Photo by Jennifer Martiné
In this wine-colored fall container garden pops of icy blue contrast the warm combos of bright pinks and deep purples.

What to do in your garden in August

Jim McCausland  –  Updated February 27, 2019


Autumn crocus. Sunset climate zones 2-7, 17: Buy corms of autumn crocus (Colchicum) as soon as they appear in nurseries and garden centers. Pot them or set them out in filtered shade under deciduous trees. Their lilac purple, pink, or white flowers open on leafless stems in late August. The foot-tall leaves emerge in winter, then fade away as summer heats up.

Containers. Brighten an entry or patio by filling containers with flowers like the ones listed for fall and late-summer color below. To reduce irrigation, mix water-storing polymer- or starch-based granules into the potting soil at planting time. The absorbent granules act like tiny sponges that hold water around roots until they need it.

Fall color. Nurseries still have potted asters, chrysanthemums, and dahlias (mostly miniatures) for sale. Plant now for autumn color.

Fall crops. Zones 4-7: Plant beets, cole crops (broccoli, cabbage, collards, kale, kohlrabi), leeks, lettuce, onions, peas, radishes, and spinach.

Garlic. Zones A2, A3: Extra-hardy hardneck types like ‘Music’ grow well in Alaska if you plant cloves before mid-August and cover the bed with 1 foot of straw mulch after the first hard freeze. Good sources for ‘Music’ are Seeds of Change (888/762-7333) and Territorial Seed (800/626-0866).

Late-summer color. Zones 4-7: As you remove early-blooming flowers from beds, fill the empty spaces with summer bloomers you find in nurseries. Good candidates include calibrachoa, marigolds, pelargoniums, and petunias for sunny spots; coleus and impatiens for shady places.


Make compost. If you don’t have one already, now’s a good time to start a compost pile. To hold the compost, join four 4- by 4-foot square wood pallets (the kind used at home and garden centers) at the corners to form a bottomless, open-topped box. Toss in a blend of vegetable scraps from the kitchen (everything from apple cores to carrot tops) and garden waste such as grass clippings and seedless weeds. Water the pile to keep it as moist as a wrung-out sponge and turn it weekly with a garden fork. You’ll have rich compost in a couple of months.

Upgrade tools. Good tools make summer chores faster, easier, and safer. A new supplier that offers only high-quality tools (like Felco pruners, Haws watering cans, and Spear & Jackson forks and spades) is now available on the Internet; check out Garden Hardware Co.