A few chores to get a jump-start on gardening season
If late winter was an indicator, we are headed for a bumper crop of flowers this spring. I saw the first color in Chevy Chase on the forsythia March 8 with buds opening enough to tease with a hint of yellow.
On March 6 the temperature was in the mid-40s and it seemed like every winter-flowering jasmine I saw was heavy with more blooms than I've ever seen. The same seemed true for vernal and Chinese witch-hazels. The Oriental hellebores caused me to lift their lower leaves to discover buds and flowers. Be on the lookout for snowdrops (Galanthus) with beautiful drifts of white bell-shaped flowers, scilla, winter aconite, rosemary (in a protected location), violets and pansies.
This parade of flowering plants will continue because spring officially begins tomorrow. Here are some suggestions for appropriate spring gardening tasks:
Pull weeds at the first sign of undesirable growth. There are many winter weeds that capitalize on the care you provide for your ornamental plants during the rest of the growing season. These weeds go to flower and drop seed. As you grow your vegetables and flowers from seedlings, arrange them in clearly identifiable rows or mounds. As the weeds begin to grow, they should be obvious because of their random arrangement and pulled. Watch for them; learn their growth habits. Spot-treat with as harmless an herbicide as possible.
Some easy-to-pull weeds that can be controlled if pulled while they're young are mustard, sour grass, henbit, ground ivy, English ivy, amur honeysuckle, wild violet and crabgrass.
Weeds that germinated in fall and winter, including chickweed, speedwell, henbit, peppergrass, shepherd's purse and yellow rocket, can be pulled by hand or by using a weeding prong. Most will come out easily in moist spring soil. It's the surest way to keep them from going to seed. Spread pre-emergent weed killer to control spring weeds such as crabgrass or control with corn-gluten-based material available at your local garden center. They are safe as long as you follow all labeled instructions.
Planting and transplanting
Move perennials, shrubs and trees in late winter as soon as the soil is friable and moist and daily high temperatures reach an average of 50 degrees Fahrenheit. They should have a tight root ball. Install plants only if tender young leaf buds have not yet emerged from their dormancy or if healthy trees and shrubs were dug by the nursery before bud break in spring. Install pre-dug plants in late winter before the plant breaks dormancy, and make sure to prepare your garden with a one-to-one mix of compost and native soil.
It is too early to plant frost-sensitive plants. Most frost-sensitive annuals that are expected to flower all summer should not be planted until May 1. Some freeze-tolerant plants that you can grow in March and April are pansies, snapdragons, kale, lettuce, spinach, arugula, beans, broccoli, cauliflower and cabbage.
Except for renewal pruning, most tree and shrub pruning is done later in the season. Candidates for pruning now are woody plants that are still dormant and overgrown plants that need to be cut hard before growth begins.
Early flowering shrubs such as forsythia can be treated as perennials and cut back hard after flowering. Prune them once a season and let them grow back into full, natural shrubs. If the wood is starting to get dense, flowering quince can be cut back hard after flowering. Azaleas can be pruned if needed as their flowers fade. Cut no more than one-third of the volume of the plant. Lilacs are another plant that responds well to pruning after flowering. Cut woody stems with furrowed bark to the ground to avoid lilac borer. New shrubs will return from the old wood that was cut hard.