VIU Milner Gardens and Woodland

April Garden Tasks

What should I do in my garden in April? 

by Vancouver Island Master Gardeners Association

It is a month to plant the first seedlings, dig those weeds and pick moss from the lawn to line the hanging baskets. The frost date is mid-month, the glories of spring abound, and so do some of our allergies. Oh, and sun screen – get into the habit early this year.

First, Be Patient

The ground is often colder in April than November. Seeds planted too soon can rot and young plants may damp-off or remain stunted throughout the season. Harden off first, bringing plants in at night, or covering them with frost blankets until the soil is above 55 F at night. In the meantime get all your compost and amendments and green manures dug in early so the cold spring soil time to break down new nutrients.

Before Frost Date:

● Indoor flower starts: half-hardy annuals, sweet peas

● Pot up tomatoes, peppers, and squash

● Harden off over-wintered tender perennials, lettuces, mustard and salad greens.

● Direct seed the last of the green peas, corn salad, spinach, endive, carrots, kohlrabi, fennel, leeks, scallions.

● Direct seed flowers & herbs: borage, chives, columbine, perennial herbs, spring-planted bulbs.

● Prune berry canes when growth looks strong

● Divide ornamental grasses and autumn-blooming perennials

Who’s Hungry?

Feature shrubs in planters are putting on growth. Before adding the seasonal mulch, lift them to check root health. Loosen the soil that may have become compacted over winter, add a few worms from your compost bins, and slide down a bit of compost around the outside of the planters. All set!

Scratch in nitrogen-rich fertilizer (like flax meal) around over-wintered leeks, onions, and garlic. In addition to a growth boost, the nitrogen stops premature flowering because alliums can bolt after only a few days of early warmth even if it gets inclement again. A shot of liquid fertilizer (like fish emulsion) is an idea as this gives the slower amendments time to activate in cold soil. Berry canes also benefit from this treatment.

Soon We’ll Be Frost Free

● Indoor Veggie starts: harden off celery, cucumbers, eggplant, peppers, melons, pumpkins, and squash so they will be ready to transplant once the soil is above 60 F.

● Outdoor veggies: direct seed carrots, spinach, endive, scallions, turnips, beets, Swiss chard, potatoes.

● Flowers: paeonies, tender summer bulbs, and the rest of the annuals, like sunflowers.

Watch the Weather

Keep row cover over your tender plants. They warm the soil faster, keep out hungry birds, & foil the neighbour's cat who may dig up newly-tilled soil as a WC.

Pest Patrol

Potato slices catch wireworms around the edges of the veggie patch. Protect carrots with row cover against rust worm. If you put it down before they come up, you’re ahead of the game. It also helps keep the soil moist over the tiny, shallowly-planted seed. Check fruit and ornamental trees for tent worm.

I Forgot!

There is still time to clean bird nesting boxes. Some songbirds have already nested, but some have lost their first nests and will start a second one. You’re right on time for tree swallow boxes.

And Finally,

The Symplocarpus (skunk cabbage), Erythonium (forest lily), Trillium (wake robin) and Dicentra (bleeding heart) and are blooming in the forest. Time to pause the work, and wander with the eyes of a child.