Prevent Powdery Mildew Disease
To avoid powdery mildew disease on roses and apple trees, thin branches for better air circulation. Keep water off the leaves of begonias and zinnias, and try not to water late in the day. Pick off diseased leaves as soon as you notice them.
Plant strawberries now and mulch with straw to keep weeds down and prevent soil from splashing onto the fruits. Strawberries grow best on raised beds in sandy loam soil amended with compost. Plant in double rows and be careful not to plant the crown too deeply.
If you're transplanting seedlings in peat pots, be sure to bury the entire pot, including the rim. If the rim is above the soil level, it will act as a wick and draw moisture away from the transplant. As an extra precaution, you can break away the bottoms of peat pots as you plant them to ensure the roots penetrate into the soil.
Apply Organic Mulch
Add a 2- to 3-inch layer of mulch around trees, shrubs, and perennials to help retain soil moisture and prevent weeds from cropping up. Organic mulch could include straw, bark, shredded leaves, or compost. Keep the mulch a few inches away from trunks and main stems to prevent crown rot.
Install a drip irrigation system in your vegetable or flower garden to help conserve water. Drip irrigation eliminates water loss from spray evaporation and surface evaporation. With a drip system you can water more often without causing fungus to grow on the leaves of your plants.