Spring Garden Prep
Whether you’re growing in a raised bed or in the soil, the surface of your garden might look like this is in the spring:
A typical garden plot at one of Peterson Garden Project’s community gardens.
Left uncovered throughout the winter, soil can take on a grayish appearance and pebbles may graze the surface. Weeds will start to pop up and the soil level may be a little low. Although you can plant directly in a bed like this, your plants will fare much better if you take a few steps to prep first.
1) Remove weeds by hand-pulling or using a tool such as a dandelion weeder or Cobrahead weeder. It’s important to lift weeds fully out of the soil so the root is not left behind – weeds are very hardy and may re-grow if the root is left intact. If you are having difficulty pulling weeds, try moistening the soil first with a little water, or wait a day or two after it rains. Weeds come out of the soil much easier when it is a little moist. Be sure to shake off excess soil from the roots back into the bed.
2) Although conventional farmers typically till or turn over the soil before planting, this is not necessary for a raised bed, and new research suggests that tilling disrupts soil structure and the microbe and invertebrate communities within it. Instead, rake the surface of the soil to create a finely textured surface for direct-seeding. If you’re adding compost, this is the time to do it! Compost can be applied to the soil surface and raked in the top few inches. Be sure to break up any clumps and distribute evenly through the bed.
3) How much compost to add? Compost is typically recommended to be applied at a rate of 1″. Use the soil calculator from Gardener’s Supply to help figure out how much to get. In our 4’x8′ raised bed, we need 3 cubic feet of compost. Compost is typically sold in 1-cubic foot bags, so we’ll add three bags of compost. Keep in mind that compost should not be considered fertilizer. Growing vegetables require a lot of nutrients and you will likely need to add some fertilizer in addition to compost. Is it possible to add too much compost? Absolutely! The healthiest garden soils typically contain around 10% organic matter.
4) If the soil level in the raised bed is lower than 2″, add soil, not compost. Unless the soil is very poor, adding too much compost can have a negative effect on plant health. To determine how much soil to add, measure from the top of the wood frame of the raised bed to the top of the current soil level, and put that amount in the “depth” field of the soil calculator. Why does the soil level appear to decrease over time? As the organic matter in the soil breaks down, a large portion of the carbon from the soil is released into the atmosphere. Erosion may also be a factor unless the bed was covered with straw, mulch or burlap over the winter. Adding soil to a raised bed increases the capacity to:
-retain moisture
-provide growing space for roots
-provide living space for more beneficial microbes and invertebrates
-help stabilize temperature at the root level
It’s a good idea to have at least 6″ of soil for most annual vegetable plants. Growing in containers? Plants grown in containers do better with a lightweight potting soil or specially-formulated soil-less mix for container gardening.
written by Breanne Heath