Pacific Northwest Gardener: What to Do in April

Condition Your Soil

Many garden favorites, including lilac, mock orange, slender deutzia and daphne, prefer alkaline soil to best soak up the its nutrients. But most of the Pacific Northwest tends to have more acidic soil, so these garden plants need a little help to perform well. Sprinkle garden lime in a circle around the base of each lime-loving plant (follow the package directions as to how much) to make sure the pH in your garden stays alkaline enough for these beauties.

Lawns also prefer alkaline soil, and likewise, April is the perfect time to adjust the pH with a fast-acting garden lime such as Lilly Miller Super Sweet. Because lawns tend to have a lot of square footage, it’s easiest to use a walk-behind broadcast spreader to apply. Broadcast spreaders are inexpensive to buy, and many nurseries have them available to rent for a very small fee.

Hydrangeas are another type of plant that may benefit from liming. While hydrangeas are perfectly happy growing in either acid or alkaline soil, the color of many mophead hydrangeas changes depending on the pH of the soil. Varieties like ‘Endless Summer’ turn pink when treated with lime and blue when given an acidic fertilizer like cottonseed meal.

Plant Cool-Season Vegetables

April is the perfect time to set out starts of cold-tolerant vegetables. While it’s not yet time to set out starts of heat-loving plants like tomatoes, squash, corn or peppers, by planting less-sensitive veggies now you can get a great jump on the season.

Vegetables to plant now include cabbage, broccoli, cauliflower, Chinese vegetables such as pak choi, Swiss chard (the 'Bright Lights' variety is shown), carrots, beets, celery, lettuce, onions and herbs such as parsley, chervil and cilantro (hold off on basil for now). Onion sets are available at nurseries now, and these already-sprouted starts take off quickly in the damp, cool weather.

Photo via Renee's Garden

Plant Flowers

Annual flowers to plant in April include snapdragons, sweet William or annual dianthus, nasturtium, calendula (shown), marigold, pansy, dusty miller and sweet alyssum.

Sweet alyssum and calendula are great choices of annual flowers to incorporate into vegetable garden areas, because the flowers attract pollinators that will help you get a good crop. Renee’s Garden has some lovely, unusual varieties of these seeds, like ‘Summer Peaches’ sweet alyssum (shown) and the vivid ‘Flashback’ calendula.

Photo via Renee's Garden

Control Snails

You'll want to protect your new starts and seedlings from the ravages of snails and slugs. It’s also smart to protect the shoots of emerging perennials, which are susceptible to damage. Dahlias, hostas (shown), bear’s breech, lilies and Canterbury bells can all benefit from spring applications of organic snail bait.

I use pet-safe iron phosphate bait around growing seedlings. Brands such as Sluggo are widely available at hardware stores and nurseries, and they’re easy to apply. Simply sprinkle a small amount of bait around new plants. Just don’t set it into piles, which can mold or be easily eaten by pets or kids. By sprinkling, you make it less likely that anyone would consume the quantities necessary to cause iron poisoning.

Photo by benketaro on Flickr via Creative Commons