Gardening This Weekend: August 24, 2023
Here are your assignments for this last weekend of August. See how many apply to your landscape and garden.
• Nursery stock can be planted now, but water it deeply every two days with a garden hose. Sprinklers will not do an adequate job of soaking to the bottoms of their root balls.
• You still have time for fall color plantings of marigolds, zinnias, celosia, copper plants, wax begonias, purple fountaingrass and pentas if you get your plants set out right away. Look for vigorous plants just coming into bloom whenever possible.
• Wildflower seeds for spring blooms. You would hope to catch early fall rains in the next few weeks to get them off to a good start. Buy scarified bluebonnet seeds (treated with acid to soften the seed coats) for most reliable germination. Do not plant where you have turfgrass growing, and do not plant where you will be using pre-emergent weedkiller granules.
• Finish planting broccoli, cabbage, cauliflower, Brussels sprouts, kale from transplants as soon as possible. Leafy and root vegetable crops can be planted all across Texas now.
• Remove all rose bushes identified as having rose rosette virus. Characteristic symptoms: clubby, malformed growth. Buds that don’t open properly. Ultra-strong “bull” canes. Unusually thorny stems. Somewhat gradual to rapid decline of vigor of plants. Click to see photos and information on RRV on my website. Infected plants must be destroyed immediately.
• Spent flower stalks and browned foliage from perennials. Do not trim off any green leaves (iris, for example).
• Erratic shoots from spring-flowering shrubs, but avoid formal shearing.
• Flowerbeds and fall vegetable plantings with high-nitrogen plant foods to keep crops growing, producing vigorously.
• Apply all-nitrogen fertilizer to lawngrasses, landscape shrubs and groundcovers, flowers and vegetables. Look for a quality type with 30 to 40 percent of its nitrogen in slow-release form. Water deeply after feeding. Avoid weed-and-feed products. It’s always better to do the two processes separately.
(Note regarding St. Augustine turf: It might be better to wait a couple more weeks to feed it, since gray leaf spot fungus is most active at high temperatures.)
• Iron additive to correct chlorosis in acid-loving plants. Iron deficiency shows up as yellowed leaves with dark green veins, most prominently displayed on newest growth first. Include agricultural sulfur to keep soil less alkaline. Iron remains water-soluble in acidic conditions.
ON THE LOOKOUT
• Normally we would be approaching prime time (before Labor Day!) to apply pre-emergent weedkiller granules to prevent germination of annual bluegrass, rescuegrass, ryegrass and other cool-season weeds. Options include Dimension, Halts and Balan among others. Also include Gallery granules to prevent germination of broadleafed weeds.
However: because of the ongoing high temperatures and drought that most of Texas is facing, you can slide the application date back by at least one week. Let’s meet again here next week at this same place and resume this discussion. (I know I’ve mentioned this two other places this issue. That’s because I’ve been asked in 40 other places in the past week.)
• Fall webworms. If you are seeing their unsightly webs developing in your pecans, walnuts and other large trees, prune them out as soon as they start to form. Use long-handled pole pruners and drop them to the ground. Gather and destroy them. Spraying is not efficient, nor is it effective.
• As you are working around your shrubs and in fallen leaves, keep a sharp eye out for stinging caterpillars, wasp nests and snakes. They’re all out there. We came upon a fully grown copperhead last week. Human encounters with these are more common in fall than at other times of the year. It’s the wise gardener who heeds the warning.