Gardening This Weekend: July 20, 2017
My good friend, the late Dr. Sam Cotner, one of our state’s most admired horticulturists, used to say, “Your garden needs to see your shadow.” Obviously, that was his way of telling us that we needed to get off our couches and head out to check on our plants. Here are things I’d suggest you do this weekend.
• Crape myrtles while they’re in bloom in nurseries. 2017 has been a great year so far, but supplies and selection will shrink as the weeks pass. This is the best time to make your decisions. Here is a list of the best types by color and size.
• Annual flowers and foliage that can handle the heat to brighten up drab spots in your gardens. I have five of the best sources of foliar color in this week’s issue.
• New lawngrass from sod, plugs or seed (bermuda only). Be sure sod or plugs are fresh and vigorous. Plant lawn immediately, then water daily for 5 to 10 minutes to help it get started. After two weeks, water once daily, then increase days between waterings, and water more deeply.
• Perennials to remove spent flower stalks and browned foliage.
• Oak trees as needed. The oak wilt fungus is not active in the hottest summer weather, so this is an acceptable time to trim them. Seal all cut surfaces with black pruning paint.
• Tall grass becomes weak grass. Keep mowing lawn at same height. It is a mistake to think that the grass will be healthier if you raise the mowing height.
• Iron-deficient plants (yellowed leaves, dark green veins, most prominent on newest growth first) with iron/sulfur additive. Keep iron off masonry surfaces that could be stained.
IMPORTANT NOTE: Many of our fast-growing shade trees will have yellowed leaves over the next several weeks of hot and dry weather. But they’ll be the older leaves, farther down on the stems. That will be due totally to water stress. Don’t confuse it with shortage of iron.
• Bermudagrass if it’s been longer than 8 weeks since the last feeding. Wait to fertilize St. Augustine until early September to lessen chance of gray leaf spot outbreaks. See last week’s story on gray leaf spot for more details.
• Container plants with timed-release fertilizer every three or four months, and also high-nitrogen, water-soluble food each time you water.
ON THE LOOKOUT
• Chinch bugs causing dried and dead spots in sunny parts of St. Augustine. Check edges of dying grass for presence of small, black insects with irregular white diamonds on their wings. Treat with turf insecticide.
• Poison ivy in beds or climbing tree trunks. I have this information on my website.
• Lacebugs continue to turn leaves of Boston ivy, pyracanthas, bur oaks, sycamores, azaleas and other plants tan. You’ll see their black droppings on the backs of the leaves, but you probably won’t be able to see the pests themselves. Most insecticides will control them, but systemic insecticide applied in early summer will prevent this damage from showing up in the first place.