• Plant tomatoes now for a fall harvest before frost. Choose selections that can set fruit in high temperatures. Mulch to reduce soil temperature.
• Plant garlic now for spring harvests.
• Sow seeds of cool-weather herbs (chives, parsley, garlic chives, cilantro and dill).
• It is not too late to set out another planting of many warm-season annuals such as marigolds, zinnias, and periwinkles. They will require extra attention for the first few weeks but should provide color during late September, October and into November.
Perennial and biennial plants can be started from seed sown directly into the garden this month or next. Plant cool-season annuals like pansies, violas, calendula, snapdragons, sweet peas and primroses.
• Container grown perennials, shrubs and trees can be planted this month. Always take time to properly prepare the soil by mixing generous quantities of peat moss, compost and processed manure with your existing soil.
• Winter cover crop such annual rye, red clover or hairy vetch can be planted to enrich garden soil.
• If your centipede grass looks too thin or off color, fertilize it with a product such as Sta-Green 15-0-15 Centipede Lawn Fertilizer. Apply according to label directions or using no more than 6 pounds of fertilizer per 1,000 square feet of lawn. Wait until next month to feed St. Augustine lawns. Continue to monitor discolored areas for insects.
• Foliar feed plantings and lawns. Use one or more of the following: fish emulsion, seaweed, Peters 20-20-20.
• If fertilizing shrubs, use slow-release to avoid rapid, succulent growth that can be killed by early frost. Spread it on top of the mulch and water it in.
• Give perennials a light feeding to encourage a bigger fall display of color.
• Lightly fertilize bearded irises, Louisiana irises and Siberian irises early in the month with low-nitrogen fertilizer, such as 5-10-10.
• Everblooming roses may benefit from a fast-release fertilizer.
• Keep blooms and foliage trimmed on herbs to increase production of new leaves. Many herbs self-sow if the flowers are not removed. Dill produce seeds that fall around the parent plant and come up as volunteers the following spring.
• Early in the month, you still have time to groom and shape perennials such as asters and mums. Pinch off loose or unkempt growth with your fingers. This will help maintain the plants’ compact habits and produce more flowers for a great fall show.
• Disbudding (thinning) chrysanthemums (except spray types) produces larger blooms.
• To stimulate new blooms on flowering perennials, trim off the old flower heads of plants such as butterfly bush (Buddleia sp.), orange coneflower (Rudbeckia fulgida), salvia and purple coneflower (Echinacea purpurea).
• Summer blooming shrubs should be pruned for shape after they have finished flowering. Remove any dead or diseased branches.
• Prune dead or diseased wood from trees. Hold off on major pruning from now until mid-winter. Severe pruning now will only stimulate tender new growth prior to frost.
• Cut out old blackberry canes after fruiting and then fertilize and cultivate for replacement canes.
• Prune and fertilize your ever-blooming roses now for a big show of fall flowers.
• Prune your hybrid roses in late August to promote the most fall blossoms.
• Plants that will be brought indoors can be clipped back now.
• Thin submerged plants in water gardens if necessary and any dead, damaged or diseased leaves.
Watch your irrigation system run. Fix clogs, broken or misdirected sprinklers and emitters. Left without repair, you could lose plants during hot weather.
Water the garden early in the day so plants can absorb the moisture before the hot sun dries the soil. Early watering also insures that the foliage dries before night. Wet foliage at night increases susceptibility to fungus diseases.
• Caladiums require plenty of water at this time of year if they are to remain lush and active until fall. Fertilize with 21-0-0 at the rate of l/3 to l/2 pounds per 100 square feet of bed area and water thoroughly.
• Don’t allow plants with green fruit or berries to suffer from lack of moisture… they’ll drop their fruit.
• Strawberries, blueberries and bramble fruits are forming buds for next year’s crop and need the water now to prevent buds from shriveling.
• Check on water needs of hanging baskets daily in the summer. Wind and sun dry them much more quickly than other containers.
• If irrigation nearly put you in the poorhouse this summer, consider xeriscaping (dry landscaping) ideas for next year.
• Continue to watch for insect, slug and snail, or disease damage throughout the garden and take the necessary steps to control the problem.
• For fire ants consider using Logic fire ant control for large areas. Rotenone/pyrethrum or Come & Get It! for individual mounds.
• To reduce the number of pests on your fruit tree for the coming year, pick up and destroy all fallen fruit.
• Bt (Bacillus thuringiensis) is used by many gardeners to protect cole crops from chewing caterpillars.
• White flies are attracted to yellow, so use yellow sticky boards to reduce their populations.
• Release beneficial insects if needed: preying mantis, ladybugs, green lacewings.
• Watch for fungal rose mosaic virus, leaf spots, powdery mildew and other diseases on your roses, warm-season annuals and perennials. Heavily infested plants should be removed and discarded. Treat with a fungicide as needed: Immunox Plus, FL Liquid Systemic Fungicide, Daconil.
• Sample areas of lawn where mole cricket damage occurred during the spring. If treatment is needed, irrigate dry soil twenty-four hours before applying insecticide will help draw mole crickets to the moist soil making treatment easier. Your Co-op store will have recommendations.
• Change the water in your bird bath regularly and keep it filled. Standing water is less healthy for the birds and may become a breeding ground for mosquito larvae.
• One way to get rid of mosquitoes is by using Mosquito Dunks. When placed in ponds, birdbaths or other standing water, these donut-shaped objects release a bacteria that kills larvae. Insect repellents such as Cutter also work well to control them. Simple steps can help reduce the number of these insects around your garden. Empty all sources of standing water such as plant saucers, buckets or old tires. Keep gutters clear so debris does not cause water to collect. Change the water in birdbaths at least once a week. If you have a water garden, add a few goldfish to eat the insect larvae.
• Summer won’t be around much longer, so enjoy the garden while you can.
• Keep your garden journal updated with observations on the performance of your plants, any pest problems, control measures, control results and thoughts about what needs to be done as summer closes to get ready for fall. Make notes of ideas for next year’s garden.
• Plan your fall garden now.
• Keep tall flowers staked or try using tomato baskets.
• Check your local Co-op’s Garden Center for great buys.
• Gather bundles of herbs for drying.
• Prop up branches of fruit trees that are threatening to break under increasing weight of ripening fruit.
• In your water garden keep surface clean of debris to prevent it from sinking to the bottom and fouling the water.
• Keep the weeds pulled before they have a chance to flower and go to seed again. Otherwise, you will be fighting newly germinated weed seed for the next several years.
• Colorful plastic golf tees can be stuck in the ground to mark the location of dormant plants such as spring bulbs or perennials.
• Cut strawflowers intended for dried flower arrangements when the blooms are only half open. Tie small bundles of the flowers together and hang them upside down in a well ventilated place to dry.
• To cool the soil and conserve water, apply a fresh layer of organic mulch around landscape plants, flowers and vegetables.
Summer vegetable gardens should be at peak production. Harvest often for an ongoing supply. Pick vegetables early in the morning on the day you plan to eat them. Keep picking (every other day if needed) so that beans, tomatoes, cucumbers, squash and the rest remain productive. Select okra, eggplants, squash and cucumbers when they’re small and tender. Use sharp clippers or a small knife to harvest them to avoid tearing the vines or stalks. Southern peas should also be picked when tender for best flavor.
• Mowing at the upper end of the recommended mowing height for your grass type encourages deeper roots and better heat and drought tolerance since the grass helps shade the soil to reduce evaporation and maximize soil moisture content. This is a critical area which can help reduce the need for more frequent watering.
• Sharp blades on your lawn mower give you a cleaner cut.
Alternate mowing directions to help prevent ruts from developing.
• Flowerbeds that are drying too quickly may need a new blanket of good mulch. Adding a rich compost and topping it with a good mulch will both feed your plants and reduce evaporation.
• It’s time to divide spring flowering plants such as irises, Shasta daisies, ox-eye daisies, gaillardias, cannas, daylilies, violets, liriopes and ajugas.
• If you don’t have one, establish a new compost pile for the fall leaf accumulation.