As you remove vegetables that have finished producing, use the space to sow beets, radishes, turnips, chard, spinach, arugula, lettuce and even peas in their place. A single layer of floating row cloth over the new plantings will provide shade, which is welcome on the hot days of August. Always keep seedlings well watered; they have very shallow roots.
It’s a great question, and the answer is simpler than you think. If your hydrangeas bloomed in June and are pretty much finished now, prune immediately. These plants are blooming on “old” wood — last year’s new branches. Cut the stems that had blooms down close to the ground. Leave others to continue to put food into the roots. New branches will begin growing quickly and will set buds before winter (which is why they may not bloom at all if we have a very hard winter). Hydrangeas that do not bloom until August or later are blooming on this year’s new wood. Do not trim them back until late in the winter (March) because they will set their buds on the new wood next year---making them later, but more reliable bloomers after bad winters.
Oakleaf hydrangeas (our only native hydrangea) also blooms on old wood so cut them back as soon as blooming is finished, for most of us that is soon.
Finally, if you have “endless” blooming hydrangeas, deadhead throughout the summer, cutting the stem just a couple of inches below the spent flower For maximum flowers, do not prune the stems back to the ground until it has been growing in your garden for two or three years. At that time, the plant will benefit from new wood.
...watering may be needed in containers where limited room and exposure to heat and sun from all sides mean they dry out quickly. Check containers by wiggling your finger down in until you reach the second knuckle looking for wet soil. If it is dry, water until it comes out of the bottom of the container. And never leave pots sitting in water-filled saucers as this can lead to root rot.
If you are planning to go away for any period of time this summer, remember new trees, shrubs and perennials will need regular, deep watering throughout the summer and fall months to establish good root systems. Consider setting up drip hoses on timers or use ‘tree gators’ to ensuring the water continues to get where it is needed. Use rain gauges attached to the system to prevent wasting water (and overwatering plants) if we continue to get regular rains.
If you're going away on vacation this month, be certain your new plantings will get adequate water.
Empty water from saucers under plants after rains. It’s never a good idea to allow a plant to sit in even a small amount of water. Clean and refill birdbaths every two or three days. Empty anything else that may have sat out in the rain and collected water. Mosquitoes take just a week to go from egg to hungry biter. Also, the rains have washed nutrients out of the containers you planted in May. Adding a diluted liquid fertilizer will ensure that your plants keep growing/blooming into the fall. The more recently planted the container, the less likely you will need additional feedings. Many gardeners prefer weekly doses of diluted liquid fertilizer to the long-term pellets. That way you get to base the amount of food you give the containerized plants on the recent growing conditions.