April 26, 2024: What to plant now, soil amendments

From Linda Gilkeson:

The cold nights over the last month certainly slowed down the arrival of planting weather, but it is time to get onion sets, shallots, onion and leek seedlings into the garden if you haven’t already done so. To grow good-sized onions, they need to be planted as early as possible to have time to develop a good root system before the long days/short nights in June stimulate the plants to make bulbs. If planted too late (after mid-May) onions often don’t make bulbs at all. Which reminds me, if you want to try growing your own onion sets, sow seeds of a good storage variety the first week of May, directly in the garden. Plant densely (3-5 seeds per square inch) and don’t amend the soil with compost or fertilizer before planting because you want to these onions to stay as small as possible. As long as they are sown before mid-May they produce tiny bulbs that will be cured and stored same way as onions for eating. You should be able to harvest over a hundred onion sets from a square foot of soil so it doesn’t take much space to produce enough for next year’s garden.

The soil is warm enough to sow or transplant cool tolerant vegetables (lettuce, spinach, radishes, mustards, kale, peas, Chinese cabbage, potatoes, broccoli, cauliflower, cabbage, carrots, beets), however, for another week or two there is still a risk that climbing cutworms will chomp the seedlings at night. These large caterpillars lurk in the soil during the day and come out at night to eat a variety of tender leaves. When they develop to the pupal stage for metamorphosis into a moth, they look like shiny brown bullets in the soil and are no longer eating plants [for photos see: Linda Gilkeson | West Coast Gardening | West Coast Gardening: Natural Insect, Weed and Disease Control ]. Most cutworms have pupated by the early May depending on how warm it has been so if your earlier seedlings were eaten, just reseed in another week or two. I usually wait until the first week of May, anyway, to sow Swiss chard because it is readily vernalized by cool weather (see my message about vernalization Feb. 20, 2022: Linda Gilkeson || West Coast Gardening || Gardening Tips). Late planting eliminates the risk that plants could flower prematurely this summer.

As for when to put out the tomatoes and squash, when the night temperatures in your garden are over 10oC [50oF] most nights, plants will be fine, even if there is an occasional cooler night or two. Cucumbers, melons and sweet basil, however, are really sensitive to cool weather and will fare better if planted out after the weather has warmed up even more. In some years I have had to wait until the end of May to plant them out. If you do plant earlier, watch the weather forecast and be ready to cover plants with cloches or floating row cover on cool nights.

In recent years, we have also experienced the opposite problem: heat waves in early May with temperatures reaching 30-32oC (86-90oF), high enough to kill seedlings. With the variable weather now a frequent consideration, be prepared to sow more seeds if a late frost, an early heat wave or pounding rainstorm damages seed beds or seedlings (or if slugs, cutworms or birds ravage the plantings). If worst comes to worst, there is plenty of time in our growing season to start over with most vegetables from seed or from starts. Many spring vegetables (lettuce, peas, radishes, cauliflower) are best sown in a succession of small amounts every 2-4 weeks, anyway, because they don’t keep for long in the garden once they are ready to pick. Plants that need all season to develop fruit (winter squash, pumpkins, melons, corn) and veggies that continue to produce all season from the same plants (e.g., tomatoes, peppers, Swiss chard, kale) are not usually planted in succession.

Pest tip of the month: Wireworm adults (click beetles) are laying eggs this month. A long-time reader of this newsletter, Domena D., discovered that in early spring, adult click beetles would hide during the day under boards or shingles laid around the edges of her garden beds, making it easy to collect and kill them in the morning. I tried this and was surprised how many could be found. These beetles are still laying eggs so you might want to deploy some boards to intercept what you can before they even lay more eggs. For what click beetles look like, see: Linda Gilkeson | West Coast Gardening | West Coast Gardening: Natural Insect, Weed and Disease Control. Info on using potato traps for the larvae (wireworms) was in last month’s message, March 28, 2024.

Local organic veggie starts:

Local sources of organic vegetable starts, usually with a wider range of varieties than found in garden centres, include:

-Salt Spring: Chorus Frog Farm, 190 Jasper Rd. has organic vegetable and flowers seedlings. Especially of interest for this summer is ‘Purple Moon’, a heat-tolerant purple cauliflower. Later in the season they will also have starts of many overwintering veggies. Chorus Frog Nursery | The Quarry Farm

-Victoria: Compost Education Centre is holding a one-day organic plant sale, May 11, 10:00am-2:00pm in Haegert Park (1202 Yukon St). At least 8 growers will have plants for sale. https://compost.bc.ca/

ABCs of Gardening Enriching the Soil, Part 3: Compost and Fertilizer

This section contains notes especially for beginning gardeners. The series started with my December 21, 2023 message: Linda Gilkeson || West Coast Gardening || Gardening Tips

Vegetables need fertile soil that provides a lot more available nutrients than landscape plants or native plants would need. To produce such large crops—think how big a head of cabbage or a full crop of tomatoes grows in just a few months—vegetables must take up a lot of nutrients. For an organic garden, the two main ingredients for improving the fertility of the soil are compost and organic fertilizers.

“Compost” ranges from leaves or garden waste left in a bin until decomposed to commercially composted products from municipal or fish/wood waste. Well-rotted manure is also a kind of compost. Compost adds organic matter to the soil, which soil microbes digest, releasing nutrients for plants to take up. All compost is useful as a soil amendment, but the amount of major nutrients (nitrogen, phosphorus and potassium) in compost depends on the starting ingredients, how the compost was made and how it has been handled. If compost is left uncovered through winter rains, for example, the valuable nitrogen and other soluble nutrients leach away and are lost. Commercial fish/wood waste composts and municipal composts are generally higher in nutrients than homemade composts. The amount to use depends both on the quality of the compost and how many years the soil has been enriched—as well as what is practical for a gardener to buy or haul.

For the first few years of a new garden, apply a layer of leaf compost or homemade compost a couple of inches deep over the bed, if possible. If using a higher quality commercial compost, you only need to apply it an inch or so deep. After the first few years of generous additions to build up soil organic matter you can dial back on the compost, especially if you are keeping the soil well mulched. Organic mulches, such as leaves or straw, also increase soil organic matter as they decompose.

When buying bagged compost, read the contents listed on the bag to ensure you are getting only compost rather than a soil and peat mix with compost in it. For example, “Original SeaSoil” is the brand name of a good quality fish/wood waste compost. It is sold by the bag, but is also used in organic planting soil mixes. There are other planting mixes with confusing names (such as Ocean Forest, Organic Fish Soil, Ocean plus Earth) that sound like they might contain only fish compost. Some compost products are organic, others are not: If it is approved for organic growers, it will say it is listed by the Organic Materials Research Institute (OMRI) on the bag.

Upcoming talk open to the public:

Saturday, May 4, Managing Pests & Diseases in your Organic Vegetable Garden (presented via Zoom online for the Compost Education Centre). I will cover how to identify problems and when to use the organic and non-toxic control methods available to home gardeners. The emphasis will be on ways to prevent damage from common pests and diseases, including how to attract beneficial insects that control aphids, caterpillars and other insects. To register, follow the link beside the workshop title: 2024 Public Workshops – Compost Education Centre

Book sale:

The publisher of my book, Backyard Bounty, is having a spring sale: Until April 29, all books are 40% off and there is free shipping on orders over $70. Discount code: Spring40 https://newsociety.com

Republished with permission from Linda Gilkeson’s Gardening Tips. See Linda’s website to sign up for her newsletter, purchase books, access free presentations and identify pests and diseases which may affect West Coast gardens.

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