Sunday, September 16, 2018 0 comments By: Jack Downer

Reseeding Fescue Lawns in Fall

Reseeding Tall Fescue in Fall
Brian Jervis: Ask a Master Gardener
Sunday, September 16, 2018
Q: It seems like my fescue thinned out this summer. How do I re-seed and when is the best time? DH
A: Fescue is a good choice for areas of your landscape that get some shade. It thrives in spring and winter but struggles with our Oklahoma summers. As a result, most of us need to re-seed our fescue each year to keep a thick, healthy turf.
Cool-season grasses, like fescue, germinate best when the soil temperature is in the 70-degree range. This happens in the spring and fall, but fall is the best time to re-seed as this gives your new fescue the fall, winter and spring to develop a healthy root system. The last half of September through the first half of October usually gives us the soil temperature we need.
Oklahoma is fortunate to have the Oklahoma Mesonet (, which provides us with a wealth of information, including the soil temperature for each county. At this writing, 2-inch soil temperature in Tulsa County is 72 degrees, so this is perfect.
For optimal results, we recommend purchasing seed with a blend of at least three different types of seed rather than a single cultivar. Doing so not only increases your likelihood of success, but also combining grasses tends to reduce the incidence of disease as each type tends to mask the weaknesses of the others.
It is also a good idea to prepare your soil rather than just sprinkle seed on the ground. The upper layer of soil tends to develop a crust so seeds dropped on this hard surface will either blow or wash away before having a chance to germinate. Breaking up the soil can be done with a rake or by perhaps renting a tiller or verticutter for difficult situations.
Seed should be sown evenly with either a rotary or drop spreader and applied at a rate of 3 to 6 pounds per 1,000 square feet when reseeding.
Seeds must have water to germinate, which typically means watering twice a day for a few minutes during the first two to three weeks. The key is to keep the seeds moist. Once the seedlings are 1 to 2 inches tall, you can begin watering less frequently and for longer periods.
Fertilization will also be necessary, and we recommend getting a soil test from the OSU Extension so that you will know exactly which nutrients your soil requires for best results.
One word of caution: If you plan to re-seed this fall, do not use a weed pre-emergent as this will not only work to prevent weeds from growing but will also prevent your new fescue from growing.
We have quite a bit of information at our Diagnostic Center and on our website to help you maintain your new and existing turf: click “Lawn & Garden Help” and then select “Turfgrass” for fact sheets and videos (
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 1 pound of actual nitrogen fertilizer per 1,000 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.
  • 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, which do well in our area.

Sunday, September 2, 2018 0 comments By: Jack Downer

Control of Bagworms on Trees and Shrubs

Control of Bagworms on Trees and Shrubs
Allen Robinson: Ask a Master Gardener
Sunday, September 2, 2018
Q: I am seeing lots of bagworms on my cedar trees and other trees right now. What can I do to get rid of them? Charlotte S., Tulsa
A: Bagworms are common pests on eastern red cedar, other junipers, arbor vitae and sometimes on bald cypress, elms, pines, willows, maples and others. They are unique in that once they form their protective bag later in the summer, insecticides are not helpful. Treatment should begin soon after the eggs hatch in late spring.
The cycle of worm production begins in the spring when eggs that have overwintered in bags hatch. Newly hatched larvae develop small, upright bags while feeding on the plant. Initially, the bags are less than ¼ inch but, when mature, they can reach up to 2 inches in length. Once mature, the larvae close off the bag and fix it to the tree. In mid-summer, the males emerge from bags, fly around and mate with females who never leave the bags. The females lay eggs in the bag and then die. The cycle begins anew in the following spring.
For smaller trees with small infestations, the easiest treatment is to simply pull the bags off and destroy them. This can be done at any time of the year. Be sure to burn them or place them in a well-sealed bag to destroy the bags and their viable eggs. Trees that have heavy infestations yearly should be treated with an insecticide because large numbers can completely defoliate and kill smaller trees.
Insecticide treatment must be done soon after the larvae hatch in late May or early June. No treatment is considered effective once the bag is closed. Be patient as most insecticides will require repeat applications every seven to 10 days for two to three treatments because not all eggs hatch at the same time or there may be migration (wind dispersal of small larvae during June) from other host trees.
There are two relatively safe organic insecticides. The safest is Bacillus thuringiensis kurstaki, or “Bt,” sold as Thuricide and other brands. The good news about this herbicide is that it is not harmful to people, pets or fish. It is a bacterium that infects the bagworm and causes it to starve. It must be sprayed directly on young larvae.
Another biological insecticide derived from a bacterium is Spinosad, a microbial agent that is sold in several brands including Fertilome Borer, Bagworm, Tent Caterpillar and Leaf Miner Spray. Spinosad has contact and systemic activity on target insects. It, too, has low toxicity and a good environmental profile. Be sure to always read all label directions.
Other nonorganic manufactured insecticides are labeled for bagworms and are effective in controlling young worms. However, these insecticides also kill the parasites and predators that normally keep bagworms under control.
So, while the most viable way to rid your trees of bagworms at this time of year is to pick them by hand and destroy them, consider keeping this information handy so that next year the problem can be dealt with in late spring.
Garden tips
  • If your tomatoes are too tall and gangly, now is a good time to prune the top of the plants by as much as ⅓ to ½, depending on the plant. This will stimulate new limb growth and new fruit production after it cools.
  • Reseeding fescue is best done from mid-September through mid-October. If you plan on reseeding, begin scouting for good seed now. Purchase a fescue blend of three or more varieties, with or without Kentucky bluegrass. Read the label on the seed bag. A good blend will have 0.01 percent or less of undesirable “other” crop seeds.
  • In the 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 1½ 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.
  • The last nitrogen fertilizer application of the year on warm-season grasses should be applied no later than Sept. 15.

Sunday, August 19, 2018 0 comments By: Jack Downer

Don't Miss Out on Fall Vegetable Gardening

Fall Vegetable Gardening is Not to Be Missed
Tom Ingram: Ask a Master Gardener
Sunday, August 19, 2018
Q: I plant a vegetable garden every year in the spring, but I have never tried a fall vegetable garden. What can I plant in a fall garden and when do I plant? SM
A: Oftentimes, fall vegetable gardens get overlooked because we don’t know what to plant, or maybe we are just tired from our spring and summer gardens and ready to call it quits. Either way, growing fresh vegetables can be a year-round activity. And what you may not realize is that some of the best and tastiest vegetables are grown in the fall when warm sunny days and cool humid nights create wonderful growing conditions.
You can divide fall crops into two groups: “tender” and “semi-hardy.” “Tender” means these vegetables will need to reach full maturity and production before the first frost brings their season to an end. “Semi-hardy” means they may continue to grow and be harvested after several frosts. In northeast Oklahoma, Nov. 15 is our average first freeze date. So, unless something unusual happens (in Oklahoma?), you can have fresh vegetables straight from the vine until November and then refrigerate the rest for continued enjoyment.
With the cooler weather we are having (watch it change since I wrote that), now is the perfect time to plant a variety of tender and semi-hardy crops. Tender varieties you could plant now would include bush beans, lima beans, cucumber and squash. Semi-hardy crops would include cabbage and cauliflower (transplants), collards, potatoes (seed potatoes), kale, kohlrabi, lettuce (a little late, but I did anyway), parsnips, radishes, swiss chard and turnips.
Starting in September, you can plant garlic and onions, which are great crops to start in the fall as they grow all winter. If you do this, in late spring next year, you can harvest fresh garlic and onions to last you the entire year (if you grew enough).
Mulch should be an important part of your garden strategy any time of year as mulch helps retain moisture, as well as reduces weeding. In addition, mulch controls soil temperature swings during the day, which helps keep those tender roots happy.
Oftentimes, people contact us wanting to know what type of fertilizer would be best for their situation and how much they should use. There is really no good way to answer this question without testing your soil.
Getting a soil test is not hard. All you need to do is get 15-20 samples of soil from your garden and put them in a bucket. Be sure to dig down about 6 inches with your trowel for these samples. Remove any nonsoil debris and mix up the soil. Then, bring about a sandwich bag’s worth to the extension office. We’ll send it off to Oklahoma State University, and within about 2 weeks, you will know the basic nutrient content of your soil and how to best amend it for optimal results. The test will cost you $10, but in my view, it is likely the best $10 you will ever spend. Happy gardening!
Garden tips
  • Discontinue deadheading roses by mid-August to help initiate winter hardiness.
  • Irrigated warm-season lawns, such as Bermuda and zoysia, can be fertilized once again; apply 1-pound Nitrogen per 1,000 square feet this month. Do not fertilize these grasses after the end of August. Do not fertilize tall fescue lawns in summer; fertilize in late September after it cools and again in November.
  • This time of the year is generally not the best time to prune, but if you have damage to trees and shrubs due to storms, prune out the damage now.

Sunday, August 5, 2018 0 comments By: Jack Downer

What is a Master Gardener and How do I Become One?

Becoming a Master Gardener
Tom Ingram: Ask a Master Gardener
Sunday, August 05, 2018
Q: At the beginning of each of the classes we teach in elementary schools throughout Tulsa County, we typically ask the students a question: Who knows what a Master Gardener is?
A: We get all kinds of answers (as you might imagine) — “someone who is good at gardening” (we hope), “someone who likes insects” (most of the time) and “someone who likes plants” (always yes.)
Truth is, the question does not come with a simple answer because Master Gardeners do so many different things.
By definition, Master Gardeners are volunteer educators for the Oklahoma State University Extension service on a mission to provide research-based horticultural information to local home gardeners and the community. But, that mission can take many forms.
One of the ways we fulfill that mission is by staffing a horticultural Diagnostic Center at the OSU Extension office Monday through Friday. Between the hours of 9 a.m. and 4 p.m., you can find Master Gardeners on hand to answer your questions via phone, email or in person. Outside our Diagnostic Center, you will find our beautiful Master Gardener-maintained demonstration garden containing more than 200 annuals, perennials, shrubs and trees.
We also teach a variety of classes, such as our spring and fall Lunch and Learn series at the Tulsa Central Library, or our yearly Urban Gardener classes. Topics include plant biology, soil chemistry, growing fruits and vegetables, lawn care, tress and shrubs, flowers, container gardening, etc.
We mentioned the public schools. Master Gardeners teach a variety of science-based classes to elementary school students throughout Tulsa County. Last year, we taught these classes to approximately 16,500 students.
In addition, each year we also host an Insect Adventure for more than 1,000 third-graders, which helps these students gain a respect for the wonderful variety of insects we share this planet with and the many benefits they provide.
You may also have seen Master Gardeners at an Herb Festival or perhaps at our beautiful exhibit at the Home & Garden Show. Or, you may have visited one of our homes in the Master Gardener Garden Tour we host each spring.
Some Master Gardeners visit nursing homes to spend time with seniors while engaging in a little horticultural therapy to brighten their day. Others landscape yards for Habitat for Humanity homes so these new homeowners don’t just get a house but a beautifully landscaped home. And other Master Gardeners spend hours planting and maintaining beautiful flowers in planters in the Brookside and Blue Dome districts to help keep Tulsa beautiful.
So, now that you know what a Master Gardener does, do you want to come join us? At 10 a.m. Aug. 8 and 1 p.m. Aug. 15, you can attend a presentation at the OSU Extension (4116 E. 15th St.), where you can find out the requirements to become a Master Gardener and fill out an application. This enrollment only happens once a year, so if you have an interest, be sure to attend one of these presentations.
Garden tips
  • Fertilization of warm-season grasses can continue if water is present for growth. Do not fertilize Bermuda or zoysia lawns after the end of August. Do not fertilize fescue lawns until it cools off in September.
  • Mowing heights for cool-season turf grasses should be at 3 inches during hot, dry summer months. Gradually raise mowing height of Bermuda lawns from 1½ to 2 inches.
  • Cucumbers may be bitter this time of year and vines quit producing. This is due to the heat. If you are able to get the vines through the summer, after it cools, they will be fertile again and the taste of the cucumbers will improve.

Sunday, July 22, 2018 0 comments By: Jack Downer

Azalea Problems and Proper Care

Azalea Care

Brian Jervis: Ask a Master Gardener
Sunday, July 22, 2018
Q: I have azalea bushes that are so beautiful in the spring but then develop problems over the summer. Should I just live with these issues or is there something I can do to help make them look better through the summer? Michelle T., Broken Arrow
A: Landscapes bursting with healthy plants give us splashes of color that change with the seasons, and azaleas are ideal centerpieces for flowering shrub beds, containers and even hedges.
However, the dream of such garden beauty sometimes comes into question when spots and holes appear in leaves, the foliage turns yellow or flower buds remain closed. While azaleas can withstand many of the insect and disease problems that plague other plants, there are still a few problems that can occur.
First of all, plant in the right location (east facing with good morning sun is the best), with good drainage and air circulation between plants to help prevent problems. However, when that is not sufficient, here are a few of the most common offenders:
Aphids: These may appear on the stems of any plant when the weather is humid and plants are too close together without enough air circulation. Treat aphids with a hard spray of water from the hose.
Lace bugs/spider mites: Azalea lace bugs make up about 90 percent of all azalea pest problems. They feed on leaves, creating speckled areas on the leaf surface. Spider mites cause white stippling on leaves first, but then the area turns a rust or gray color. Both can be treated with insecticidal soap, horticultural oils or a systemic insecticide that includes the ingredient imidacloprid. Use it as a soil drench once yearly after blooming to avoid harming bees.
Fungus-related issues: Leaf galls, rust, petal blight and leaf spot are caused by fungus. Petal blight appears as tiny white spots on flowers. Leaf spot manifests as brown blotches that grow in size. Treat with a fungicide.
Root rot/water mold: Azaleas may also be impacted by another fungus that causes root rot, sometimes called water mold. Azaleas that stand in water during warm weather are particularly susceptible. This occurs mostly when azaleas are planted as a foundation plant near a down spout. This fungus spreads fast, so watch for yellowing leaves and wilting plants.
Iron Chlorosis: Azaleas prefer acidic soils. If not planted in such, leaves will turn yellow. With this condition, a soil test is always in order, which can confirm the actual soil pH.
To assist in preventing these issues, azaleas should be mulched with several inches of pine bark, and some of the bark should be incorporated directly into the planting soil to help add oxygen and ensure thorough drainage.
Protect your valuable and beloved plants with regular attention, looking carefully for potential problems along stems and branches, as well as under leaves. And, when it comes to chemicals, more is never better. Small infections and infestations may go unnoticed, only to grow into larger issues later. Therefore, it is best to examine your azaleas every time you water.
For more information and assistance with azaleas, drop by the Tulsa County Extension Office or call the Master Gardener hotline at 918-746-3701 to speak with a Tulsa Master Gardener.
Garden tips
·        When watering your lawn, ornamentals or vegetables, always do so in the morning, if possible. If watered in the evening, plants will go into the night still moist. Most disease-causing organisms need moisture and, because they grow best at night, leaving leaves wet in the evening will promote many plant diseases.
·        Bulb onions are ready to harvest when the tops fall over. They should be removed and allowed to dry in a well-ventilated, shaded area. After the tops are completely dry, they may be stored in a cool, dry area.
·        Tomato production stops in the heat of the summer. Most tomato pollen becomes infertile and blossoms drop off when the night temperatures are above 70 degrees and daytime temperatures are above 92 degrees for a few days. Tall, spindly tomato plants with scarce fruit are usually due to either too much nitrogen fertilizer or too much shade. If this occurs, cut them back by ⅓. New growth and fertile blossoms will develop when it cools in the fall.

Sunday, July 8, 2018 0 comments By: Jack Downer

Squirrels and Other Pests in the Vegetable Garden

Squirrels and Other Pests in the Vegetable Garden
Allen Robinson: Ask a Master Gardener
Sunday, July 08, 2018
Q: Squirrels and other animals are eating my tomato plants. Help! What can I do? — Melissa R., Tulsa
A: Keeping animals out of tomato plants can be difficult and methods vary depending on the animal. For example, keeping deer out with a fence can be tricky because they can jump a fence shorter than about 9 feet. A barking dog is often the best deterrent for deer, and cats can be effective protectors against squirrels and other small animals. For some burrowing animals, a fence must be buried several feet deep to keep them from digging under it. And, for highly intelligent and adaptable raccoons, only a full cage may keep them out of tomato plants. Fake owls or snakes can help keep rabbits at bay.
With their acrobatic maneuvers and feisty chattering, squirrels often inspire smiles and laughter. But for gardeners who find beds dug up and tomatoes chewed, these bushy-tailed critters aren’t a source of anything except frustration and a fervent desire to figure out ways of keeping them out of the garden. They sometimes eat part of a tomato and leave the rest behind. Other times, they eat the entire fruit. Other favorite meals of squirrels include beans, squash, cucumbers and eggplants. And, occasionally, squirrels will unearth young potted plants in their quest to bury nuts.
Like other rodents, squirrels have long incisor teeth that never stop growing, so they tend to gnaw on all sorts of materials to keep those teeth on the short side. Various anti-squirrel techniques are recommended, depending on your preferred plan of action.
Here’s a listing, from harmless to harmful:
Clean up: The sight and smell of fallen fruit, nuts and seeds can lure squirrels to your yard for feeding. Clean up these items beneath trees and bird feeders. Make sure trash can lids fit securely to keep squirrels from discovering treats in the garbage.
Structure: Erect a fence. Wire fencing, such as hardware cloth, plastic bird netting or chicken wire, can keep squirrels out. Be sure to bury the wire deep so they can’t dig under it; keep the wires close together so they can’t squeeze through it.
Annoy them: Bother the squirrels by using motion lights or commercial devices that make high-frequency sounds. Surround the garden with unpleasant repellents, such as garlic, ground hot peppers or urine from predators such as wolves. Search online for products that contain capsaicin, the ingredient that gives hot peppers their heat.
Scare tactics: Having an outdoor dog or cat will drive squirrels away. Barn owl houses also scare squirrels away because owls are known to eat squirrels. Many have success simply with fake snakes.
Permanent solutions: If all else fails, consider commercial traps or poison. Place bait, such as peanut butter or sunflower seeds, in a live trap. When a squirrel is captured, release it far away from the garden. If you are not opposed to killing squirrels, you can also use poison bait traps, but be sure to follow the manufacturer’s instructions.
Garden tips

  • For all your plants, ornamental or vegetable, mulching and correct watering are keys to surviving the heat of the summer. Mulch conserves water and reduces ground temperature.
  • Fescue lawns need 2 inches of water per week to survive summer; Bermuda grass needs about half that amount. Watering less frequently and more deeply is much better than daily shallow watering.
  • Brown patch disease of fescue lawns is appearing now, related to excessive rains, high heat and high humidity. Wet grass leaves promote the disease. Therefore, if you water in the mornings, allowing the leaves to dry during the day, there will be less likelihood of infections. Fungicides are available, but OSU feels the fungicides available to homeowners are not nearly as effective as those available to professional licensed applicators. None of these chemicals will cure existing infections; they only prevent new disease at best.

Sunday, June 24, 2018 1 comments By: Jack Downer

Tomato Growing Challenges in Oklahoma

Tomato Growing Challenges
Brian Jervis: Ask a Master Gardener

Sunday, June 24, 2018

This time of year, we get a lot of questions about one of our favorite garden crops: tomatoes. We love our tomatoes, but there are a variety of challenges associated with growing them.
One of those challenges is Septoria leaf spot. Septoria leaf spot is a common fungal disease in Oklahoma. Starting at the bottom of your plant, you will notice leaves with yellow areas that become circular with grayish centers and dark borders. The spores from septoria can be quite aggressive, spreading upward throughout the plant.
When you see this, it’s time to begin a fungicidal spray program of copper fungicide on a 7- to 14-day schedule. This will not cure the infected leaves but will diminish its ability to spread. Infected leaves should be removed.
Also, to minimize exposure and spreading of fungal diseases, tomatoes should not be watered via an overhead sprinkler system, as the splashing water tends to provide a means through which the disease can migrate. Drip irrigation is preferable in most instances.
If you are having problems with fungal diseases, be sure you are rotating your crops. Planting the same crop in the same spot year after year tends to encourage these fungal diseases to develop. However, when rotating crops with tomatoes, do not put peppers, eggplants or potatoes in the same rotation as they all tend to be susceptible to many of the same diseases.
Another common challenge to growing tomatoes successfully is blossom-end rot. Symptoms manifest in an expanding, tan, water-soaked area of the blossom end of the fruit. Blossom-end rot is a complex disorder, which is thought to be caused by a calcium deficiency. However, the solution is not often as simple as adding calcium to the soil.
High temperatures and wind, fluctuating water availability and a little drought stress thrown in (sounds like Oklahoma) create an environment in which you may see blossom-end rot. Somewhat ironically, excessive soil moisture for a long period of time can also contribute to this problem, as it tends to damage the root system and diminish the plant’s ability to uptake calcium. Excessive fertilization with nitrogen can also be a contributing factor.
Just remember, calcium deficiency is rarely a direct cause of blossom-end rot. It is similar to how a fever is an indicator of a problem and not the actual problem. Adding calcium can be of little value if the blossom-end rot is the result of environmental conditions mentioned above.
These are only two of the many challenges we face growing tomatoes. You can find several relevant fact sheets on the topic by visiting the Lawn & Garden page of our website,, and then clicking on “vegetables.”
Garden tips
  • Vigorous, unwanted limbs should be removed or shortened on new trees. Watch for forks in the main trunk, and remove the least desirable trunk as soon as it is noticed.
  • Most varieties of mums are more productive if “pinched back” now. Either pinch off with fingers or cut to remove an inch or so of limb tips above a leaf. This results in the growth of new limbs and a fuller plant. Do not pinch after mid-July or it will interfere with fall blooming.
  • Watch for tiny, sap-sucking insects called aphids on roses, perennial flowers, shrubs and vegetables (especially tomatoes). They produce a sticky substance called “honeydew." Many can be dislodged with a hard spray from your garden hose or two applications of insecticidal soap will usually greatly reduce any aphid damage to your plants.
  • Crapemyrtles are one of the few shrubs that should be planted in the middle of summer. Growth of new roots of these plants occurs best with summer soil temperatures.