Wednesday, August 30, 2017 0 comments By: Ask A Master Gardener

Fairy Rings are Varieties of Common Mushrooms

Fairy Ring Type of Mushrooms
Brian Jervis: Ask A Master Gardener
Tuesday, August 19, 2017
Q: There are mushrooms all over my yard and that of my neighbor’s. Are they harmful? What should I do about them? Tom B., Jenks
A: The summer of 2017 has been a bit abnormal. We have had few century-degree days and much more rain than usual. While the rain is truly beneficial to our flower beds, gardens and lawns, it can cause other undesirable issues, such as mushrooms and fairy rings.
Mushrooms are actually part of a fungus that grows underground, well hidden from sight. Your yard is naturally full of fungi (plural for fungus) and spores, some harmless and some problematic. Fungi are interesting as they are one of the few things in our yard that do not get their nutrients from photosynthesis. Fungi receive nutrients by either decomposing or consuming organic matter.
Another phenomenon of mushrooms is commonly known as a fairy ring. These rings are also known as fairy circle, elf circle, elf ring or pixie ring and are produced by many varieties of underground fungi. Fairy rings are simply an organized pattern of fungi, typically circular in nature. They typically expand from a central point into an arc or circle and are particularly noticeable when they grow in our lawns.
The ring’s appearance is variable and may occur in all types of turf grass. They may appear as green rings, brown rings or simply a ring of mushrooms. The rings range from a few inches to many feet across and may persist for years.
The fungus that causes these rings feeds on organic matter in the soil. As it feeds, it frees up the nutrient nitrogen in the organics, accounting for the dark green rings. Typically, most lawn fungi and their mushrooms don’t actually harm the health of a lawn. However, in some cases, the older fungal mass may be dense enough to prevent water penetration and actually starve the grass from nutrients, thus producing a ring of dehydrated dead grass.
Mushrooms, toadstools or puffballs may appear overnight, especially after a rain. They are the fleshly, spore-bearing fruiting bodies of the underground fungi. To be on the safe side, all of these mushrooms and puffballs should be considered poisonous and should be removed as soon as possible.
Management is not easy. Once the disease appears, it is difficult to eliminate. There is no natural control. Most people opt for greening the lawn with recommended amounts of nitrogen fertilizer, which effectively masks/hides the ring but does not eliminate it. Other measures you can take: remove mushrooms by regular mowing or raking; water deeply to minimize the loss of grass due to the fungal dehydration; remove excess thatch and aerate compacted soils; encourage beneficial soil microbes by top dressing with a humus builder, such as well-aged manure or finished compost. However, if grass is lost, reseeding or re-sodding may be needed.
There are fungicides labeled for fairy ring control, but most are not effective and usually require a certified professional for application. Your mantra should be to fertilize, water, aerate and mow. Unfortunately, the only option for complete elimination of the fungus is to remove and replace the soil and grass.
Garden tips
·        Always follow directions on the labels of synthetic and natural pesticide products. Labels will always list where the product may be used and which pest it is certified to cover. If you spray pesticides, do it early in the morning or late in the evening after bees have returned to their colony.
·        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, there is no “best” variety. 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.

Collecting Rainwater

Collecting Rainwater is Easy and Inexpensive
Tom Ingram: Ask A Master Gardener

Tuesday, August 22, 2017

Q: I hate to waste all this rain we’ve been having; should I consider building some type of rainwater harvesting system for my garden? B.C.
A: Rainwater harvesting is the process of capturing, channeling and storing rainwater for later use. Methods of harvesting rain date back more than 4,000 years in areas such as Rome, the Middle East, and China. Today, rainwater harvesting systems can be implemented at home with a little bit of planning and effort.
For homeowners, rain barrels are a simple and relatively inexpensive solution for residential water conservation. This is especially the case since the average residential roof will produce a large amount of runoff with little rainfall.
Harvesting systems can be as simple as a barrel under a gutter with a spigot at the bottom, or they can be an elaborate series of barrels for much larger holding capacities. The limiting factor in most systems is the space available and aesthetics.
One factor to consider in your rainwater harvesting system is the weight of the water. With water weighing 8.34 pounds per gallon, a 50-gallon plastic barrel can weigh more than 400 pounds. Since rain barrels should be elevated to allow gravity to help with water distribution, you should always place your rain barrel on a sturdy and solid platform.
Your system will also need a method to divert water after your collection system is full. Diverters are available that return overflow water to your gutter or perhaps you could use a hose to direct the overflow water away from the house. Filter screens should also be used to prevent mosquitoes from breeding in your rainwater collection system.
Because dust and bird droppings can accumulate on the roof between rainstorms, the first rooftop runoff often contains higher concentrations of these contaminants. To counter this, some rainwater collection systems include what is called a “first flush diverter.” This can be thought of as a kind of pre-harvest collection reservoir to help keep these contaminants from getting into your water.
To prevent algae growth, above-ground collection systems should be opaque, heavily tinted and have sun barriers. Painting your rain barrel is a good way to express your creativity and help your rain harvesting system become a beautiful addition to your garden rather than an awkward accessory.
We have fact sheets on how to design a rainwater harvesting system online and at our Diagnostic/Help Center, or you can visit the Oklahoma Gardening YouTube page and search for “rain barrel,” where you will find two instructional videos on how to make your own water harvesting system.
Garden tips
·        August is a good month to start your fall vegetable garden. Bush beans, cucumbers and summer squash can be replanted for another crop. Beets, broccoli, carrots, potatoes, lettuce and other cool-season crops can also be planted at this time.
·        Discontinue dead-heading 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.

Tuesday, August 15, 2017 0 comments By: Ask A Master Gardener

Armyworms in Turfgrass

Lawn Armyworm Diagnosis and Control

Allan Robinson: Ask a Master Gardener
Tuesday, August 15, 2017
Q: Something is eating my grass, and my neighbor says he thinks these are armyworms. How do I tell if they are armyworms and what should I do? A.M., Tulsa
A: Armyworms are not actually worms. They are the larvae, or caterpillar, of a moth, and they love to eat grassy plants. They prefer grain crops (peanuts, cotton, soybean, wheat), but they can spill over into nearby lawns and move from lawn to lawn from there. Large numbers can consume all above-ground plant parts, and they are capable of killing or severely retarding the growth of grasses. The overall numbers are more pronounced in dry years.
Fall armyworms don’t necessarily wait until the fall to do their damage. Larvae are present by late July, so they are here now. They produce several generations per summer, but the September generation is the one that damages lawns.
Caterpillars or mature larvae are green, brown or almost black and about 1½ to 2 inches long, with black and reddish brown stripes on each side of the body and four small, black spots on the dorsal side of each abdominal segment, with a marked pale, inverted “Y” on the front of the black head capsule.
If you find a patch of lawn suddenly wilting, move the grass aside and look at the soil. If you see several beige-gray caterpillars eating the grass at the soil-line, you probably have armyworms. But, to effectively search for them, mix one tablespoon of liquid dish washing soap to a gallon of water and pour it onto a square-foot area of grass. This should bring worms to the surface within a few minutes, and you can see them by separating the blades of grass. You should do this on two or more areas of the lawn and compare results.
If you find two to three worms per area, you should treat the lawn
Garden tips
  • It is not advisable to use post-emergent broadleaf weed killer during the peak heat of summer. Wait a bit. Weeds will start to grow when it cools.
  • The birds need a handy source of water, as well as food. Put out a big saucer of water and watch them not only drink but also take baths to cool off and remove parasites. Another saucer of water filled with stones and sand will be a watering hole for butterflies and other beneficial insects.
  • If you are seeing scattered tips of limbs on trees turning brown with some falling to the ground appearing to be broken off, this is likely cicada damage. The adults dig into the bark of a stem about 6 inches from the tip and lay eggs. The limb tip usually dies and may fall to the ground. It commonly involves oaks, but other trees can be affected as well. The amount of damage is nominal and will be of little consequence.

Tuesday, August 8, 2017 0 comments By: Ask A Master Gardener

Cicadas--Loud but Harmless to Plants

Cicadas--Loud but Harmless

Brian Jervis: Ask a Master Gardener

Tuesday, August 8, 2017
Q: It seems like there are so many cicadas this year. Are they going to hurt my plants in any way? GM

A: We have been getting calls in our diagnostic center from people trying to identify these beetle-like insect shells they are finding in their yards and wanting to know what that loud sound is coming from their trees. The shells and the sound are from cicadas, and if you aren’t from Oklahoma, the sheer volume a tree full of cicadas are capable of generating can be unnerving. But for locals, it reminds us summer is here.
There are several types of cicadas. The species we are most familiar with is called the Dog-Day Cicada. These cicadas typically have a life cycle of between 2 and 5 years. The sound you hear coming from the trees is actually the male cicada singing to attract females. The males produce this sound by rapidly beating their wings against their abdomen. On each side of the abdomen, there is a specialized organ called tympana, which increases the sound of this beating considerably. These mating calls have been recorded as loud as 108 decibels, which is about the same sound level as an automobile horn from about 3 feet away.
Once the male’s singing has attracted a willing partner, the female cicada lays her eggs into twigs and small branches using a somewhat saw-like egg-laying structure called an ovipositor. Six to seven weeks later, the small nymphs hatch, drop to the ground and burrow into the soil, sometimes several feet deep, where they live out the majority of their lives growing through several growth stages called instars.
When they are ready, the fully developed cicada nymphs burrow out of the ground at night, leaving an exit hole about the size of a nickel. Once out, they climb up onto a tree, fence or low plant where the adult cicada emerges from its final nymph stage, leaving behind that light brown shell or exoskeleton with which we are familiar. These adults can live 5 to 6 weeks during which the process of finding a mate begins again.
Oklahoma is home to at least 12 species of cicadas, one of which is a periodical cicada whose life cycle is an impressive 17 years, the longest life cycle of any known insect. Most periodical cicadas in Oklahoma belong to what biologists call brood IV and were active in 1947, 1964, 1981, 1998, 2015 and will be back in 2032.
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.
·        Establishment of warm-season grasses, such as Bermuda and zoysia, by sodding or sprigging should be completed by the end of July to ensure the least risk of winterkill.
·        Mowing heights for cool-season turf grasses should be at 3 inches during hot, dry summer months. Gradually raise mowing height of Bermuda grass 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.

Tuesday, August 1, 2017 0 comments By: Ask A Master Gardener

Crapemyrtle Bark Scale

Crapemyrtle Bark Scale

Allen Robinson: Ask a Master Gardener
Tuesday, August 1, 2017
Q: I have white spots that turn to a blackish mold on my crape myrtles. What is it and how do I get rid of it? Tricia, Tulsa.
A: We addressed this issue in this column last year, but some of the recommendations made by OSU regarding control have changed. The current recommendations come from Dr. Eric Rebek, state extension specialist for horticultural insects.
It is an insect pest that is called crape myrtle bark scale. This insect is relatively new to our area but has become fairly prevalent. It came to the U.S. from Asia and first appeared in north-central Texas in 2004. It has subsequently spread northward into the Tulsa area from nursery stock and other sources of imported crape myrtles. This is the reason one should always inspect nursery crape myrtles for scale insect before purchase.
Like other scales, the life cycle begins with either the female scale or eggs overwintering on the crape myrtle under loose bark. When the eggs hatch, small mobile “crawlers” are produced, which migrate on the plant and may be spread to other crape myrtles by wind or birds. There may be two to three generations produced per year depending on temperatures.
Once the female is fully developed, she mates and attaches to the stems and trunks of the crape myrtle, 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 crape myrtle. The mold is unsightly and creates a reduction in aesthetic quality, but it is not significant in terms of the plant’s health.
Garden tips

·        Divide and replant crowded hybrid iris (bearded iris) after flowering until August. When planting, take care not to plant the rhizomes too deeply. Cover them with an inch of soil or less. Do not mulch iris
·        Water all plants deeply and early in the morning. Most plants need approximately 1 to 2 inches of water per week. Rather than watering daily, water less often and more deeply.

·        Some trees such as sycamores and river birches lose large numbers of leaves in the heat of summer. Trees do this to reduce water loss from their leaves. It is a coping action by the tree; it is not dying.