Gardening This Weekend: June 19, 2025

I promised you my own personal checklist of the most critical tasks for the second half of June. Here’s what we’re doing around our landscape and garden.

PLANT
• New turfgrass anywhere that it’s needed. St. Augustine and bermuda, our two most popular warm-season grasses, thrive in hot weather. Your main goal will be to keep the new plantings watered daily until good roots are established – probably 2-3 weeks.
• Heat-tolerant annual color from trailing lantanas, purslane, moss rose, Cora XDR vinca, angelonias, pentas, fanflowers, purple fountaingrass, Gold Star Esperanza, firebush, and many others. Buy transplants that have been acclimated at the nursery to summer conditions.
• Crape myrtles while plants are in full bloom. Buy color and mature size to match your landscape needs and space.
• Fall tomato seeds to start transplants in pots. You can also root tomato cuttings from your spring plants. Your goal is to have transplants ready to set out into your garden by early July.

PRUNE
• Daylilies and other spring- and summer-blooming perennials can be trimmed as soon as they finish flowering to remove old floral stalks, seedheads.
• Erratic and winter-damaged twigs and limbs from shrubs and shade trees.
• Pinch growing tips out of mums, copper plants, fall asters, coleus, begonias and other plants that try to become too leggy. Tip-pruning causes them to send out side shoots.

FERTILIZE
• Patio pots and hanging baskets with a diluted solution of a high-nitrogen, water-soluble fertilizer weekly.
• Bermuda turf with high-nitrogen fertilizer that has 30 to 40 percent of that nitrogen in slow-release form, but avoid applications of any nitrogen to St. Augustine until September to lessen chance of gray leaf spot outbreaks.
• Trees, shrubs, groundcovers and annuals with high-nitrogen or all-nitrogen fertilizer to promote sustained growth and vigor through rest of growing season. It’s best to do it now rather than in several weeks after it’s been really hot and possibly dry for a prolonged period.
• Iron-deficient plants (yellowed leaves with dark green veins, most prominent on newest growth first) can be treated with iron additive with sulfur soil acidifier to help reduce alkalinity of soil. Keep iron products off masonry and painted surfaces that could be stained.

ON THE LOOKOUT
• Spider mites on tomatoes, cucumbers, squash, marigolds and many other plants. Damage will first be visible in lower leaves, then they will flush upward into the rest of the plant. Thump a declining (not dead!) leaf over a sheet of white paper. Look for the nearly microscopic specks to start moving around. Those will be the spider mites, and they can spread from species to species. Apply a general-purpose insecticide that lists spider mites on its label. Re-inspect weekly. Repeat as needed.
• Gray leaf spot causing yellowed “washes” across St. Augustine turf. Sun or shade. Exacerbated by applications of nitrogen in hot weather, so avoid nitrogen and apply labeled fungicide such as Azoxystrobin.
• Chinch bugs causing dried looking areas in hottest, sunniest parts of your St. Augustine lawn. You will be able to see the small, black insects with irregular white diamonds on their wings if you part the grass with your fingers. Apply labeled insecticide. They can quickly kill affected areas.