Renew, refresh, and revitalize the late-summer garden
Story and Photography by Richelle Stafne
It’s been a long, hot summer. We could all use a spa day. Even our gardens could benefit from some renewal, refreshing, and revitalization. For some, late summer means August and for others, it’s late August through early September, even though it may feel like summer until October.
Summer annuals and tender perennials such as Impatiens and Begonia can become very leggy by summer’s end. This can occur from planting them too close to one another or other bedding plants. As summer wanes, continue deadheading to encourage floral production. Deadheading also keeps plants tidy, removes unsightly fading blossoms, and can increase air circulation around the plant, reducing disease.
Competition forces the plants to become tall and spindly as they reach for light; thus foregoing side leaf production for a few leaves near the top. If you enjoy plant propagation, many of these leggy growths can be pruned, rooted, and kept in a greenhouse until the following spring, or planted this year on new roots, which is especially worthwhile if plants are perennial or tender perennials.
For dramatic seasonal change, remove spring and waning summer annuals and plant for fall color in late summer using plants such as annual marigolds (Tagetes spp.), perennial Gaillardia, and fall aster (Symphyotrichum oblongifolium). If you are itching for cool weather, start preparing garden beds for the change to cool-weather species such pansies (Viola x wittrockiana), snapdragons (Antirrhinum majus), Dianthus, and ornamental cabbage and kale.
Prune vines or aggressive growers such as Asiatic jasmine (Trachelospermum asiaticum) and Vinca minor. Aggressive vines such as these make great borders along walkways, but need to be pruned a couple of times a year. Pruning helps them provide a sharp, defined edge for walkways and borders.
When late-summer weather is hot and dry, raise those mower blades. Heat plus drought is stressful enough on lawns, but mowing so low as to remove most of the leaf blade area from the lawn exposes it to the intense heat and light of the sun, drying out the soil and desiccating lawn grasses. A stressed lawn is more susceptible to insect and disease pests.
Encourage floral production of established Wisteria by spur pruning to within 6 inches of the main branches (think grapevines!). This increases the lateral growth and should be repeated in early to mid-winter while the plant is dormant.
Determine space, purchase seed, and prepare the soil for planting wildflowers for pollinator gardens. If neighbors have an established pollinator garden, they may have seed to share. Likewise, if you are adding spring-flowering bulbs to your garden, prepare the soil now for fall planting.
Be sure that growth of large shrubs and trees has not shaded out sun-loving flowering plants. Head out into the yard on a sunny day to evaluate the level of light flowering plants are receiving. Make notes about flowering plants that need more light and then research appropriate timing and pruning methods for those larger trees and shrubs.
Rejuvenation pruning can be done before mid-September for some overgrown shrubs and hedges such as oleander (Nerium oleander), boxwood (Buxus spp.), Photinia, etc. Leggy, overgrown shrubs may not be producing many flower buds after years of unchecked growth. In general, prune flowering shrubs immediately after blooms fade to avoid removing next year’s flower buds. However, with rejuvenation pruning, your goal is to reduce a shrub’s growth enough to encourage an entirely new flush of growth from the base of the plant. Be sure these severely pruned shrubs have time to harden off to avoid winter injury.
Continue pinching Chrysanthemum until July 15 for the best fall flowers on low, bushy plants.
Refresh mulch beds to suppress weeds, retain soil moisture, and add a crisp, finished look to the landscape. Over time organic mulches break down (great for soil building), get washed away (rain and irrigation systems), or blown away (mowers and blowers).
Revitalize soil by side-dressing plants with compost. Areas that were amended with compost this past spring can benefit from another addition now. Massage compost into soil where fall vegetables will be planted. Avoid fertilizing plants that will soon enter fall dormancy. A new flush of growth on these plants is very susceptible to damage by winter temperatures.
Grow plants known for late summer blooms, such as naked ladies (Lycoris radiata), Autumn Joy sedum (Hylotelephium ‘Herbstfreude’), and white butterfly gingers (Hedychium coronarium). These plants can perk up a tired summer landscape with floral displays in late summer and early fall. Add plants with flowers and foliage in “autumn colors” to seasonal beds and containers, such as the nearly black Illusion Midnight Lace sweetpotato vine (Ipomoea batatas ‘NCORNSP-011MNLC’). Native grasses, such as pink muhly grass (Muhlenbergia capillaris) and northern sea oats (Chasmanthium latifolium), delight with fall flowers and seed heads peaking late summer into fall. Your garden will thank you for a late-summer spa day!
LATE SUMMER CHECKLIST
• Deadhead flowering plants to encourage continual flower development. Pinch herbs before flowers are set to promote continued leaf production.
• Apply a fresh layer of mulch to landscape beds.
• Side-dress garden and landscape plants with compost.
• Remove non-productive garden vegetables and prepare beds for fall veggies.
• Begin to pull areas of colorful seasonal annuals to make room for fall annual plants.
• Trim vines from sidewalks and walkways.
• Edge landscape beds for a more manicured look.
• Work on landscape plans to prepare for fall-planting of trees and shrubs.