Asia, and is called crapemyrtle bark scale (CMBS). It was first discovered in the U.S. in central Texas in 2004 from where it spread northward.

Master Gardeners are now seeing it regularly in their office. Most of CMBS seems to have been spread by nursery stock and on plants purchased in one area and used in another. The female scales cannot fly.

Like other scales, the life cycle begins with either the female scale or eggs overwintering on the crapemyrtle under loose bark. When the eggs hatch, small mobile “crawlers” are produced, which migrate on the plant and may be spread to other crapemyrtles by wind or birds. These crawlers mature into adults. There may be 2-3 generations produced per year depending on the temperatures.

Once the female is fully developed, she mates and attaches to the stems and trunks of the crapemyrtle where she remains fixed and lays eggs for the next generation. She dies shortly thereafter, but the eggs survive under her covering until they hatch.

As the scales feed, they release a liquid, called “honeydew.” This is similar to the behavior of aphids. The sugars in honeydew may support the growth of a fungus called “sooty mold.” This overgrowth produces large black patches on the bark of the crapemyrtle, which is not significant in terms of the plant’s health.

This pest is easy to identify because it is the only scale insect to infest crapemyrtles. The adult female is usually about 2mm long and has a distinctive gray-white felt-like covering. When one of the females is crushed, a pink blood-like fluid is released.

Treatment strategies for this insect are still being evaluated. One nonchemical approach is to scrub down the trunk of the crapemyrtle with a mild solution of dishwashing soap and water using a long-handled brush to remove scale and sooty mold.

Summer horticultural oils recommended for other scales are not thought to be useful, but using heavier dormant oils applied to the trunks in late winter may be effective.

Systemic insecticides when applied as a drench to the plant’s root zone may offer the best control. The insecticide chemicals shown to be effective are imidacloprid, thiomethoxam and dinotefuran. These generics are sold under several brand names. They should be applied between May and July as it takes a few weeks for the chemicals to be absorbed into the plant’s vascular system and before protection will start.

For more information, go to OSU’s Pest E-alert website for an excellent discussion.

Garden tips

Watch for fall specials at garden centers and nurseries because fall is a great time for planting many ornamentals. Choose spring flowering bulbs as soon as available.

Fertilize established fescue lawns with one pound of actual nitrogen fertilizer per 1000 square feet now and again in November. Do not fertilize Bermuda or zoysia lawns until next spring. Late fertilization of these warm season grasses may promote disease.

Winter broadleaf weeds like dandelion will begin to emerge in late September, which is also the best time to control them with a 2, 4-D type herbicide.

September and early October is garlic planting time with an aim for harvest in June of next year. There are many varieties from which to choose. OSU suggests German Red, Inchilium Red, Silverskin and Spanish Roja for varieties that do well in our are

Saturday, September 12, 2015 0 comments By: Ask A Master Gardener

Monarch Butterflies Life Cycle

Master Gardener: Monarch butterflies depend on milkweed plants

Bill Sevier: Ask a Master Gardener

Saturday, September 12, 2015

Q: I have some milkweed, which has both small eggs and caterpillars of monarchs. How long does it take for the eggs to hatch and the caterpillar to become a butterfly? T.W., Tulsa

A: numbers of monarch butterflies and their dependence on milkweed plants has inspired many people to become actively involved in their support.

The monarch’s life cycle and migration are uniquely amazing. There are two groups of monarchs in the U.S. — Western and Eastern. The Western group remains in California. The larger group of Eastern monarchs overwinter in Mexico and migrate mostly up through the Midwest. They may fly over 3000 miles and as far north as Canada.

The monarch’s migration typically involves four remarkable generations, each of which goes through four stages of development — egg, larva (caterpillar), pupa (chrysalis) and then adulthood. The time from when the egg is laid to an adult butterfly is about four weeks. All of the development times quoted are dependent on the environment, especially the temperature.

The eastern monarch populations leave their overwintering area in Mexico in February and March, flying northward. They soon mate and deposit eggs on milkweed plants. The eggs hatch in four to five days, and the larvae (caterpillars) eat large amounts of milkweed leaves and mature in about two weeks. At that time, they turn into a pupa.

The pupa hangs upside down using a silk attachment, called a chrysalis. Inside the chrysalis, the caterpillar changes into a mature butterfly, which emerges in about 10 days. This adult will be ready to mate in a few days.

A second generation of monarch butterflies is produced on their northward journey in May and June. This generation lives about two to six weeks. They lay eggs and produce a third generation in July and August as they continue to feed on flower nectar and migrate to their summering home in the Midwest or as far north as Canada. This generation, too, lives about two to six weeks and is responsible for producing a fourth generation in September and October.

The fourth generation is unique. They may live for six to eight months. These monarchs migrate back to a warmer climate in either Mexico or California, where they overwinter until the following spring. After overwintering, they start northward and serve as the parents for the next yearly migration cycle in spring.

This is a remarkable story of these beautiful butterflies, which we often take for granted. We can do several things to help lessen their decline, one of which is to plant milkweed. For a list of milkweeds that are native to Oklahoma and the region in the state where found, go to the Master Gardener website and look for “Monarchs and Milkweed” under the “Tips and Techniques” section.

Garden tips

It is time to divide and replant spring-blooming perennials like iris, peonies and daylilies, if needed.

In fall, strawberry plants build up food reserves and form fruit buds for the next year’s crop. They should be fertilized between mid-August and mid-September with a nitrogen fertilizer such as ammonium sulfate at a rate of 1.5 pounds per 100-foot row. Apply 1 inch of water if no rain is expected.

You have all of September to plant cool-season vegetables like spinach, leaf lettuce, mustard and radishes and until the middle of September to plant rutabagas, Swiss chard, garlic and turnips
Saturday, September 5, 2015 0 comments By: Ask A Master Gardener

Fall Reseeding of Tall Fescue

Fescue lawns benefit from fall reseeding

Brian Jervis: Ask a Master Gardener

Saturday, September 5, 2015 1

Q: A large area of my fescue has died and needs to be reseeded. This happened in spite of a lot of rain. Can this be prevented? How do I reseed? Troy, Tulsa

A: The loss of tall fescue turfgrass in summer is a recurring event for most people. It is worse with hot and dry summers but can occur with excessive rain as well. Normally fescue can briefly take standing water, but when the ground is saturated, oxygen is forced out and the roots suffocate. Then along comes the stress of heat, which fescue tolerates poorly. This combination of events can kill fescue. Another threat to fescue comes from a common fungus called “brown patch,” which is destructive.

After this series of events in summer, it is time to reseed in fall, ideally from mid-September through mid-October. Reseeding of fescue can be done either in spring or fall, but the spring-seeded grass usually dies in summer due to the lack of root development. Grasses seeded in fall have a more mature root system to withstand the following summer.

As far as how to reseed, there are several steps involved. Detailed information is available in the Master Gardener’s office in Tulsa or online.

Seed selection is an important decision — both the type of seed and the quality. Remember with seeds you get what you pay for — buy high-quality weed-free seeds. OSU feels there are many good fescue varieties and no one variety is “best.” It recommends using a blend of three or more types of fescues alone or mixed in with bluegrass, another cool-season grass. Mixed with fescue, the two grasses seem to compensate for each other’s weaknesses.

To minimize loss of fescue next summer, obtain the Master Gardeners’ information sheets on lawn care and follow recommendations about watering, fertilization and mowing.

Steps for reseeding fescue Lawns
1. For existing lawns, identify and correct factors causing poor performance. Start with a soil test to see what nutrients and soil acidity corrections may be needed.
2. Make a decision as to what type of seed you wish to plant and purchase beforehand.
3. Buy a “starter” fertilizer, best based on soil test. Use only nutrients needed. Do not use phosphorus containing fertilizer unless a soil test indicates a need.
4. Remove undesirable grasses and weeds
5. Loosen the soil by hand or machine, adding fertilizer and organic compost as needed. This is important, as all soils have a crust which should be broken for seeds to thrive.
6. Sow the proper amount of seed to get good coverage, avoid excess seeding. More is not better.
7. Irrigate as needed to keep top of soil constantly moist until seedlings are 2 inches tall.
8. Irrigate less often and more deeply at 2 inches to establish deep roots.
9. Mow with a sharp bladed mower when 3 inches tall.
10. If needed, control broadleaved weeds with a 2,4-D type herbicide after third mowing.
Garden tips
Fall webworms are now prevalent. These are the dense webs one sees on the limb tips of some trees, especially pecans. The caterpillars remain within the webs to feed on leaves, expanding as new leaves are needed. Control can be as simple as pruning out, if the tree size permits. Insecticides can be helpful, but most people tolerate the infestation, realizing the damage is mostly aesthetic and the tree will survive quite well. If an insecticide is used, consider an organic product called Bacillus thuringiensis, or Bt. It is safe for you, your pets and the environment.

Now is a good time to submit a soil sample to the OSU Extension office for testing. Do this before reseeding fescue or creating a garden bed this fall. Call the Master Gardener office at 918-746-3701 for instructions.

Tall fescue should be mowed at 3 inches and up to 3½ inches if it grows under heavier shade. Don’t fertilize fescue lawns until it cools later this month, then fertilize again in November.