Temperatures really begin to heat up in June -- and that typically marks the end of the planting season in this region. But continue to check out clearance sales for garden plants -- there are often good deals to be had!
Be sure and add organic matter to your soil as you plant -- it will improve your ground over time and help get your new plants off to a great start.
Watch your lettuce and other cool-season vegetables; they tend to bolt, or send up a flowering stalk once it gets hot. Once they bolt, they're usually too bitter to eat. It's probably too hot to sow new lettuce seeds in the sunny garden, but you may be able to get a small crop if you plant in the shade.
Or, replace cool-season vegetables with warm-season crops such as beans, pumpkins, squash, and corn.
Test Garden Tip: If you're growing corn, carrots, or beans from seed, you can extend your harvests by planting a handful of seeds every two weeks. That way you can enjoy the produce over a period of weeks instead of all at once.
Unless your area experiences unseasonably cool, moist conditions, your spring-blooming bulbs' foliage should be yellowing. Add the leaves to your compost pile once they have turned yellow and pull out of the ground with no resistance. Don't remove the leaves before this, however -- otherwise your bulbs may not perform as well next year.
If you haven't already mapped out your garden's spring bulb display, do so now. That way you can know exactly what bulbs you'll want to purchase this fall and where to plant them so they'll look good next spring.
Heat-loving summer bulbs are coming into their own. If you haven't planted any yet, get them in the ground now.
Watch for signs of garden pests -- if you catch them early, you can usually keep them from becoming an epidemic that ruins your yard.
Watch your tomatoes for spotted leaves -- pull them off the plant and throw them in the trash as soon as they develop. This may stop diseases such as early or late blight from sucking the life out of your plants so you can enjoy greater harvests.
Lacebugs are a big problem on azaleas, though you don't usually notice the damage until August or September. But now's the time to attack them. Look at your azalea's leaves for black spots on the bottoms and the black-and-white insects on the leaf tops. Spray with neem oil, insecticidal soap, or a similar product to keep them in check.
Examine junipers, birches, cherry and arborvitae for bagworms and other leaf-eating caterpillars, then treat with Bacillus thuringiensis as needed. Keep an eye out also for aphids and other small sucking insects, as well as whitefly. Spider mites can be treated with pyrethrums, an extract from mums.
Keep an eye out for containers of standing water in your garden -- they may be breeding grounds for mosquitoes. Change the water in your birdbaths daily and use environmentally friendly mosquito-control products in water gardens.
This is a good month to take cuttings from the fresh growth of many trees and shrubs, including serviceberry, lemon verbena, chokeberry, angel's trumpet, bougainvillea, butterfly bush, hydrangea, jasmine, dogwood, magnolia, and stewartia.
Your grass will grow faster as temperatures climb, so mow regularly. Avoid letting your grass grow too long; it's best to cut less than one-third of the total length of the leaf off at one time.
If grubs were a problem last year, you may need to treat your lawn for them. While May is the ideal time, you can still apply a grub killer in early June.
If you water your lawn during dry spells, be sure to water deeply. It's best to let the water soak into the soil rather than watering frequently so only the top of ground stays moist.