Gardening This Weekend: July 20, 2023
Here are the things I’d deem to be most critical for this second half of July. We’ll save the strenuous digging and lifting for a cooler time of the year.
PLANT
• Fall vegetable crops. It’s too late for tomatoes except in South Texas or unless you’re going to grow them in large pots in a greenhouse. Plant peppers now.
• Heat-tolerant color, including pentas, angelonias, fanflowers, gomphrenas, vincas, lantanas, copper plants, firebush, purple fountaingrass and for shade, coleus and wax begonias.
• Quick tip: If you want “instant color,” buy an attractive hanging basket and repot it into a large patio pot. It will look like it’s been there all season.
• Crape myrtles are still in flower in nurseries. Choose a color that will look best with everything around it (including your brick and trim). Choose a mature plant size that will fit its surroundings. Choose carefully to avoid “emergency” pruning later.
• New turfgrass. You want the grass to be well rooted before fall’s cooler weather. You have only a few weeks left. Water lightly morning and evening until it roots into the existing soil, generally after 1-2 weeks.
PRUNE
• Errant and unwanted shoots on shrubs. Try to avoid formal shearing into unnatural shapes, however.
• Dead and damaged branches from trees so they won’t break and fall into your house and landscape. Oaks and other trees that sustained damage in the freeze of February 2021 should be pruned by a certified arborist – someone who is insured and experienced.
• Mow your lawn at the recommended height. Raising the blade does not improve its survival in hot weather, regardless of claims you may see or hear. Grass that is maintained taller than recommended will thin. Weeds will develop and the sun will hit the bare ground as well.
FERTILIZE
• Patio pots and hanging baskets with water-soluble, high-nitrogen fertilizer to replenish nutrients lost by the frequent waterings.
• Bermuda turf with a high-N or all-N lawn food if it’s been more than 8 weeks since last you did so. Do not fertilize St. Augustine, however, until September. Nitrogen promotes gray leaf spot fungus in St. Augustine during the summer.
• Iron and sulfur to plants showing iron deficiency (yellow leaves with dark green veins, most prominently visible on youngest leaves). Sulfur is applied to reduce the soil’s pH (alkalinity) so that iron will remain soluble for uptake by roots.
ON THE LOOKOUT
• Webworms attacking pecans, persimmons, walnuts and a few other types of trees. They begin at ends of branches and quickly form large webs that shroud large parts of the branches. Use a pole pruner to clip them off just as they are beginning. Sprays are difficult and not efficient.
• Bagworms came along a bit later this year. They devour needles from junipers, arborvitae, cypresses and a few other conifers. Spray with B.t. or other listed insecticide while they are still feeding actively. Once they tie themselves off to the plants’ twigs all you can do is pull them off by hand.
• Leafrollers folding leaves of pyracanthas, cotoneasters, redbuds, trailing vincas, sweetgums and cannas together. Systemic insecticides such as Imidacloprid will stop them if applied 30-45 days prior to their active feeding. You may have to start earlier next year.