Keep Frost Protection Handy
Although there will be glorious warm days, there also will still be chilly ones -- and nights as well. Keep a variety of frost-protective devices available, such as clean, dry straw, portable cold frames, clear plastic plant "umbrellas," hot caps, and specially designed frost-protective fabric. When all else fails, an old sheet or cardboard box works. Strawberries are most vulnerable at this time of year, but tender new rose growth also is susceptible. Most spring-blooming plants are hardy enough to withstand light frosts, but for special plants, it's better to be safe than sorry.
Visit Garden Centers
Garden centers are getting in new shipments every week, so stop by periodically to see what's new and wonderful. Be adventurous and try some plants this year that are new to you. More and more native trees and shrubs are becoming available, so look for these. If you don't see what you want, ask, because full-service garden centers usually want to provide the best possible service to their customers. If the garden center doesn't have reference books available, take a favorite plant encyclopedia along with you so you can make an informed decision.
Feed and Mulch Perennials
Finish cleaning up around perennials, removing any dead or damaged parts. Summer- and fall-blooming perennials can be divided now, but hold off on the spring-blooming ones until after flowering. Be ruthless with overgrown plants, removing any that have outgrown their allotted space. If you can't stand to throw them away, then pot them up to give to friends. Remove weeds and fertilize with composted dried manure or a complete fertilizer, such as 5-5-5, digging it into the top several inches of soil. Mulch with a 2-inch layer of finished compost or partially decomposed hardwood mulch.
Continue Planting Spring Vegetables
Direct sow lettuce, greens, radishes, and peas, choosing heat-tolerant varieties as much as possible, as the weather in our region quickly goes from cool to hot. Cole crop transplants as well as leeks and onions can be planted now. Choose day-neutral onion varieties, if possible; the variety 'Candy' is easy to grow and sweet-tasting. When noon temperatures average 45 degrees F, sow spinach, parsnips, carrots, and beets. Repeat plantings in two weeks. As beets grow, thin them, using the tops in salads or as cooked greens.
Acclimate Houseplants to the Outdoors
Although the last frost is still officially several weeks away, you can begin to acclimate your houseplants to the outdoors by taking them outside when the weather is predicted to be warm, both day and night. The downside is that they'll have to be taken back indoors when frost might occur. Prevent sunburn on the leaves by placing the plants in a partially shaded spot at first. Keep the plants well watered, fertilize them, and treat for any pests. Houseplants that summer outdoors grow and thrive better than ones left indoors all year. They also make attractive additions to container groupings on decks and patios.