Sowing cole crops, planning your vegetable garden rotation, and pruning woody plants are some of the gardening activities to plan for the month of March.
Start seeds of cole crops, including broccoli, cabbage, Brussels sprouts, and cauliflower indoors under lights. You'll have transplant-sized plants in about 6 weeks, ready for planting outdoors a few weeks before the average last spring frost date.
To get a jump on the herb gardening season, start seeds of basil, parsley, sage, and thyme indoors. Start seeds in flats filled with moistened seed-starting mix. Once the seeds germinate, place the plants under grow lights for 14 hours a day (timers make this easy) and keep soil moist.
As you begin planning and planting your vegetable garden beds, remember to rotate crops: Avoid planting crops in the same family in the same spot more than once every three years. Tomatoes, peppers, and eggplant are in the same family; so are squash, cucumbers, and pumpkins. Many pests and diseases overwinter in the soil, so moving plants around can disrupt their life cycles and minimize your need for pest and disease controls.
Most trees and shrubs are best pruned in late winter, after the coldest weather has passed. The exceptions are spring-flowering shrubs, such as forsythia, lilacs and azaleas, which should be pruned immediately after flowering. You can remove dead or damaged branches at any time.
Cut branches of forsythia, quince, pussy willow, and other early-flowering shrubs for forcing into early bloom. Bring the branches indoors and place in a vase of water. They should bloom in a few weeks. Once pussy willows reach their peak, remove them from the water and allow them to dry; they'll continue to look great in dried arrangements.
Plant begonia tubers in containers to get an early start. Plant them hollow-side-up in well-drained potting soil. Set them in a warm (70 degrees F) location and keep the soil moist but not soggy. Once you see growth, usually in 3 or 4 weeks, place the pots in bright, indirect light. Wait to plant outdoors until all danger of frost is past.
Although April is the month to sow seeds of many flowers, some take longer to mature and so should be sown this month. Flowers you may sow early in March include dusty miller, geranium, heliotrope, impatiens, osteospermum, petunia, mealycup sage, torenia, verbena, and annual vinca. Flowers you may sow the middle to end of March include ageratum, coleus, dianthus, ornamental millet, African marigold, ornamental pepper, annual phlox, rudbeckia, scarlet sage, and thunbergia.
Keep in mind that seed catalogs and packets often give "days to germination" which is the time for seeds to sprout, not the time until they are ready to plant outside. You can find these times for the above plants, and more, online (perrysperennials.info/consumer.html) in the Vermont Extension leaflets on Indoor Seed Sowing for Flowers (OH89) and Vegetables (OH90).
Other gardening activities for this month include watching for and attending flower and garden shows, visiting a maple sugarhouse, and removing heavy winter mulch from perennials.