Raised Beds Can Bring Your Garden to New Heights
by Kelsey Haigh, Landscape Designer
Free-range may be a great concept for chickens or cattle, but I’m going to make a case for containing your garden using raised beds. They’re a great way to improve the productivity of your garden.
A raised bed is a small garden plot raised above the ground. You can create a raised bed by simply mounding soil into a bed with sloping sides. However, another way, which allows you to have deeper beds, is to build the sides of the beds using wooden boards. The boards can be 10 to 12 inches high. That gives you plenty of depth for even root vegetables to thrive.
Though there is a greater initial effort to building raised beds, the benefits may warrant the investment.
The right kind of soil
Since you have to fill the beds, you have control over the type of soil that goes into them. In fact, you can buy pre-mixed soil that is designed specifically for raised beds. I like a mix that is 50% compost, 50% soil, plus organic fertilizer. This soil mix can be used for just about any veggies or flowers you choose to grow. I highly recommend a one-time addition of high-quality Bio-Char to help retain nutrients and make them more available to plant roots.
You can also manage beds individually. For example, tomatoes prefer soil with higher levels of nitrogen, phosphorous, and potassium. It’s easy to adjust the levels of these nutrients in the soil of a raised bed, giving your tomatoes an optimal place to grow.
Better soil drainage
Healthy soils are typically 25% air and 25% water. A raised bed allows water to drain through the soil. This will prevent soil compaction, or soil so dense that water and air cannot move through it. Soil compaction makes it hard for the roots of the plant to grow, affecting the plant’s overall health. Because you can better control the soil in a raised bed, you can adjust it as necessary to keep it more porous, allowing proper drainage
Less interference from rocks, roots, and contaminated soil
If you plan to garden in a place where the soil is rocky—a good deal of New England—or there is a network of tree and shrub roots just below the surface, a raised bed might be your only option. In a raised bed, there will be no rocks or roots. In other words, it will be a much more hospitable environment for the plants you want to grow. Raised beds are also a great and necessary option if your soil has a heavy clay content or you suspect could be contaminated with heavy metals or other potentially dangerous substances.
Tall raised beds can help aging gardeners keep gardening
For some, gardening is a lifelong passion. As gardeners age, bending or kneeling may become more difficult or impossible. Raised beds at least 32” tall, including those on stands, elevate the garden to about waist level and eliminate the need to bend or kneel. This can allow gardeners to continue to enjoy their passion, keep active, and have fresh garden vegetables, all of which can help maintain overall health. Be sure that these taller raised beds have adequate drainage. Trapped water is not healthy for the plants and may rot the wood.
Bringing neatness to a dirty hobby
By creating a garden of raised beds, you’ll also create a sense of order with well-defined paths, rectangular plots, and more orderly plantings. Though gardening is inherently messy, raised beds can make it seem a bit more “civilized.”
Soil in a raised bed warms faster
The instructions for many vegetables suggest planting when the soil reaches a certain temperature. Because a raised bed exposes more surface area to the warmth of the sun, your beds may reach the recommended temperature faster, allowing you a jump start on planting early spring crops. You can also speed up this process by staining the outside of the beds a darker color, which will absorb more of the sun’s heat.
Creating raised beds
Here are some simple tips to keep in mind as you plan your raised beds.
- Beds should be no more than 4 feet across. This will make it easy for you to access plants from all sides of the bed
- Consider beds that are 8 to 12 feet to maximize your growing space and be more efficient with resources
- The best choices for wood for your raised beds are rough cut (2” thick) hemlock, larch, or cedar. These woods should last 6 to 12 years. White pine is also a good choice but may last only around 5 years
- Raised beds made of stone or weathering steel will last longer, but will be more expensive
- Some large or catalog garden stores have kits you can buy to build your own raised beds. You can also hire a local carpenter to build your raised beds. If you’re handy with a saw and a hammer, you can build your own.
- Avoid pressure-treated wood. It could leech chemicals into the soil
Have fun! Enjoy the satisfaction of your new raised beds. Now you can spend your time gently tending, harvesting, and enjoying the fruits of your labor.