The Benefits of Raised Beds

The soil in raised beds warms faster in the spring, and stays warmer in the fall, allowing you to extend your harvest period. Because the soil is elevated above ground, drainage is also improved. Keeping the beds relatively small (not more than 4 feet wide) means that you can access the whole bed from either side, so you never have to tread on the soil within – this means you can keep the soil fluffy and loose. This type of soil is good for all plants, but particularly useful for growing carrots and other root vegetables.

 

Raised beds also produce an environment that is easy to control. You can decide exactly what kind of soil and amendments go into each one, and you can even vary the nature of the soil to suit the kind of plants you intend to grow. “Lasagna gardening” is particularly easy in raised beds, as you are continuously building the soil “up” from ground level. Similarly, Square Foot Gardening is a breeze because you’ve got a very contained area to start with.

 

Building a number of raised beds makes crop rotation in the small garden a very simple matter. With each passing season, you an alternate your crops so that they never grow in the same soil two years in a row. This can help to prevent insect pests, and some soil diseases from become established. And if you don’t want to rotate your crops from place to place in the garden (because of sunlight needs, for instance), you can rotate the soil, itself, from box to box. Be sure to add lime to at least one of your beds each year as you rotate your crops.
 

 

Because raised beds are essentially just frames full of soil, you can take advantage of their construction in several ways. It’s very easy to make an instant cloche greenhouse out of a raised bed, for instance, by securing cloche pipe in place with U-brackets fixed to the inside or outside of the box. What an ideal place to grow tomatoes!

 

By building a separate frame out of 2x2” beams, the same dimensions as your raised bed, and stapling clear plastic onto it, you can create an instant cold frame, which is perfect for germinating seeds earlier in the spring. This same frame can also have mesh screen attached in order to keep birds, cats, or other animals out of the boxes. Lightweight row cover will offer protection from insects if used in the same way, and heavyweight row cover can be used to protect plants from frost. The same frame can be adapted to hold black plastic in place when the beds are not in use, which will prevent weed seeds from germinating, and shade cloth can be used in the summer to slow the bolting of lettuce and spinach plants.

 

If all of these benefits were not enough to convince you, consider the fact that raised beds can also be placed just about anywhere. You can build them straight in the middle of a lawn area in your yard. One of our customers even built some in his dedicated parking stall at work! The ability to build your soil above ground means that tilling compacted soil is not necessary. Converting sod into workable garden space is half of the problem in new gardens, so raised beds are a great alternative.

 

When you’re first designing your raised beds, try to build them as tall and as sturdy as your budget allows. Using cedar shingles for the sides is a good idea, as it decomposes very slowly. For food gardening, be sure to avoid lumber that has been pressure treated, or treated with chemicals. It’s smart to bring in new soil to fill your raised beds if you can find quality soil at a garden centre. Obviously, the larger the beds you build, the more soil you’ll need to fill them, and this is an important consideration when planning your budget. Large quantities of new soil can be expensive, but it’s a worthy investment, as you’ll be using it for many years. It simply forms the basis from which to work forward.

 

Once again, “lasagna gardening” is made really easy in raised beds. You can start by pulling out blocks of sod from between the beds, and laying these, grass-side-down on the bottom layer of the beds. Mulched bark or gravel can then be laid in between the beds as a low-maintenance path system. Build up from the bottom of the bed with layers of new garden soil, newspaper or cardboard, peat moss, barn litter, rotted manure, compost, leaves, wood ash, grass clippings, Sea Soil, glacial rock dust, well-rinsed kelp, and straw. This will build the perfect environment for soil organisms to get to work converting all that organic matter into healthy, nutrient-rich soil. Patricia Lanza’s book Lasagna Gardening is full of useful tips on how to best build your soil from the bottom up, and is worth a read.

 

You don’t need to fill raised beds right to the top, either. In fact, leaving 4-6” empty at the top will create a slight windbreak for the soil, and will help to raise the soil temperature faster each morning.