Plant Fall-Blooming Perennials
Late summer is a good time to plant fall-blooming perennials such as asters, hardy mums, and 'Autumn Joy' sedum . These plants will bloom from August through the first hard frost.
Divide Bearded Iris
Divide and transplant bearded iris using the vigorous ends of the rhizomes. Discard the old center portion. Cut the leaves back to about six inches.
Recycle Those Golf Tees
Colorful plastic golf tees can be stuck in the ground to mark the location of dormant plants such as spring bulbs or perennials.
Harvest Vegetables Regularly
Harvest veggies as soon as they're ready. Green beans need picking daily; smallish summer squash taste best; pick cucumbers when they are only 4 inches long and they won't taste bitter.
Watch for Powdery Mildew
Powdery mildew is a common late-season problem and often attacks my roses, zinnias, and summer squash plants. I try to minimize the disease by spacing plants well apart to encourage good air circulation. If you find evidence of powdery mildew on your plants, mix 1 teaspoon of baking soda and 1/4 teaspoon of vegetable oil in 1 quart of warm water and spray the mixture directly onto the infected foliage every few days. Keep debris raked from under plants to discourage further infection.