Plant Carrots for Fall Harvest
Plant carrots in late July for harvest in late September and early October. Select quick-maturing or "baby" varieties such as 'Mokum'. Fall harvested carrots are especially sweet as their starches turn slowly to sugars as the weather cools.
Finish Fertilizing Roses
Give your roses their last feeding of the season with a dose of a complete soluble fertilizer by the end of July. Fertilizing later will keep the plants growing actively into the fall too long and they'll be more likely to suffer winter injury.
Now is a good time to take cuttings of tender plants in the outdoor garden, such as geranium, coleus, begonia, bloodleaf, Persian shield, and alternanthera, to carry over the winter indoors.
Divide Crowded Bearded Iris
Renovate an overcrowded planting of bearded iris by cutting back the tops to 6 inches. Then use a digging fork to loose and lift the entire clump. Cut the rhizomes into 3-4 inch sections with a sharp knife, making sure each section has at least one fan of leaves and some healthy roots. Replant so the rhizomes are just at the soil surface, spacing them 12 inches apart. Discard the old rhizomes from the center of the clump and any rhizome sections that are soft or borer infested.
Check for Tomato Hornworms
Keep an eye out for voracious tomato hornworm caterpillars on tomatoes, peppers, potatoes, and eggplant. Although they are 3-4 inches long, their green color provides good camouflage and they can be hard to spot. To track them down, look for their black droppings on leaves. Also, if you spray the foliage with water, the caterpillars will wiggle about and give themselves away. Bt and spinosad are low-toxicity, natural pesticides that control hornworms or you can handpick these large, ferocious looking (but harmless to humans) pests and drop them in a bucket of soapy water to drown. Hornworms overwinter as pupae in the soil, so tilling the garden in the fall destroys many of them, reducing numbers the following spring.