Late Summer Gardening Tips: How to Keep Your Garden Thriving into Fall

As summer begins to come to an end, your garden enters a critical phase. Plants may be stressed from heat, pests are at their most aggressive, and you’re balancing harvest with fall & winter preparation. Late summer garden care is all about maintenance, rejuvenation, and forward thinking.

1. Water Wisely

Late summer heat can dehydrate plants quickly but overwatering can be just as damaging.
Water deeply and early in the day to reduce evaporation and avoid fungal issues.
Check soil moisture 2-3 inches down before watering.
Use soaker hoses or drip irrigation to target roots and conserve water.
Group thirsty containers together in the shade to reduce stress.

2. Deadhead and Prune

Many annuals and perennials benefit from a tidy-up.
Deadhead spent flowers to encourage new blooms (roses, zinnias, cosmos, marigolds).
Prune leggy or overgrown plants like coleus, basil, or salvia to promote bushier growth.
For perennials like coneflowers and black-eyed Susans, consider leaving some seed heads for birds.

3. Manage Pests and Diseases

Late summer is prime time for garden pests.
Watch for hornworms, aphids, and squash bugs. Handpick or use insecticidal soap as needed.
Keep an eye out for powdery mildew, especially on cucumbers and zucchini. Neem oil or a milk spray can help.
Remove and dispose of diseased foliage, but don’t compost it!
Stuck on a disease issue? Use GardenAI for help!

4. Feed Selectively

Plants are either winding down or gearing up for a fall flush.
Annuals and vegetables: Give a light dose of liquid fertilizer to support late-season growth.
Perennials: Avoid fertilizing now; you don’t want to encourage tender new growth that frost may damage.
Compost top-dressing is a gentle way to boost soil without shocking roots.

5. Mulch and Weed (Again)

Weeds compete for water & nutrients and go to seed fast this time of year.
Apply a fresh layer of mulch (2–3 inches) to retain moisture, cool soil, and suppress weeds.
Pull weeds regularly, especially before they go to seed.
Use grass clippings, shredded leaves, or straw as organic mulch for veggie beds.

6. Refresh Containers

Heat and frequent watering can leave containers tired-looking by August.
Replace spent annuals with heat-tolerant or fall-transition plants like ornamental grasses, rudbeckia, coleus, mums.
Add fresh soil or compost to boost tired pots.
Consider swapping summer flowers with early fall bloomers like asters or ornamental peppers.

7. Tidy and Rejuvenate Beds

A little mid-season refresh can extend the life of your garden.
Remove plants that are done for the season (like bolted lettuce or spent peas).
Re-seed or replant bare spots with fast-growing crops (radishes, arugula, baby greens).
Trim back herbs like thyme and oregano to promote fresh, compact growth.

8. Support Pollinators and Wildlife

Even as the season wanes, native insects and birds still need resources.
Keep planting late-summer nectar sources like echinacea, goldenrod, and bee balm.
Provide shallow water dishes with pebbles for butterflies and bees.
Let some herbs go to flower like basil, dill, and mint blooms feed beneficial insects.

9. Observe and Plan For Fall

Use this transitional time to take notes and plan ahead
What thrived? What struggled?
Use the Garden Manager to upload photos and track notes
Share photos to the Garden Savvy App! iOS | Google Play
Begin thinking about crop rotation and what to plant in fall or next spring
Reference past Hortisketch plans to rotate crops for next season.

10. Looking Ahead

Start planning for fall bulbs for spring flowering
Plant garlic for next year
Consider a crop over winter such as winter rye grass.