Gardening This Weekend: May 14, 2020

A gardener’s life moves in 10-degree increments. It was 20’s and 30’s back in the winter. Then we had delightful 60’s and 70’s for a while. Folks in South and Southwest Texas have been hearing 90’s in their forecasts for some time already, and the rest of us are becoming familiar with that number as well. Here are the tasks of the second half of May, focusing especially on what you should do this weekend, weather permitting.

Hot-weather annuals. Caladiums can finally be planted (soils are warm enough). Coleus, begonias, angelonias, fanflowers, pentas, lantanas, purple fountaingrass, ‘Cora’ periwinkles (because of their resistance to disease), alternantheras, ornametal sweet potatoes – the list goes on and on. Shop at a really good independent retail garden center.
Perennials for summer color. Nurseries have excellent selections, but buy soon. They probably will not restock as summer approaches.
Lawns. You are coming into the best two weeks of the entire year to plant sod, seed or plugs. Go for it!

Continued Below

Last call to reshape your spring-flowering shrubs and vines. Do so lightly, however, because they’ve already produced a lot of new growth. Try to avoid unnatural square or round shapes.
Pinch growing tips out of fall asters, Mexican bush sage, mums, copper plants, coleus and other plants that tend to grow tall and lanky if you do not.
Prune to remove spent rose blooms as they drop their petals. If you are in the DFW area, give your rose plants a close check for rose rosette virus and remove the plants immediately and entirely if you see it. Visual inspections are adequate. See examples on my website.
Foliage of fall-flowering bulbs such as oxblood lilies, spider lilies and others has turned brown by now. It can be trimmed away to tidy the garden.

Apply high-nitrogen or all-nitrogen plant food to trees, shrubs, vines, groundcovers, annuals, perennials and turf. Yep! The same fertilizer will probably suffice with all of the plants that you’re growing. The Texas A&M Soil Testing Lab has been preaching that gospel for many years. Most of our soils have excessive amounts of phosphorus already.
Patio pots and hanging baskets with water-soluble, high-nitrogen fertilizer every week or two. Supplement it with a long-lasting, timed-release product.
Use iron/sulfur soil acidifier product to correct iron deficiency. (Yellowed leaves with dark green veins, most prominent on newest growth first.)

Dead St. Augustine should be replaced with plugs planted into the bare areas. (That presumes it’s in full or nearly full sun and did not thin and die due to insufficient sunlight.) Take all root rot (TARR) has been common and severe in much of Texas this spring. The fungicide Azoxystrobin (Scotts Disease-EX) is now the recommended treatment. TARR will be less of an issue as it turns warmer and drier.
Blossom-end rot is already showing on tomatoes. The ends of the fruit farthest from the stems are becoming sunken and turning dried and brown. This is almost always due to irregular and insufficient water. In very sandy soils it’s also possible that a shortage of calcium can add to the problem.
Chiggers are likely in bermuda that has not been mowed recently, also in weeds in fields, roadsides and even parks. Apply DEET repellent to your legs and feet, also to the outsides of your socks and shoes. They are microscopic, but their itch is as big as Texas.
Same DEET repellent is the best way to deter mosquitoes. Yes, there are other ways of keeping them from biting you, but they’re not as dependable. They are already quite a problem across much of the state.
Bagworms got an early start on junipers, arborvitae and other cone-bearing plants. Control them with Bacillus thuringiensis (“Bt”) or most other general-purpose insecticides. Left unchecked for 2-3 weeks they can kill a mature evergreen.
Oak leaf blister continues to cause problems with live oaks and other oak species. Leaves look like waffles and are falling to the ground. This fungus causes no long-term damage and cannot be controlled once it appears on the mature leaves.

Posted by Neil Sperry
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