SeasonTips & Tricks

August Gardening Tips

Sunny Gardens vegetables summer 2019


If you plan to do some landscape planting this fall, now is a good time to decide on the plants to use and how to arrange them. Start selecting your favourite bulb varieties now by searching out bulb catalogues. It is time to order so bulbs can be planted this fall. Order your spring-flowering bulbs now. A good guideline to use is ‘biggest is best’ in regard to bulb size. Be careful about so-called “bargain” bulbs as they may be small or of inferior quality. Plan changes in your perennial plantings now. Autumn is usually the best time for moving and dividing perennials since the gardening pace has slowed considerably. Add new bulbs to your design at the same time. Peonies, bleeding heart, and oriental poppies grow better if left undisturbed, so plan to work around them.

Sunny Gardens | August Gardening Tips
Sunny Gardens | August Gardening Tips

By the time the seed catalogues arrive in January, you may have only a vague idea of what this year’s garden was like. Make notes now so you can have a better garden next year. Order peony roots now for planting in September. Plant about a month before the average first frost date in your area. Planting should be completed before the first killing frost occurs.


Sow seeds of cool weather crops such as carrots, parsley, radishes, Swiss chard, lettuce, and beets. Sow perennial seeds: Shasta daisy, coreopsis, columbines and black-eyed Susan. Fall vegetables can be planted now. You can also start to plant seedlings of cabbage, cauliflower, broccoli, Brussels sprouts. Late-blooming perennials, such as Helianthus, Helenium, Heliopsis, and Rudbeckia, make great colour displays in the fall landscape.

Sunny Gardens | August Gardening Tips
Sunny Gardens | August Gardening Tips

Plant autumn-flowering crocus, sternbergia, colchicum, and other fall-flowering bulbs as soon as they become available at garden centres. Crocus and sternbergia need full sun; colchicum can be planted in areas receiving light shade.


Feed summer annuals and container plants with a complete fertilizer like 20-20-20 or 5-5-5. Shear tops off ragged-looking petunias, feed again and water regularly. They will flower again within four weeks
Pick up fallen and decaying fruit that could harbour insects and diseases. If fruit looks infested toss in the garbage, you don’t want to add diseases or insects to your compost pile. Give spring-flowering shrubs their final feeding of the year. Harvest fruit and vegetables regularly. Now is a good time to sow fall-winter flower seeds. Calendulas, Iceland poppies, primrose (English, fairy or Obconica), pansies, violas, snapdragons, stock or forget-me-nots. Keep feeding chrysanthemums until their buds swell and begin to open. Add a new layer of mulch or organic matter such as ground bark, compost, grass clippings, or leaves to keep down weeds and help hold in moisture. Prepare fall planter beds by cultivating the soil at least 12 inches (30 cm) deep, then work in a 2-3-inch (5-7.5 cm) a layer of organic matter or compost, with a small amount balanced fertilizer. Feed rose bushes with a complete fertilizer for final fall flowering and make sure they get plenty of water during the hot weather.
Dig, divide and replant bearded iris rhizomes and Oriental Poppies. To maintain a healthy lawn and reduce the potential for water contamination, it is important to fertilize at the right time. Fertilize cool-season lawns (Kentucky bluegrass, fescue, ryegrass) in the fall. Fertilize warm-season grasses (bermudagrass, zoysiagrass, centipedegrass) in the summer.
When watering lawns during hot weather, do it early in the morning.

Sunny Gardens | August Gardening Tips
Sunny Gardens | August Gardening Tips

Otherwise, much of the water will evaporate from the grass before the plants get to use it. To further avoid excess evaporation, use a sprinkler that produces large drops of water instead of a fine mist. Remove old or faded rose flowers and hips. Comfrey makes a great addition to the compost pile. Its succulent, green leaves are rich in nitrogen that aids in the break down of dry material in the compost pile.
Herbs can still be harvested and used for a multitude of purposes. To keep your gardens attractive, continue to dead-head (trim off) spent flowers and weed as necessary. Check hose connections, pipes, and valves for water leaks. Even a small dribble can waste hundreds of gallons of water in a day. If you do not have a cold frame, now is a good time to build one. Keep newly planted trees and shrubs well watered. Clean up fallen rose and peony leaves. They can carry diseases and insect pests over the winter if allowed to remain on the ground.

Weed and Pest Control

If budworms are eating the flower buds of petunias or geraniums spray plants every 7 – 10 days with Bacillus thuringiensis. Control tomato hornworms, handpick the worms off or spray Bacillus thuringiensis. Water your plants several hours before applying pesticides, especially during dry weather. Drought-stressed plants have less water in their plant tissues and the chemicals that enter the leaves consequently will be more concentrated and may burn the leaves.

All those jobs can be done by Sunny Gardens, just contact us for details of garden maintenance, landscaping and design.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.