Hoop Houses Extend Growing Season

Get head start on spring growing with hoop houses

Bill Sevier Ask a Master Gardener

Saturday, December 31, 2016

Q: I am interested in a hoop house. How do I get started? J.M., Tulsa

A: First, go to the OSU Tulsa Master Gardener website, tulsamastergardeners.org, and look under “Tips and Techniques.” Master Gardener Gary Sanders has written instructions for an easily constructed small hoop house.

Hoop houses, also called high tunnels, have many different designs and uses; some are built on a large scale for commercial growers of vegetables and cut flowers; much smaller ones are used by homeowners. OSU has a fact sheet about high tunnels, HLA-6720, “High Tunnels,” which has a great deal of practical information about construction and management.

Hoop houses basically consist of bowed hoops, or arches, formed from various materials such as PVC or other types of bendable plastic pipe. The ends of the hoop are fixed either to a raised bed frame or anchored in the ground over a bed. The house is then covered with translucent plastic greenhouse film secured to the hoops and garden bed. The ends and sides are generally created in such a way that they may be opened up for ventilation when needed.

Hoop houses should be located in full sun and close to a water source. The location should have some wind protection; the plastic covers are susceptible to wind damage. Drip irrigation, which can easily and cheaply be installed, is ideal for this situation. The planting area is best if it is a raised bed, either a simple mounded bed of soil or one constructed of a wood frame. In any case, it should have good soil, high in organic material that drains well.

Hoop houses can give you a head start in spring for your cool-season vegetables or for growing sprouts. In fall, the same cool-season vegetables will produce deeply into winter. Some of the cool-season vegetables that may be grown include cabbage, cauliflower, collards, kale, broccoli, Swiss chard, lettuce, onion, radish, spinach and turnip.

A hoop house will also extend the growing season of warm-season vegetables like tomatoes.

It is estimated that a hoop house extends the frost-free growing season by as much as two months. If you place a second layer of plastic or a row cover fabric directly over the plants, the growing season for some vegetables can be extended throughout the winter.

Hoop houses do require regular care. Heat is collected from the sun shining through the plastic, and when too high, the ends of the house must be opened to allow the wind to cool the plants. In summer, when the temperature outside is above 90 degrees, a shade cloth should be placed over the house for additional cooling.

Consider building a hoop house, it is an easily constructed and useful project which is surprisingly productive.

Garden tips

• Any green weed in dormant (brown) Bermuda lawns may now be sprayed with glyphosate, found in Roundup and many others. This will kill anything green but will not hurt the Bermuda. Glyphosate cannot be used on dormant zoysia grass or tall fescue lawns at any time.

• Control overwintering insects on deciduous trees or shrubs with horticultural oil sprays in dormant concentrations; applied when the temperature is above 40 degrees in late fall and winter. Do not use “dormant” oils on evergreens.

• Inspect your irrigation system and replace worn or broken parts.

• Shelled or unshelled pecans should be stored in an airtight plastic bag or container in the freezer. Care should be taken that they are dried beforehand.

Options for Disposal of Christmas Trees

Repurposing Christmas trees benefits environment

Brian Jervis: Ask a Master Gardener

Saturday, December 24, 2016

Q: Can my Christmas tree be placed curbside with my trash for city pick-up? R.M., Tulsa

A: Yes, the city of Tulsa will take your Christmas tree, along with your trash on your regular pick-up day. They do recommend the tree be 6 feet in length or less and suggest cutting it up, if your tree is longer.

However, there are several other options for your tree that are more environmentally friendly than sending them to the trash to be burned.

They may be used for a bird shelter, mulch for your garden beds, submerged in a fishing hole, shredded, or taken to the Tulsa Green Waste site.

Trees may be shredded into mulch in a couple of ways. All of these methods involve removing all tinsel and other decorations beforehand.

First, Southwood Landscape and Garden Center, 9025 S. Lewis Ave., and Owasso Tree and Berry Farm will take live-cut trees and recycle them for either mulch or fish shelters. You need not have bought your tree from these businesses for them to accept it.

Another way to recycle your tree, if you are able, is to take it to the city of Tulsa’s Green Waste Site. It is located at 2100 N. 145th East Ave. and is open seven days a week from 7:30 a.m. to 5 p.m., closing only on city holidays. The service is free with proof of Tulsa residency. At the green waste site, you may also obtain all of the free woodchip mulch you may need. In addition, free firewood is available.

Birds need sanctuaries from the cold and predators in winter. Christmas trees near a feeder offer a great refuge until spring and trees begin leafing out. You can also help them out by placing treats such as peanut butter and suet on the limbs for a high energy source. This would be an interesting project for a child.

Recycled Christmas trees also work well submerged into a lake or pond as a fish shelter. These piles of trees are productive for certain types of fish. This is especially true for attracting crappie.

The smaller limbs and fronds can be removed and be placed in the garden bed as a green mulch. After removing the limbs, the remaining trunk can be used as a stake in the garden. The limbs used as mulch will decay over time, and you will reap not only the benefits of a mulch, but also the nutrients they release onto the soil.

These limbs also may be added to your compost pile as a source of green material to help balance the brown material such as leaves. Green (nitrogen source) and brown (carbon source) are needed by the microbes that break down the material. For those new to composting, OSU has an informative fact sheet, HLA-6448, “Backyard Composting in Oklahoma,” available with an online search or from the OSU Tulsa Master Gardeners website.

Garden tips

§  Don’t forget to keep the compost pile watered. The decay process to produce garden-friendly compost continues in winter if the pile is large enough and kept watered and turned.

§  Cover strawberry plants with a mulch about 3-4 inches thick if plants are prone to winter injury.

§  Wait to prune fruit trees until late February or March.

§  Wilting and drooping of leaves on evergreen trees and shrubs is common when the temperatures drop low. This is a way pla

Be Careful When Using Fireplace Ashes in the Garden

Fireplace ashes can harm gardens

Bill Sevier: Ask a Master Gardener

Saturday, December 17, 2016

Q: Is it OK to spread my fireplace ashes over my vegetable garden every winter? N.G., Sand Springs.

A: The best answer is “probably not.” Ashes from burning various types of wood have a unique chemistry, which might be useful in some situations but are not recommended for vegetable and ornamental gardens or for lawns, with few exceptions.

The problem with ashes is three-fold, two of them significant. One is that the pH is high. The pH is a measurement of level of acidity on a scale of 0 to 14, with 7 being neutral, 0 very acid and 14 extremely alkaline. Examples of the pH of some items are: Battery acid pH of 0, lemon juice pH of 2, pure distilled water pH of 7, baking soda pH of 9 and household bleach has a pH of 12-13.

The pH range of fireplace ashes has an average value of 11.6, right up there with household bleach. Added to soil, it removes acid, driving the pH value up and out of the range of acidity that most plants prefer.

Most vegetables and lawn grass perform best in slightly acidic soil of an average pH range of 5.8 to 6.5. Many shrubs need even lower pH values. Azaleas, blueberries and gardenias need an acidic pH of 5 to 5.5. Other acid-loving shrubs include most conifers, camellias and hollies.

When the soil is out of the pH range needed by a particular plant, it cannot absorb nutrients, such as iron. This is the reason for yellow leaves on many azaleas growing in soil that has become too alkaline, producing yellow leaves that have a distinctive pattern called iron chlorosis.

Another downside to using fireplace ashes is the amount of salt. Excess salt in soil will predictably kill plant roots. An example of this is seen with the use of salt on roadways in winter with subsequent death of roadside plants the following spring. Once the salt is in the soil, it may take a long time for correction to occur.

The last concern about fireplace ashes is the amount of potassium. There is about 6 percent potassium in ashes, and they will add this nutrient to soils, which if deficient, could be helpful. However, the results of soil tests of Tulsa-area gardens by OSU show that in previously fertilized soils, the majority have adequate or excessive potassium.

OSU has a fact sheet “Fireplaces Ashes for Lawn and Garden Use,” which offers a good summary of chemical content of various ashes from burning different hardwoods. The fact sheet recommends that if ash is used, one should use no more than 10 gallons per 1,000 square feet in sandy soils and 20 gallons for the same area in other soil types. The key take-home fact from this document is that if you apply ashes to your soil as outlined above, you should do so no more often than once every 10 years.

Garden tips

§  All birds need and appreciate clean feeders and unfrozen water on cold days. Place feeders close to protective shelter, if possible.

§  Select a freshly cut Christmas tree. Make a new cut prior to placing in tree stand. Add water daily.

§  Light prunings of evergreens can be used for holiday decorations. Be careful with sap that can mar surfaces.

§  With the warmer weather, newly seeded fescue will continue to grow roots and make energy if you keep them free of leaves.

Planning a Vegetable Garden

A Vegetable Garden Requires Planning

Brian Jervis: Ask a Master Gardener

Saturday, December 10, 2016

Q:I am thinking of planting a vegetable garden this spring. I am not sure how to get started, can you help? T.M., Sand Springs

A:Vegetable gardens are enjoyable and productive for most gardeners, but the key to success is in the planning. Planning for both the proper location, choices of vegetables and times to plant.

The OSU Tulsa Master Gardener’s web site has good information to help you. Go to the vegetable section and review OSU fact sheet, # 6004, “Oklahoma Garden Planning Guide”. This fact sheet has the how, when and where of starting a vegetable garden. Most all of the vegetables grown in Oklahoma are listed with dates as to when they should be planted, whether to use seeds or transplants and days to harvest. Other fact sheets in this section list the varieties of vegetables which grow best in our area.

Location is key. Most vegetables grow best in full sun although some of the cool season vegetables (cabbages, lettuce and others) will tolerate some shade. A north-south orientation of the rows will maximize sun exposure.

It is best to have a garden near you and near a source of water. The closer it is located, the more likely you will visit the garden and deal with problems early.

If you have good soil you are fortunate. When soils have too much sand or clay there are two ways to improve them. One is to till in large amounts of fully composted organic material. This will help sandy soils retain water and nutrients and aid heavy clays to more easily drain and to allow root penetration.

The other option for problematic soils is to plant in raised beds. With raised beds you should import good soil which bypasses the problem with native soils. Raised beds may simply be mounds of good soil without a containing structure, or better, construct a container out of wood, stone or other material.

A related option to raised beds is to plant in containers. It is surprising how productive a pot on the patio can be. Many vegetables grow well with this method. In addition, they may be moved about to deal with sun and shade.

It is best to perform a soil test at the start to decide what nutrients are needed when selecting fertilizers. Helpful information about how to fertilize vegetable gardens may be found on the Master Gardener web site.

Most all vegetables will also need mulching to conserve moisture, prevent weeds and help to moderate the soil temperature. Any mulch is OK, there is no “best” mulch.

Remember, all gardens will have some insect or disease issues in the course of the growing season. Regular inspection will identify problems early so they may be dealt with more easily. The OSU Master Gardeners can help with all of these problems by calling our helpline at 918-746-3701, M-F, 9am to 4pm; or come by the office at 4116 E. 16^th street, gate # 6 into the Tulsa Fair Grounds.

Garden Tips

Firewood information may be found in OSU Fact Sheet NREM-9440. This fact sheet outlines which types of wood burn best and also describes how to obtain and measure wood. Tips on how to cut and split wood safely are also described.

One thing you should not do, when obtaining firewood, is to transport it any significant distance. Because of the high incidence of many types of invasive insects in firewood, such as the Emerald Ash Borer, many states ban all imported firewood. A good rule of thumb is to not go over 50 miles to obtain wood; 10 miles is even better.

Selecting and Caring for a Christmas Tree

Choosing the perfect Christmas tree

Bill Sevier: Ask a Master Gardener

Saturday, December 3, 2016

Q: I am going to get either a live-cut Christmas tree or a live tree with roots to plant in my yard later. Which would be best? S.J., Tulsa

A: It seems that more and more people are opting for artificial Christmas trees, and they certainly have advantages in terms of cost savings. Storage, assembling and disassembling, are downsides.

Many feel that having a live tree is more in keeping with the Christmas spirit, this is especially true for older people for whom a live tree was the only option in their youth.

Live trees may come with their roots in pots or balled and burlapped to be planted later, or freshly cut, to be disposed of after Christmas.

OSU suggests that a live tree purchased for later planting be kept in an unheated and shaded area until brought inside. They should be watered regularly and planted soon after the holiday. It is best to minimize indoor time to a week.

Live-cut trees may be bought from a local vendor or you may go to one of about 15 Christmas tree farms, mostly in northeast Oklahoma, and cut your own. Look for the Oklahoma Christmas Tree Association website for details.

Many of the precut trees in local markets were shipped in from the northwest. They may be drying after having been cut for a few weeks. Dry trees lose needles and are fire hazards.

To help people pick out a fresh and good quality live-cut tree, OSU has published a list of recommendations to consider in the selection process, a summary of which is below:

• Tug the needles and bounce the butt on the ground. If green needles fall, consider another tree.

• Look for fresh green color. Some trees are sprayed with a blue-green dye to cover brown needles. Break some needles, they should be flexible and moist.

• Buy early before the desirable trees are sold.

• Fir and pine trees hold needles better than spruce trees.

• Be sure limbs are stout enough and located in such a way not only to produce a nice shape, but also to be able to support your decorations.

• Ask the dealer if the trees were locally grown or imported. Local trees are more likely to be fresh.

After selecting your live-cut tree, OSU has some suggestions for care to keep it fresh through the holidays:

• After purchase, cut an inch off the butt and immediately immerse it in plain water. No need for any additives to the water.

• Keep the tree in a cool shady area in water if there is a delay in bringing it indoors.

• Trees need a sturdy stand with lots of water; a tree may absorb a quart of water per day, so keep the reservoir full.

• Keep the tree away from heat sources such as fireplaces and air ducts. Never have an open flame near a tree.

If you follow these sensible recommendations, your tree should be safe and easily last for a few weeks, bringing a delightful addition to the holiday season.

Garden tips

• Proper care will extend the life of Poinsettias through the holiday season and beyond. Keep in the brightest light possible and away from cold windows and heating vents. They prefer a room temperature of 65-75 degrees. They will die or perform poorly with too much or too little water. When the top inch or so of the potting soil is dry, add lukewarm water until it emerges from the bottom of the pot. Discard this water. There is no need for fertilizer.

• If your roses have not been mulched, do so now. This is a good place to use those fall leaves that have been shredded with a mulching mower. Mulch not only will prevent cold damage to those susceptible plants but will keep soils from warming on warm winter days, breaking dormancy.

Use and Misuse of Gypsum and Lime

Never use gypsum, lime without prior research

Brian Jervis: Master Gardener

Saturday, November 26, 2016 12:00 am

Q: When is it best to apply gypsum and lime to my lawn? D. A. Tulsa

A: You should never use either one without specifically documenting a reason. Gypsum has been used in the past to improve the drainage of clay soils, and lime is used to treat overly acidic soils.

Gypsum is calcium sulfate and was once thought to be able to loosen heavy clay soils. Science-based studies have shown this not to be true.

Clay particles are so small and flat they pack down and present a barrier to water, nutrients and plant roots. Tactics to loosen these soils have been researched thoroughly and gypsum, along with other materials, has been shown not to be useful. The OSU handbook, E-1003, “Oklahoma Homeowner’s Handbook for Soil and Nutrient Management,” explains the origin of the gypsum myth.

Gypsum is appropriate to treat soils with calcium or sulphur deficiency, but this is not likely in our area. Gypsum is also useful to treat “sodic” soils, or soils that have been exposed to excessive amounts of sodium containing salts. These soils need to have the salts removed to be plant friendly. The calcium in gypsum will displace and correct the salt excess.

The ideal approach in dealing with heavy clay soils is to use raised beds. If raised beds are not an option, regularly tilling large amounts of organic material will improve the tilth of clay soils as it does with all other soil types.

The use of lime is useful but should always be based on the pH (measurement of the level of acidity) result of a soil test.

Lime, which is calcium carbonate, will raise the pH in soils, making it less acidic. The pH of soil is a result of several factors, one of which is the amount of rainfall. Rain filtering through soils tends to remove calcium and add hydrogen. Hydrogen in soil increases acidity; calcium reduces it. The more rainfall, the more likely the soil will be acidic.

Often people who are from states east of us will assume liming is needed regularly, as it was often needed there, but that is not the case in most of Oklahoma.

Average yearly rainfall in Oklahoma drops steadily from our eastern border to the panhandle. Because of this, on average, there is less soil acidity from east to west.

Most plants perform best in neutral to slightly acidic soil; this includes most turf grasses. According to the USDA, the optimum pH for fescue and Bermuda is acidic, in the range of 5.5 to 7.0. Our average pH in the Tulsa area, based on more than 1,000 soil test results performed by OSU is 6.8, which is favorable to turfgrass and other plants. So, on average, no lime is needed and if used might be harmful to your grass. A soil test will inform you of a need for lime.

Garden tips

§  Fertilize cool-season grasses like fescue with 1 pound nitrogen per 1000 square feet. This should be the last fertilization for fescue until next spring. Do not fertilize Bermuda or Zoysia until green-up next April.

§  Spring-flowering bulbs like hyacinth, narcissus and tulip, which are sold for “forcing,” can be potted indoors for a colorful winter display.

§  Tulips can still be planted outdoors through this month.

Options for Leaf Use in FAll

Fallen leaves can be asset to gardens

Bill Sevier: Ask a Master Gardener

Saturday, November 19, 2016

Q: What is the best way to dispose of leaves in fall? I would rather not put them in the trash. Andy B., Tulsa

A: There are much better options for leaf use than placing them on the curbside for trash pickup. There are several ways fall leaves may be an asset for your garden. They may be used for mulch, tilled into garden soil for organic enrichment, composted or simply mowed into the lawn. All of these options ultimately give you free fertilizer, mulch and compost.

Most of these options involve the use of a lawn mower, preferably a “mulching” mower. This reduces the size of a leaf pile about 10-fold and helps accelerate the ultimate decay and release of nutrients.

University-based studies have shown that mowing up to 6 inches of leaves into the lawn is not only safe, but also beneficial for all types of turfgrass if done properly. The lawn should be mowed tall (2-3 inches), and the leaves should be completely shredded so they fall below the top of the grass. There, they decompose rapidly, add nutrients and do not contribute to thatch or disease.

Leaves also make great mulch for your garden, especially if shredded with a mulching mower. Shredded leaves added to your garden beds in the fall should completely decompose into usable organics and nutrients by the following fall, ready for another application. If they are not shredded and simply piled up in the bed, they may become soggy, decompose more slowly and prevent adequate passage of water and air.

The myth that some leaves, especially oak leaves, may add acidity to your soil, is simply not true. Good studies have shown that most all of the standard mulches have no effect on soil pH, but they all do add nutrients.

These same shredded leaves also may be directly tilled into the soils of your garden beds this fall. If added to the soil in fall, they will compost, and the bed should be ready by spring for planting of either vegetables or ornamentals. If the leaves are tilled into the garden in spring, rather than fall, they may compete with your plants for nutrients until decomposed.

It is highly desirable to have a compost pile for garden wastes. Leaves and most other yard wastes may be changed into a valuable garden addition. To get started, OSU has a fact sheet, “Backyard Composting in Oklahoma,” which offers complete information on compost bins and what may and may not be composted. This is available on the OSU Tulsa Master Gardeners website, tulsamastergardeners.org.

Don’t forget that Tulsa has an excellent free green-waste site, 2100 N. 145th E. Ave., for yard wastes, including large tree parts. The site is open daily, except city holidays, and is free to Tulsans with a proof of residence. There, all your yard wastes, including leaves, will be shredded into mulch for all. This service is free, and you may also get free mulch, as much as you want.

Garden tips

• Remove all debris from the vegetable and flower garden to prevent overwintering of various garden pests.

• Start new garden bed preparations now. Till plenty of organic material into the soil in preparation for spring planting.

• Cover water gardens with bird netting to catch dropping leaves. Take tropical water garden plants indoors and stop feeding fish when water temperatures near 50 degrees.

Fall Clean-up is Important to Prepare for Spring

Fall clean-up will Benefit spring planting

Brian Jervis: Master Gardener

Saturday, November 5, 2016

Q: Should I cut the tops off of my lilies in fall or wait until spring? T.C., Owasso

A: Both times are acceptable, and what you do depends basically on the appearance you are striving for in your landscape. This brings up the topic of fall activities in the garden that may help increase the performance of ornamentals and vegetables the following spring.

The option of removing leaves and stems of perennials applies to many plants other than lilies. Generally, it is best to leave perennial leaves attached to the plant as long as any parts are green. When green is present, the plant is still making energy and storing it in roots or bulbs.

One of the exceptions to removal of all plant parts from perennial ornamentals is when one wishes to save seeds for birds. Plants like purple coneflower have heads loaded with seeds that the birds can eat over the winter.

Lilies have long leaves that if left in place after browning and falling over, serve as a type of mulch to conserve water and moderate ground temperature. Also, if left in place, they may be pulled by hand or raked, as they are easily detached in spring. If for appearance sake you wish to remove the leaves in fall, it is best to mulch the lilies for the winter after the first frost.

Recommendations for fall cleanup in the vegetable garden is the same for ornamentals.

The tops of perennials such as asparagus should be handled like lilies. Annuals such as tomatoes and members of the squash family will develop disease and insect problems in the course of the growing season.

Many of these plants will harbor disease-causing microbes and also various overwintering insects and eggs in the material left behind after harvest. If left in place, the disease and insect numbers will build up and increase in severity from year to year.

So for vegetable gardens, it is best to remove all of the debris from last summer’s crop. After removing the debris, it helps to till the garden to expose any undesirable microbes or insects to the effects of winter.

Also, the fall is a good time to till organic material into your garden. Any composted organic supplements will benefit the soil when added in spring or fall. Even though some of the organics, such as leaves, might not be fully composted when added in fall, they should decompose over winter and be good to go in the spring. Some gardeners also will plant winter-hardy cover crops such as Austrian winter peas and winter rye. These cover crops protect the garden soil, and when tilled into the spring garden, they add desirable nutrients and organics to the garden.

Other suggestions for your garden beds is to obtain a soil test. This will give you sound advice about what fertilizers and amendments to add to the garden in fall and in springtime.

Garden tips

§  Leftover garden seeds can be stored in an airtight container in the refrigerator or freezer until next planting season. Discard seeds more than 3 years old.

§  The garden centers still have large selections of spring-blooming bulbs for sale. If you intend to plant bulbs, buy them and plant soon. Tulips can still be successfully planted through November.

§  Be sure to keep leaves off newly seeded fescue. The sprouts will die without sun and air exposure.

Emerald Ash Borer a Threat to All Ash Trees

Spread of Emerald Ash Borer puts area ash trees at risk

Bill Sevier: Ask a Master Gardener

Saturday, October 29, 2016

Q: My friends in Michigan say they are losing their ash trees to an insect. Is my tree at risk here in Tulsa? Jim, Tulsa.

A: Your ash tree is not at risk yet but may very well be in the near future due to an insect called the Emerald Ash Borer.

This insect, like so many of the insects and diseases that have devastated trees in the U.S., is an import from Asia. This has the same potential for destruction of all varieties of our ash trees, as did the imported diseases that killed our elms and American chestnuts.

The Emerald Ash Borer was first seen near Detroit in 2002 and has been noted to spread initially eastward then onto states south and west. Until recently, it had been found in all surrounding states but not in Oklahoma. Recently, it has been reported in the northeastern part of the state and can only be expected to spread. The borer often is transported to new areas by firewood and nursery stock.

The insect is said to cause the death of many millions of ashes in the heavily involved states, and that potential exists for all our ash trees.

The borer adults are metallic green and about ½-inch long. The adults do little damage, but their larva bore into the outer layer of ash trees, where they feed and slowly block the circulation of the tree. Trees initially experience dieback of the uppermost part of the canopy, which spreads to involve the whole tree. Trees often have stress-induced secondary shoot growth on trunks and at the tree’s base.

Studies looking at ways to prevent infestation and to treat those trees already involved have shown there are effective controls, but they are most effective when used for prevention. Trees with borers may benefit from treatment at early stages of involvement, but most likely those trees with dead tops will die over the next few years.

The effective insecticides are all “systemic,” which means they must enter the tree’s circulation. This is done as a soil drench over the root zones; by injection directly into the tree, or spraying directly on the tree’s trunk. Injections must be done by an arborist, but drench and trunk spraying can be done by homeowners.

The big question involves which trees to protect and when to do it. Treatments are expensive, time consuming and add insecticides to the environment. This should only be done with forethought.

Currently, trees should be considered for treatment if the borer has been found in other trees within 10-15 miles. That is not the case as yet in Tulsa but likely will be in the future.

More information about the Emerald Ash Borer and preventative measures may be found on the website of The Emerald Ash Borer Information Network at emeraldashborer.info. Also look at the Oklahoma Forestry website for description of signs of the insect’s tree involvement.

Be aware that the OSU Extension Offices in Oklahoma will keep track of the spread of the beetle and publish information as to the locations.

Garden tips

§  Keep leaves off of newly seeded fescue to prevent damage to the sprouts. Also, the soil of newly seeded fescue should be kept moist until the sprouts are about 2 inches, then water less often and for longer times to encourage deep root growth of the seedlings.

§  Remove vegetable garden debris to prevent many garden pests and diseases from overwintering in these materials.

§  Plant cool-season cover crops like Austrian winter peas, wheat, clover and rye in otherwise fallow garden plots.

§  Cover water gardens with netting to keep out falling leaves.

Dividing Perennials in Fall

Perennials give clues when its time to divide, replant

Brian Jervis: Ask a Master Gardener

Saturday, October 22, 2016

Q: When should I divide my pampas grass? What about my iris? G.W., Tulsa

A: Pampas grass is a perennial, a class of plants in which the tops die back in winter but re-emerge from roots in spring. A general rule of thumb for dividing and replanting perennials is that it depends on the time of blooming. For those blooming in spring, fall division may be best, and for those blooming in summer and fall, divide in spring (or after fall blooming is completed).

There are many types of perennials, and not all fit into the above recommendations about when to divide. Some do best not divided at all, unless new plants are needed.

Perennials will often give you clues as to when they need dividing. With increase in density of the root system, the center of the root ball often dies so the plant may have little or no growth in its center. Also with crowding of the roots, the whole plant simply doesn’t perform as well, with substantially less growth and numbers of blooms. Another reason to divide is if the plant has simply outgrown its space.

As to when to divide Pampas grass, it seems to do best divided in the early spring after the dead foliage has been cut back to a height of 6 inches or so. Like many other perennials, the whole root ball can be dug up and cut into pieces or sections of the roots removed while the remainder stays in place. In any case, many of the grasses, and especially Pampas grass, have extremely tough root balls and an ax will usually be needed to divide.

Perennials like black-eyed Susans, purple coneflowers, monarda and yarrow can be divided in either spring or fall, while asters, blanket flower, bleeding hearts, cannas and chrysanthemums do best if divided only in spring. Iris do best if divided at least a month after they complete spring blooming.

Plants that often need no division, unless new plants are needed, are hostas and peonies. Peonies are a little difficult to divide and replant in the sense that they must be replanted at the proper depth and, in some cases, may take 1-3 years before beginning to bloom again. Peonies should be dug up and divided in September or October.

When dividing, plan ahead. Water the plant and dig its new hole, if moving it, beforehand. Adding organic compost to the native soil at replanting is beneficial in all types of soils. When transplanting, take care to not let roots dry out; a cloudy day is best.

A benefit of dividing plants, other than improving their health, is that you will end up with several new plants to share with friends and neighbors.

For more information as to the time to divide and how to do it, consider going to the Clemson University Extension website and search for “dividing perennials.”

Garden tips

• ·       Plant container-grown trees and shrubs this month. Fall is generally the best time to plant. At this time, the plants have no energy drain to produce leaves and can concentrate on growing a root system until the soil gets cool in winter. They are better prepared for spring growth if planted in the previous fall.
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• ·       Check and treat houseplants for insect pests before bringing inside. Look at the roots and repot those that are rootbound. Irrigate the soil thoroughly before bringing inside. Spray with horticultural soaps or oils if there is evidence of insects.
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• ·       There is still time to plant radishes and mustard in the fall garden.
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Planting Azaleas in the Fall

Azaleas can be planted in fall or spring

Bill Sevier: Ask a Master Gardener

Saturday, October 15, 2016

Q: What time of the year is it best to plant azaleas? How best to plant them? K.D., Tulsa

A: Ideally, azaleas should be planted either in early spring or in fall after it cools. Either time is acceptable.

When planting in fall, it is suggested that you delay mulching until after the first frost so the plants will be assured of developing dormancy for winter.

Azaleas have some cultural needs that are a bit different from many other shrubs, at all times of the year. The chief difference is that they need an acidic soil, with a preferred pH (measure of acidity) in the 4.5 to 5.5 range. Our native soils do not normally have this degree of acidity, so some adjustments are usually needed.

To determine soil acidity, along with information about the nutrients nitrogen, phosphorus and potassium, have a soil test performed before planting. Instructions on how to perform a soil test and also how to plant azaleas may be found on the Master Gardener website.

If more acidity is needed, there are two options. The best option is to mix peat moss 1:1 or 1:2 with native soil. Peat moss is acidic and will usually produce an adequate pH. Another way to add acidity is to use elemental sulfur (pure sulfur) and mix it into the soil. The amount of sulfur to add depends on the pH, but a safe amount to use would be 7 tablespoons for every 10 square feet of soil. Sulfur will not immediately lower pH; it takes a few months for this to occur.

Azaleas have fine, shallow net-like roots. To plant them, create a blunt cone of soil, spread the roots out over the cone like an umbrella and cover with several inches of soil.

In well-drained soils, plant azaleas at the same level as they grew at the nursery — never deeper. If your soil is heavy clay, as it often is, it is best to plant above ground in a large mound of prepared soil. Spread the roots out and plant them on top of the mound, with a few inches of soil for cover.

In both cases, they should receive generous amounts of loose mulch at the time of planting and yearly thereafter. There is no best mulch. Any mulch that is loose is useful. Contrary to popular belief, there is no mulch that will add acidity to the soil.

All the plants need generous irrigation during establishment and subsequently in all seasons.

A slow-release fertilizer, such as Osmocote, may be mixed with the soil at the time of planting and, if so, no further fertilizer will be needed the rest of the following growing season. Azaleas, in general, need less fertilizer than other shrubs and will suffer if excessively fertilized. If mulched yearly, adequate nutrients may be supplied by the decaying mulch.

Garden tips

• Peonies, daylilies and other spring-flowering perennials should be divided or planted now.

• Dig and store tender perennials like dahlias and caladiums in a cool, dry location. Cannas and elephant ears can also be dug, but most will survive the winter fine if mulched heavily and in a sheltered area.

• Plant fall mums and asters, and keep them watered during dry conditions. Don’t crowd because they take a couple of years to reach maturity.

• As leaves begin to drop, keep them off any newly seeded fescue lawns