You can still plant annual flowers, herbs, perennials, and fast-growing vegetables like cucumbers and melons. Shrubs and trees can be planted but will require a lot of watering through the summer.
Continue mowing weekly. It is best for the lawn to not cut grass below 3 inches tall. It is also better not to bag grass clippings. Leaving the clippings on the lawn saves work, adds organic matter and nitrogen to your soil, and does not contribute to thatch build-up.
Keep up with the weeding as necessary.
Keep everything watered.
Prune spring-flowering shrubs when they finish blooming.
Garden mums should be cut back to encourage fall blooming.
Check yourself and others for ticks. Here is a great resource in our area for information on ticks and tick-borne illnesses.
Keep your birdbath full but clean it out frequently to prevent mosquitoes from breeding in it. Here are some other mosquito control ideas.
Take time to enjoy the fruits (and vegetables and flowers!) of your labor!