Spread Slug and Snail Repellants
Coffee grounds, diatomaceous earth, and even sharp gravel can deter slugs and snails. Spread any of these materials in a ring around individual plants. Wrap pots with copper tape to keep slugs from crawling up. Inspect foliage and squish or pick off any insects that have already passed the barriers.
Keep Tomatoes Evenly Watered
Dark leathery spots on the blossom end of tomatoes is likely to be a condition called "blossom end rot" that's caused by uneven watering. Mulch will help moderate the fluctuating moisture levels that nature provides, and it's not too late to spread some around your plants.
Spend Half Hour a Day Pulling Weeds
Just a half hour ... surely you can find a half hour. Weeds really do sprout overnight and by next week they'll be towering over your zinnias. A visit to the garden before work or as soon as you get home can keep the weeds in check.
Cut Back Flagging Annuals
Pansies, lobelia, petunias, and some other annuals can go into a slump in midsummer. Cut them back and apply liquid fertilizer when you water to rejuvenate them and keep them blooming into fall.
Take Advantage of Discounted Perennials
You can get some great deals on perennials now, and even if you don't have a spot ready for them in the flower border, plant them in the empty spaces in the vegetable garden when you pull out broccoli and other early crops. You can transplant them into their permanent locations in the fall or spring.