Early April
It’s time to . . .
- Hand pull or spot treat emerging weeds.
- Plant asparagus crowns (roots) in trenches about six inches deep, and gradually fill in with soil as the plants grow. CSU Fact sheet 7.615
- Work nitrogen fertilizer into established asparagus bed before the spears emerge.
- Start tomato seeds indoors.
- Plant dill outdoors, pressing lightly into the soil. Soak parsley seeds for about 24 hours, then plant them outdoors one-fourth inch deep.
- Core aerate the lawn.
- Remove protective coverings from the trunks of young trees.
- Plant container or "balled and burlapped" trees and shrubs now or later in the spring. CSU Fact sheets 2.926, 7.417, 7.226
- Start indoors asters, dahlia, and other annual seeds that take six weeks to grow to transplant size.
- Water perennial beds and bulbs if the weather is dry.
- Plant bare root roses.
Mid-April
It's time to . . .
- Plant these seeds outdoors now, if the soil is not too wet: lettuce, chard, spinach, kale; beets, carrots, radishes, turnips; onion sets. It’s not too late for peas.
- Water lawn one inch a week if weather is warm and dry.
- Check mower blades for sharpness. Set them at 2-1/2 to 3 inches, and maintain this height throughout the year.
- Use pre-emergent herbicide if sodding (not seeding) a new lawn or if weeds were a major problem last year. Read the labels and choose carefully! Then use according to label directions.
- Watch for new growth on roses. Once it starts, prune back dead or damaged canes. Begin removing mulch, about 1/3 at a time, at 10 day intervals.
- Transplant or divide summer-and fall-blooming perennials when the soil has thawed but plants are still dormant.
- Begin planting new perennials. "Harden-off" outside for a few days if bought from an indoor nursery.
- Start seeds indoors of flowers such as zinnia and celosia that need four weeks before planting outside.
Late April
It’s time to . . .
- Begin thinning vegetable seedlings to recommended spacings.
- Fertilize lawn only if spring green-up and growth are unsatisfactory. Use a slow-release chemical fertilizer (e.g. forms of urea), one-half pound per 1,000 square feet.
- Reseed bare spots in the lawn.
- Start quick-growing annual and herb seeds indoors: basil, cosmos, marigold, statice.
- Sow alyssum, bachelor button, and dianthus seeds outdoors.
- Start shopping for annual plants at garden centers.
Home Grown Transplants Require TLC
Spring Tree Planting . . . Do It Right
Not All Grass Seed is Created Equal
