Waking the Garden Up
Earth Day is this weekend, which is a typical planting date for cool-weather crops in Chicagoland. Cool-weather crops such as broccoli, kale, and parsley can handle slight dips in nighttime temperatures, provided they have been hardened off properly. This is also a great time to plant radish, carrot, and spinach seeds directly in the garden. Be careful not to transplant warm-weather crops such as basil and tomatoes yet. These plants may be damaged by nighttime lows below 55 and are better off planting around mid-May, unless going into a cold frame or plastic-covered high or low tunnel.
Earth Day is also the the time to get the garden ready to wake up. This month you’ll want to:
-Inspect your garden for returning perennials such as strawberries, thyme, mint, oregano, sage, tarragon, chives, and lavender. Keep in mind some perennial herbs may not fully leaf out until mid-late May, so don’t assume they are dead just yet.
-Begin hardening off your overwintered rosemary
-Pull weeds, inside and outside of the bed
-Remove heavy mulch around your fall-planted garlic plants – only a light mulch is needed at this time
-Examine your plot for self-seeded plants such as dill, lettuce, and borage. Bonus!
-Condition, prep, and protect your soil
How to condition your soil:
If you didn’t add compost last fall, do it now. This is the time to remove worm castings from your indoor bin, finished compost from your outdoor bin, or purchase a quality compost. Compost adds essential carbon to the soil (organic matter) for beneficial soil microbes and fungi to digest, as well as bind to soil particles to increase nutrient and water retention. If you want to improve the quality of your soil, compost is the way to go. For a 4’x8′ bed, you’ll want to add anywhere from 1-5 cubic feet of compost.
To start, add 1-4″ of compost to the top layer of soil, then scratch in with a garden rake or action hoe to incorporate into top few inches of the bed (don’t turn the soil – just scratch it in). Leaving the compost on the surface without incorporating into the soil can be counter productive – it may dry hard and form a barrier that is difficult for rain to penetrate. Avoid any urges to turn, double dig, or till your soil. While commercial famers may plow their fields in the spring, it is not necessary and can be counter-productive in a raised bed. It is important to retain the soil structure, and only cultivate the top few inches to incorporate compost and prepare an area for direct-seeding.
If a soil test has indicated that you are low on a specific nutrient, add soil amendments such as bone meal, blood meal, or potassium. These amendments are usually much more concentrated than fertilizers, so it is important to follow the application instructions exactly. Be sure to get a soil test before adding any amendments – too much and you may burn your plants or alter your soil’s pH, making nutrient uptake difficult.
If you haven’t done a soil test or aren’t planning to, you can add a little all-purpose organic fertilizer to each planting hole. Usually 1 tsp.-1 Tbs. is sufficient to provide your plants with balanced nutrition for several weeks while they grow in an intensively-gardened plot. You’ll want to add a little more fertilizer again in July as a side-dressing, particularly for heavy-feeding plants such as tomatoes, brussels sprouts, and kale.
How to protect your soil:
If you’ve noticed your soil appears gray, rocky, and hard, it may have not been fully protected from the harsh winter weather. This doesn’t mean your soil is ruined – within a few weeks of conditioning and covering you will notice obvious improvement. To protect from erosion and improve the soil structure, cover any bare, unplanted surface with plant material such as tree leaves, straw, or burlap. You can also add any non-diseased plant or seed-free weed to make a thick mulch that will both protect the soil and add a little more organic matter.