Pacific Northwest Gardening in April
Average last frost March 22, Safe Date April 15
- Keep on with general clean-up and pruning back dead wood and old perennials.
- Start some serious weeding before things get out of control, mulch to reduce weed germination.
- Prepare garden beds by adding organic material such as compost or manure.
- Cut back ornamental grasses to a few inches before new growth begins.
- Start the slug patrol, remove hiding places, hand pick or use iron phosphate bait.
- Be on aphid alert! Wash them away with a stream of water or use insecticidal soap.
- Fertilize perennials, roses and flowering shrubs with a good organic fertilizer (if not done in March).
- If needed, aerate, thatch and re-seed lawn.
- Complete spring pruning on roses and shrubs like hydrangeas. Shape and thin after blooms fade for rhododendrons, forsythia and lilac. Remove dead wood first!
- Prune pines to reduce size by cutting ‘candles’ (emerging shoots).
- Consider using a fungicide such as copper soap on roses, dogwood trees and other plants prone to fungal diseases.
- Visit a local plant sale, like LWIT Horticulture in Kirkland, WA April 25-26, 2014
- Enjoy the rainbows and the rain. Celebrate Earth Day April 22 and plant a tree!
- Sow hardy annuals like sweet alyssum, cosmos, cleome, marigolds, California poppies and sunflowers, plant pansies
- Summer bulbs like lilies and gladiolus and dahlia tubers. Visit the Seattle Dahlia Society website for tips on planting and growing.
- Cool season veggie crops like lettuce, peas, cabbage, onions, spinach, radish, etc… (think leaves and roots)
- Container roses.
- Herbaceous perennials
- This is the best time to plant trees and shrubs, before summer heat.
Consider adding flowers and herbs to the veggie garden to attract beneficial insects: Angelica, fennel, dill, yarrow, catnip, rue, thyme and alyssum.
- Cercis canadensis
- Magnolia x soulangeana
- Magnolia stellata
- Malus (Crabapple)
- Osmanthus delavayi
- Ribes sanguineum
- Basket of Gold
- Bleeding Heart