Gardening Notes For August

To me, August is the month that epitomizes summer.  The days remain long, with the daytime chant of the cicadas with the evening chorus of the crickets.  With July’s ample rainfall color is ample in the flower garden and the vegetable garden is in full swing.  August typically has more humid days then July, but the temperatures are usually in the 80’s, which is good for both the plants and the gardener!  Continue to take good notes of your endeavors so that you can jog your memory next year for creating a better garden!     

Things to do:

  • Continue to cut the lawn as growth and rainfall permit.  Maintain a higher cutting height of 3”+ to reduce the stress on the turf.
  • The third and fourth weeks of August are the ideal time for reseeding or seeding new turf areas.  The evening dew becomes heavier and helps to ensure proper growth and the warm soils allow proper root development before winter.  Supplemental irrigation is still necessary if rainfall is slight.
  • Make certain plantings from spring and trees planted last year continue to receive weekly irrigation during periods without rainfall. 
  • Many annuals in containers begin to look tired.   For some, a light pruning along with weekly fertilizing and daily watering will breathe in new life.  For others, it is simply time for replacement.  For autumn, consider Salvia leucantha (Mexican Bush Sage) and Leonotis leonurus (Lion’s Ear) as options to the garden ‘Mum’.
  • Although still 2 months away, at months end you may wish to start taking cuttings of some annuals for rooting, potting and over-wintering for next year’s garden.  If rooting fails, there is still plenty of time to get new cuttings.
  • Gather and save seeds of various non-hybrid annuals for seeding next spring.
  • Bush beans, peas or other crops that have finished producing should be removed, the soil amended with compost, and the area replanted with a crop that mature within 70 days or by October 15, the first average date for frost in NJ.  Suggestions for 2nd crops include:

Root Crops

Leaf Crops
Mache (like lettuce)
Mesclun Mixes
Pak Choi
Salad Greens

Broccoli Raab



  • Resist the urge to vigorously prune plants.  Heavy pruning during August and September will result in a vigorous production of new shoots that will not become ‘hardened off’ by the first frost, resulting in not only their death, but potentially the death of the plant!  Removal of broken branches or light pruning/shaping is still healthy for the plant. 
  • Many tree limbs will gradually hang down lower following the flush of new growth.  Removing the lowest tier of branches on a shade or small tree during August often tends to make the Garden look more open and able to ‘breath’ again.  It also allows more light to reach the plants or turf grass beneath the tree. 
  • Near the end of August, leafy crops such as Arugula, Spinach, and Lettuce can be planted as the evening temperatures consistently drop into the 60’s and upper 50’s. 
  • Late August is an ideal time to plant new perennials, shrubs and evergreens in the garden, as the soil is warm and root growth is rapid!
  • Continue to deadhead most perennials, roses and annuals to promote new flowers.  For some, such as Echinacea and Rudbeckia, you may wish to leave the seed heads, since they are a food source for Goldfinches.
  • Cut back Irises and inspect for borer damage in the rhizome.  If the clump is large and root bound, lift, divide and replant during August.  The same is true of Peonies, but be careful to leave the growth buds at or near the surface to ensure blossom production in the years to come.  If the buds are planted too deep, the plants will fail to bloom.