Successful Summer Gardening

by Tina Mast // July - August - September 2019

There is always something to do in the garden during the summer months. With just a bit of planning to keep it from becoming an overwhelming job, you can ensure your garden not only survives the dog days of summer, but also thrives – and you can even have time to stop and smell the roses. Here’s our list of the big-ticket items to check off your landscaping to-do list for the season.


– Help newly planted plants become well-established by making sure their water needs are being met. Water deeply at least once a week if we haven’t had a good rain (an inch or more). Also, mulch, mulch, mulch. A 2”-3” layer of mulch will protect developing roots, conserve moisture, and help prevent soil-borne diseases from spreading. Keep mulch away from trunks and the crowns of plants by tapering it as it goes in towards the plant. (Hint: think “donuts,” not “volcanoes”). Try planting in the evening or on cloudy, cooler days to minimize stress on new plants.
– Need to add some “wow” to your garden? Add color with annuals such as lantana, vinca, coleus, ornamental peppers, pentas, impatiens, zinnias, begonias, New Guinea impatiens, and more.
– Now is a good time to prune trees that tend to bleed sap: maples, elms, dogwood, and birches.
– Pinch flowers off herbs to prevent them from going to seed and to keep the plant’s energy directed to producing foliage. Herbs also taste better when they haven’t been allowed to form flowers.
– Deadhead roses by cutting back to 1/4” above an outward facing leaf containing five or more leaflets. This helps push another round of bloom.
– Now is a good time to transplant houseplants that may have outgrown their pots. Also, if pots have a lot of white salt build-up on them, scrub them down and rinse them.
– Fertilize roses monthly with organic or controlled-release fertilizer labeled for roses. Add in water-soluble fish/kelp fertilizer for micronutrients and top-dress with compost for a great boost that your roses will love.
– Fertilize warm-season grasses every four to six weeks with fertilizer labeled for turf. Don’t fertilize fescue until September.
– Feed container plants, flowering bedding plants, and hanging baskets with fertilizer labeled for blooming plants (either granules or water soluble).
– Bugs will remain numerous and hungry this month. A watchful eye can catch problems before they become difficult to manage. Watch out when spraying chemicals in hot weather. Check labels for temperature ranges and other spraying restrictions such as when to spray to avoid hurting bees or the last day you can spray before harvesting.


– Start planting transplants of cool season veggies such as cabbage, cauliflower, broccoli, Brussels sprouts, and lettuce in mid to late August for autumn harvest. September is almost too late for certain fall veggies, such as broccoli and cabbage, that need long maturation times. Leafy greens and lettuces can be started later and several times, for multiple crops.
– Add glory to your autumn garden with late season bloomers such as Autumn Joy sedum, rudbeckia, boltonia, asters, sages, goldenrod, anemones, ornamental grasses, and more.
– Lightly trim back summer blooming perennials such as coreopsis, coneflowers, bee balm, phlox, and black-eyed Susans to encourage fall bloom. Trimming will also extend bloom season for annuals and is a good way to help them through August’s heat.
– Fertilize warm season grasses such as bermuda, zoysia, and St. Augustine.
– A quick shot of water-soluble fertilizer will revitalize recently trimmed annuals and perennials that have had nutrients washed out of soils with the summer rains.
– Feed houseplants every two weeks, especially if they are summering outdoors.
– Last chance to fertilize those summer veggies!
– Keep mower blades at the highest setting during hot summer months and make sure blades are sharp. Water early in the morning to prevent diseases.
– Water plants as needed, making sure that anything that’s been in the ground less than two years is getting regular water. Generally, one inch of water per week is recommended for trees and shrubs if there has been no significant rainfall, and it can be beneficial to break that up into two separate waterings. Perennial and annual beds may require water more often if dry conditions persist. Vegetables require regular water for best yields.


– Time to plant pansies and garden mums. Pansies should be in by the end of this month for best establishment before winter and can be planted in beds and containers that receive full to partial sun. Give them fertilizer labeled for blooming plants upon planting for bountiful blooms.
– There’s more to fall color than just pansies and mums, though. Good trees for fall color include gingko, red maple, pin oak, and Chinese pistache. Try shrubs such as oakleaf hydrangea, nandina, beautyberry, pyracantha, fothergilla, and Encore or Bloom-a-Thon azaleas. Late season perennials such as sedum, boltonia, asters, and Japanese anemone will add interest to your perennial beds.
– The beginning of the month is your last chance to plant transplants of head-forming cool-season veggies such as broccoli, cauliflower, cabbage, and Brussels sprouts.
– It’s still a good time to grow leafy greens such as kale, Swiss chard, spinach, and lettuce. Seeds of radish, mustard, turnip, beet, spinach, and lettuce can be sown directly into garden beds.
– In general, it’s time to wind down applications of fertilizer. You don’t want to stimulate tender new growth that can get nipped when the first frosts arrive.
– Fertilize cool-season grasses such as Kentucky bluegrass and fescue to prepare them for the season ahead. Choose a good slow-release or controlled-release fertilizer labeled for turf.
– Mid-September through mid-October is prime time to seed new lawns or overseed languishing old ones with cool-season grasses such as fescue/fescue blends or Kentucky bluegrass. Overseed warm-season grasses like zoysia with annual ryegrass for a green lawn through winter. Prep areas to be overseeded by de-thatching and aerating beforehand. Spread seed, roll with a roller to press them into the soil, and mulch lightly. Be sure to keep newly seeded areas well-watered until the grass is up and established.
– Now is a good time to divide and re-plant overgrown or tired perennials. Those that respond well to division include coneflower, coreopsis, daylily, iris, phlox, hosta, lamb’s ear, and shasta daisy.

Tina Mast

Communications director at Homewood Nursery in Raleigh.