Enjoy all the beautiful blooming flowers—dogwoods, redbuds, crabapples, Halesia, Viburnum (a bunch of varieties kick in now), azaleas and Rhododendron. Around here, the 'Pinxter' piedmont azalea lights up the woods. While you're in the woods (or in your natural garden area), step lightly and keep an eye out for bloodroot, bleeding heart, Jack-in-the-pulpit and, if you are lucky, Trillium. April is truly a month that's both busy and delightful in the garden.
Remember Your Row Covers. Don't put away those season extenders yet. Spread them over plants like laying down a blanket in case the cold returns. You must, however, remember to remove them on hot days.
For Amazing Annuals. Prepare new annual (vegetable and flower) beds by turning compost or other organic material blended with a slow-release fertilizer into the soil. You may also add lime at this time, based on a soil test.
Seed Starting. During the first week or two of April, you can still start warm weather flowers and vegetables indoors, like zinnias, asters, marigolds, sage, tomatoes and peppers. If I don't get them started by then, I just wait and direct seed the flowers in early May.
Temperature Tip. After mid-month, once danger of frost is past, nighttime temperatures are above 10 degrees C (50 degrees F), and soil temperatures are above 15 degrees C (60 degrees F), it's time for tomato and annual flower transplants, and for direct seeding beans, cantaloupe, corn, cucumbers, pumpkin, squash and watermelon. (I wait until May to sow okra, and to transplant peppers, eggplant and sweet potatoes). The 'magic date' around here is April 15.
Tomatoes. Do not plant your tomatoes in the same place year after year Diseases can easily built up in the soil, so make sure to rotate your crops, even on a small scale.
What's Growing? In the vegetable garden this month, you'll have cool season crops (like sugar peas, lettuce and greens) growing strong, even as you sow your Summer crops. Try integrating edibles into 'ornamental' parts of your yard, wherever you have sufficient sun. Remember, the peas make a great 'green manure' for the next crop.
Spring Flower Tip. After spring-flowering bulbs like daffodils have finished blooming, don't cut those leaves! Keep the foliage until it begins to turn yellow. They need those leaves to make new bulbs for next year's flowers. I plant daylilies and other plants with my bulbs, so that the fading leaves are hidden a bit when the succeeding plant begins growing.
Healthy Herbs. Plant herbs after the danger of frost has passed. You can plant herbs directly into the ground or in containers. Basil, an annual, I handle a bit differently—I plant it beside or right in my tomato beds. Purchase clean seed, though— since basil seed has been linked to transmission of soil-born pathogens.
Support Your Perennials. If you have tall perennials, like hollyhocks and peonies, it's time to think of giving them a helping hand with a stake or support. Small tomato cages work for peonies, if you don't mind populist garden art (the leaves hide the wire, anyway).
Feed Your Fruit Trees. It is time to feed your fruit and nut trees, vines and bushes, such as blackberries, grapes, raspberries and blueberries (careful! Blueberries are very shallow rooted). Figs, maybe the easiest fruit crop to grow organically, do not need fertilizing or special care.
Hybrid Roses. If you have hybrid roses, cut canes back to just above a strong new shoot when bud growth starts, on strong growing plants. For weaker growers, go easier, just remove diseased wood and pinch back on top.