August Garden To Do List

August 1, 2021

The hot temperatures of mid summer make it tough to spend much time working in your garden, so take advantage of any cooler days to take care of grooming and weeding. In August, the main concern is making sure your garden gets plenty of water. The warmer weather will cause weed seeds to germinate and grow faster, so weed control is another important task this month.


General garden care

  • Fall is the best time to test your soil so that amendments can be added prior to winter weather.
  • Check bird baths for adequate water for both birds and insects.
  • Add mosquito dunks to standing water.
  • Watch the weather. Plants need 1″ of water every week. Set up drip irrigation for slow watering twice a week.



  • Caryopteris will be showing first blue blossoms.
  • Plant garden borders and rock gardens with Daphne stonecrop (Sedum sieboldii, Sedum spurium ‘John Creech’ or other varieties available at garden centers.
  • Check on your dahlias and stake them as needed.
  • Deadhead perennials as needed.
  • Trim back Joe Pye weed for more fall blooms.
  • Start to trim down Silphium stalks as the flowers disappear. Make sure seeds are left for the birds, especially goldfinches.
  • Shop for shrubs, trees and perennials now. Fall is the best planting time and as the season ends, many plants will go on sale.
  • It wouldn’t hurt to fertilize roses now for fall blooming.
  • Purchase tree guards for trees and shrubs. Vinyl tree guards or fencing works fine.
  • Divide perennials. Wait until September or October for hostas and peonies.
  • Check for powdery mildew and spray with a fungicide if required.



  • Plant lettuce, radishes and other greens for a fall harvest.
  • Plant a buckwheat cover crop at empty spaces and “Nemagone” marigold seeds where next year’s tomatoes will be planted.
  • Raspberry harvest should be starting. Keep a watchful eye so you can beat the birds.
  • Harvest tomatoes, beans, squash, kohlrabi, peppers, onions, eggplant and cucumbers. Make pickles!
  • Little melons starting to show and some could be harvested if ripe. Most ripe melons will separate from the vine easily with a gentle “push” against the stem.
  • Harvest garlic if not done last month.
  • Harvest sweet corn and fertilize if tassels are showing.
  • Plant carrot seeds and winter squash seeds for a fall harvest.
  • Harvest beets and plant more seeds for a late fall harvest.
  • Weed around blueberries and corn if not heavily mulched.
  • Check strawberries daily and harvest before the birds do it for you. Make sure they are absolutely ripe as they will not ripen further once they are picked.
  • Leave some artichokes on the plants for their stunning, bright blue flowers (an unusual color in your garden).
  • Plant kale seeds for fall harvest. The colder it gets, the sweeter the leaves.
  • If container cherry tomato vines are looking “ratty”, cut them down and plant some lettuce or other greens for fresh salads in the fall.
  • If you are composting stalks and vines from spent vegetables, make sure they are chopped or shredded well. This will cause them to decompose faster.
  • Plan your crop rotation for next year’s season.
  • As you harvest your crops, if you are not going to plant a cover crop, add plenty of compost for protection over the winter. This will insulate the soil and keep soil organisms “working” for a longer period of time. Chopped and shredded leaves also provide excellent cover and will break down over the winter so spring planting can begin with no labor.
  • Prune your herbs now if they are getting out of hand. Catnip, rosemary and basil especially so they don’t flower.
  • Check your asparagus bed for weeds and add mulch if required.
  • Check your compost. It could use turning this month and make sure it is kept damp-not dried out.
  • Fertilize strawberries at the end of the month with 5-10-5 or 5-10-10.
  • Harvest potatoes when foliage dies back.


Lawn care

  • Plant grass seed starting the 15th of the month. This is the best time of the year to seed or overseed.
  • Buy corn gluten meal now for fall application. It will not only fertilize but also will stop fall weed seeds from germinating. Do not apply if you plan to plant grass seed; it will prevent germination. Wait until next April.
  • Continue mowing at a higher cut.
  • Biological grub control can be used now if necessary.
  • Dethatch the lawn if you are planning a fall lawn renovation program.