Spring into the Garden

And now the fun begins.  In King County, we wait impatiently for spring, even though our winters are relatively mild compared to the rest of the country.  The bulbs you planted last fall are blooming, and the flowering plum and cherry trees put on a wonderful show.  Incessant rain may keep us indoors; fortunately there are some outdoor and indoor activities that will get you started.


Get started with garden care by finishing garden clean-up and fertilizing. April is a good time to divide perennial daylilies, iris, chrysanthemum, daisies and phlox.  Hybrid tea roses should be fertilized before their buds open up.  Other flowering shrubs like rhododendron, camellias, and azaleas can be fertilized immediately after they finish blooming, sometime in June.  Check roses periodically for mildew, aphids and other problems and take action immediately to prevent damage.  In May, you can dead-head the spring-blooming bulbs. Leave the foliage until it dies: the plant needs it to generate growth for the next season. By June, you can dead-head annuals and pinch back fuchsias, geraniums, and other annuals that tend to get leggy.  Go after slugs to disrupt their reproductive cycle. There are always weeds to pull.


Resume lawn care in late April by de-thatching your lawn and over-seeding to fill in bare spots and deter moss. Fertilize with a 3-1-2 (nitrogen-phosphorus-potassium) slow release or natural organic fertilizer. Apply moss killers before temperatures reach 65 degrees to ensure they are most effective. Fertilize your lawn again in mid- to late-June. Check your irrigation system to make sure it’s ready for the drier months ahead.  You’ll probably need to mow your lawn once or twice a week and you may even need to water it.


Our latest frost-free date in King County is usually mid-April, so early spring is still a bit early to plant many varieties outdoors. However, you can plant aster, cosmos, marigold, and zinnia seeds directly into beds or gardens.  Vegetables you can plant outdoors include rhubarb, carrots, snow and snap peas, potatoes, radishes, parsnips and onions.  Salad greens are hardier than you might think: plant these outdoors in March and April.


Thin out the dead canes in your raspberry patch and uncover the strawberry beds after all danger of frost is past. Start tomatoes, squash, cucumber, zucchini and pumpkin seeds indoors in peat pots for later transplanting.


In May, put out some containers filled with annuals to add some early color. Get your flower and vegetable starts ready to go into the garden by hardening them off: put them outside during the day and bring them in at night for a couple weeks before transplanting.  Plant corn and beans toward the end of May. By June you can plant the tender ones: tomatoes, peppers, eggplant, basil.


Mix it up in your garden this year. Plant some Swiss chard alongside your annuals for continued color.  Herbs and vegetables go well together also. And just for fun, visit public gardens for inspiration. There are many opportunities in King County.


By Marty Byrne


Click here to Ask Gardening Questions.

Help if you are having trouble signing in. Extension programs and employment are available to all
without discrimination. Evidence of noncompliance may
Website issues? Contact the Webmaster. be reported through your local Extension office.

Copyright © 2021 Master Gardener Foundation of King County, All Rights Reserved. Web Design by FWD»