This is the time when days grow longer and warmer, so it is a busy month in the garden for both plants and gardeners alike. April is also traditionally a month when showers can be expected, however, be prepared for dry and windy spells and water plants where necessary.
Here’s your April gardening guide for North America’s USDA Plant Hardiness Zones: 3-10. If you don’t know what zone you live in, check the map here to find out. We’ve left off zones 1–2 (far-north Alaska) and zones 11–13 (small section of the Florida Keys, the Pacific coast between L.A. and Mexico, and Hawaii) since zones 3–10 cover 99 percent or more of the gardeners in the U.S.
- Dig up and enjoy parsnips still left in the garden from last fall.
- Dig compost into beds as soon as the soil can be worked.
- Fertilize established lawns.
- If weather allows, plant onion sets, lettuce, spinach, peas, sweet peas (Lathyrus odoratus), carrots, and parsnips in the garden.
- Indoors, continue to start seeds of squash, melons, and corn.
- Start gladiolus corms indoors.
- Sprout seed potatoes by moving them from cold storage into room temperature.
- In the last week of the month, remove winter covering from tender roses, perennials, and strawberries.
- When the soil has warmed and dried, plant cold-tolerant crops, such as peas, spinach, lettuce, radishes, and onion.
- In flowerbeds, plant lilies, primroses, and lilies-of-the-valley.
- Plant raspberries as soon as possible, but wait until the soil has begun to warm before planting strawberries.
- Dig and divide perennials, such as daylilies and irises.
- Indoors, start tomato seeds if you plan to set them out under protective covering next month.
- If you’re planning To Grow Broccoli start seeds indoors for an early crop—but don’t delay; soon it will be too warm.
- If the ground has thawed, divide and replant perennials, such as asters, bee balm, and hostas.
- Plant roses and lily bulbs.
- When the ground is warm and dry, transplant early tomatoes outdoors, inside protective Wallo’Waters.
- Seed a second crop of lettuce (start the seeds indoors or sow them directly in the garden).
- Sow spinach in the garden to get tender leaves before the weather warms.
- Clean up the garden in preparation for the season ahead: Remove last year’s dead plants, rake back winter mulches, and top-dress beds with compost.
- After you’ve finished preparing your beds, plant potatoes, peas, spinach, and other leafy greens as well as beets, turnips, and carrots.
- Put up a trellis for tall varieties of peas as soon as they sprout.
- Dig, divide, and replant perennials, such as helenium, fall asters, Shasta daisies, chrysanthemums, and phlox.
- As soon as the weather settles, plant transplants of pansies, forget-me-nots (Myosotis spp.), foxglove (Digitalis spp.), and other cool-weather flowers.
- Sow seeds of sweet peas, bachelor’s buttons (Centaurea cyanus), and larkspur (Consolida ajacis) in flowerbeds.
- Pass by broccoli and cabbage on sale at garden centers—hot weather will soon arrive, causing plants to go to seed instead of forming edible heads.
- Thin crowded carrots, chard, and lettuce.
- Remove floating row covers from peas early in the month. Drive tall, twiggy branches into the ground next to the plants for support.
- Mulch around the base of cool-season crops to keep their roots cool and moist.
- Select new azalea and rhododendron bushes while they’re in bloom to make sure that the color complements your landscape.
- Give flowers and vegetables a foliar feeding of liquid seaweed or compost tea; spray the liquid nutrients on foliage early in the day before it gets too hot.
- Plant black-eyed, purple hull and crowder peas, okra, peanut plant, sweet potatoes, squash, melons, cucumbers, and corn—all can withstand the heat that will arrive in less than 2 months.
- Keep planting basil—it loves the warm weather.
- Plant “bulbs” of caladium, calla, gladiolus, and water lily.
- Keep adding kitchen scraps and grass clippings to your compost pile.
- Replenish your mulch!
- If slugs and snails are decimating your plants, collect them in the evening, when you’re most likely to spot them.
- Plant pumpkins, summer squash, melons, and other vegetables that thrive in heat.
- Every 2 weeks from now until late summer, plant small blocks of bush beans and sweet corn to extend the harvest until frost.
- Thin fruits on fruit trees to increase their size and keep branches from breaking.
- Plant summer bedding plants, such as petunias, lisianthus (Eustoma grandiflorum), wax begonias, and impatiens.
- Sow seeds of nasturtiums, marigolds, portulaca, amaranthus, salvias, vinca (Catharanthus roseus), sunflowers, and zinnias.
- Plant perennials like ornamental alliums, bellflowers (Campanula spp.), daisies, yarrow, daylilies, coreopsis, penstemon, perennial geraniums (Geranium spp.), iris, and statice.
- Plant perennials so they can settle in before the summer heat arrives; give them plenty of water.
- Plant heat-loving bedding plants, such as vinca (Catharanthus roseus), strawflowers (Helichrysum bracteatum), blanket flowers (Gaillardia spp.), and gazanias.
- Plant roselle (Hibiscus sabdariffa), amaranth, and Malabar spinach (Basella alba) now through August; make sure you give the Malabar spinach some shade and extra water.
- Try some tropical edibles: Buy malanga, gingerroot, and others at the market. Cut them into pieces at least 1⁄2 inch long, and plant. Harvest from October through December.
- Trellis tropical cucurbits (luffa, chayote, Tahitian squash, and so on) on a fence, and reap the rewards this fall.