There are some great plant sales coming up in the next few weeks. We want to call your attention to two sales in Seattle in early May.

As Master Gardeners, both Andy and I will be volunteering to help the Master Gardener Foundation of King County with its annual plant sale. There’s a huge selection of annuals, perennials, vegetables, trees and more. Many are grown by local master gardeners, while some professional nurseries will also be on hand to sell their goods. Proceeds go toward paying for the Master Gardener clinics, demonstration gardens, youth programs and more. The Master Gardener Plant Sale is May 2-3, 2009 at the University of Washington Center for Urban Horticulture, 3501 NE 41st St, Seattle. Hours are Saturday, 8 a.m.-5 p.m.; Sunday, 10 a.m.-3 p.m.

If you’re into growing vegetables, head to the Seattle Tilth Edible Plant Sale that same weekend. I’ll be volunteering to help out with this sale, which offers the largest selection of organically and sustainably grown vegetable starts in Seattle. You’ll find over 50 varieties of tomatoes and 20 varieties of peppers, rare and heirloom veggie varieties, an extensive selection of culinary herbs, edible flowers, and drought tolerant perennials. The list of starts includes ‘Fairy Tale’ eggplant, lemon cucumbers, golden midget watermelon, ‘Cajun Delight’ okra, ‘Gypsy’ sweet peppers and much more. Find the lists of items on sale here. The sale is May 2-3, 2009 at Meridian Park in Seattle’s Wallingford neighborhood, 4649 Sunnyside Ave. N. Open 9 a.m.-3 p.m. Saturday & Sunday.

If you need help finding the right plant to fit into your Seattle landscape, Ecoyards is here to help. We love assisting clients to find the right perennials, trees, even edible plants, to incorporate into an existing landscape or add to a newly-designed landscape. Email us or give us a call at 206-770-7879.

You wouldn’t know it’s April, given the snow and cold weather we’ve been having lately. Despite that, daffodils and forsythia are strutting their stuff, tulips are poking through the cold ground, cherry blossoms are in full bloom, and we just noticed some blooming trillium deep in the woods of Schmitz Park in West Seattle.

Now is a good time to walk around your yard and give your landscape a good once-over: What plants are going well and where? What plants should be moved so they thrive better? Could you add a paver patio or walkway to your landscape to make it easier for people to move through it, or add interest to your landscape?

Here’s what else you can do in the garden this month:

1. Finish cleaning your garden by pulling weeds while they’re still young.

2. Plant annual seeds of asters, cosmos, marigolds, zinnias.

3. Plant cool season crops such as peas, lettuce, radish, and broccoli through seeds or transplants.

4. Fertilize raspberries with ammonium sulfate to lower the soil pH, just as bud swell begins. Apply about 3/4 to 1 pound of ammonium sulfate per 100 feet of row. Give blueberries a spring application of a balanced fertilizer such as 5-10-10.

5. April is Arbor Month so it’s a good time to plant trees. The second Wednesday of the month, or April 8 this year, is the official Arbor Day in Washington state.

6. Plant strawberries, which you should be able to find bare-rooted in most nurseries this time of year. Give strawberries a sunny spot and good drainage and they’ll produce for you for three to five years. Weed the bed, work in a good amount of compost or manure and about 4 pounds of 5-10-10 fertilizer per 100 square feet.

7. Shear winter flowering heather after it blooms.

8. Prune forsythia once it is done flowering.

The weekend brought a fair amount of snow to the lowland areas of the Puget Sound, but there was still enough breaks of sunshine and warmth to think about starting your vegetable garden.

This is a great time to plant some cool season crops, or vegetable plants that are best suited for cooler temperatures, an average of 50 to 65 degree F. Cool season crops include beets, lettuce, collards, radish, peas, leeks and spinach and others. They’re grown in the spring or fall, and often don’t thrive during the warmer summer months (they’ll bolt, which means they’ll go to flower, leaving you with a bitter crop).

By contrast, warm season crops shouldn’t be planted until later because those crops require warmer temperatures to thrive. These crops includes tomatoes, potatoes, cucumbers, squash and corn. In the Puget Sound, warm season crops generally shouldn’t be planted until mid-May. If planted too early in soil that is cold and damp, these seeds won’t grow well and may not set fruit for a long while.

I recommend growing vegetables in raised beds, wherever possible. Your bed could be as simple as a large mounded pile of soil, or as fancy as one made from cedar boards or, as pictured to the left, made from RomanStack blocks. Raised beds help drain water better and warms the soil up quicker so that you can extend your planting season. It helps keep weeds out of the bed, and prevents your soil from becoming too compacted from excess foot traffic. Ecoyards has made several lovely raised beds for clients, including the one pictured at left.

The soil in my cedar raised beds is much warmer than elsewhere in my landscape, so I went out this afternoon, added organic matter to the beds (compost and a little alfalfa meal) and dug it into the soil. I was ready to plant. I planted peas (‘Cascadia’ and ‘Sugar Snap’) spinach (‘Olympia),  radishes and a gourmet blend of lettuce from seed. I also transplanted some collards and broccoli that I picked up at Swanson’s Nursery.

Here are some cool-season crops that you can start outdoors from seed: radish, swiss chard, beets, mustard greens, onions, parsnips and spinach. Here are the cool-season crops that do best when started indoors and transplanted (or you can pick up vegetable starts at a local nursery): cauliflower, broccoli, brussels sprouts and celery.

Western Washington University Extension has some great resources for all aspects of gardening.

There’s an old saying in the Northwest that says you should  plant peas by President’s Day. But if you haven’t gotten around to it, March is a great time to do it. (April is fine, too, but by then try to plant virus-resistant varieties. Peas grown in warmer weather are susceptible to pea enation, a virus transmitted by aphids that appear once the weather warms up).

Peas are a cool season crop that, for me, signals the start of the active vegetable gardening season. They thrive in the Northwest — provided they get sun and are planted in well-drained soil.

Sugar snap peas are a given in my garden. I like “Cascadia” snap peas, an enation-resistant variety developed at Oregon State University.  (Read more here). The peas grow on short vines and produce thick, juicy, sweet pods. “Sugar Snap” is another favorite variety of mine, but since they grow 6 feet tall, they need a strong trellis system. The pods are especially sweet and taste great plucked right off the vine. (Territorial Seed Co. in sells both varieties, and their packets can be found at most Northwest nurseries.

Read more about growing your own peas and beans here.