Cool Season Crops

EARLY FAVORITES

Arugula, beets, bok choy, broccoli, carrots, fava beans, kohlrabi, onions, parsnips, peas, shallots, and spinach

by Anza Muenchow

During March, the day length increases quite dramatically, and plants really respond to the extra light. The temperatures are creeping up, but not as dramatically as the light change. Take a walk and notice our native trees and shrubs. They are going crazy with the added light.

I like to divide our typical garden crops in two categories: cool season and warm season. More on warm season will be discussed later this year.

For the cool season, the earliest crops we plant are peas and fava beans. Also plan to plant your onions and shallots. Onions are a special crop because they are day length sensitive and need to put in most of their growth before the days start to get shorter, which happens at the summer solstice on June 20th. Onion seeds don’t sprout in cold weather. Gardeners can plant them in the fall or start them indoors in February. There are often bundles of onion starts for sale at nurseries or farm stores. Select some sweet onions and storage types and plant them outside in mid-March.

Additional cool season crops that local gardeners enjoy are arugula, spinach, kohlrabi, carrots, parsnips, beets, bok choy and broccoli. You can start sowing these in mid-March through April. I usually plant spinach when the wild dandelions are blooming, so probably early April. All these crops like to be covered with floating row cover, which warms the soil slightly and inhibits many local pests.

Consider planting your crops in raised beds, by either mounding the beds or building a frame to fill with soil. Raised beds allow the soil to warm sooner and drain better, which generally allows you to plant one or two weeks sooner than conventional flat beds. Put the beds in a sunny spot, with good southern exposure.

What about soil preparation? Spring is a good time to mix lots of rich compost into your planting beds. Try incorporating as much as 6 inches of compost with your topsoil. If you have worm casting compost or a well-decomposed leaf mold compost, this may be enough soil fertility for most of your summer fruiting crops, such as tomatoes, beans, peppers and squash. For greens (for example lettuce, broccoli, spinach, chard and mustards), you may want to add an additional organic nitrogen source like composted manure, fish fertilizer, alfalfa or bone meal. These are usually sold in packages that have three numbers on the front. Pick an organic fertilizer with the first number (the percentage of nitrogen) being the largest number of the three. I encourage using an organic product because it releases the nitrogen slowly, which nourishes the microorganisms that make for healthy soil.

Since much of our rain-soaked soil is acidic, you may want to add lime to “sweeten” your soil before you plant, especially if you haven’t added it in the last three years. You can purchase an inexpensive bag of garden lime in most nurseries. The brassicas (broccoli, kale, cabbage, bok choy) especially like limed soils. But strawberries, most other berries and potatoes do not like the soil to be limed.