If you're planning to plant a vegetable garden this season, the best place to plant may not be in the ground. It may be above ground in a raised garden bed.
Many vegetable gardeners today use raised beds, which lift the plants and their roots above ground level. Some are simply heaps of soil, but most raised beds are wide boxes that essentially create a large container of soil six to 12 inches deep.
Introduction to Raised Bed Gardening
There are a good number of reasons to use raised beds in your garden:
You Can Choose Your Soil for a Raised Bed
Good soil builds good plants and good harvests. In a raised bed you don't have to live with the soil that came with your house. That soil may be dense, sticky clay or too sandy to hold water. It may be contaminated by hazardous lead from old paint or auto exhaust. It may be full of rocks and debris. With a raised bed, you avoid the yearly struggle with bad soil by building a container and filling it with good soil from the start.
You Don't Have to Stoop So Far
Raised beds bring the garden up where it's easier to reach for weeding and harvesting. Smart gardeners use wide timbers for the sides or even have a narrow shelf at the top edge where they can sit.
Raised Garden Beds Don't Need Tilling
In fact, you can't; in raised beds, tilling and major digging are impractical. Instead, raised bed gardeners start with good, light, organically rich soil and improve it every year by layering more compost, leaves and other organic matter on top. If you minimize the use of pesticides, microbes and other life forms in the soil will break it all down. Planting and light cultivating will mix and aerate the soil a bit, but you won't disturb the soil enough to bring buried weeds seeds to the surface. Overall, you'll have healthier soil and fewer weeds.
Soil Drains Better in a Raised Bed
In a properly constructed raised bed, excess water from heavy rains readily drains away from the plants' root zones. Plenty of organic matter in the soil will maintain a balance between holding enough water and letting the surplus escape. A layer of mulch on the surface will hold moisture and reduce watering.
You Can Plant More in a Raised Bed
Because the soil is richer and you don't need space for machinery or hoeing, you don't need to plant in rows. You can space plants more closely and get a better harvest per square foot. Raised beds are a boon to gardeners trying to get a good harvest out of a tight space.
Raised Garden Beds Warm the Soil Quicker
The soil in a raised bed will warm up quicker so you can plant earlier in spring. Of course it also will cool down more quickly in fall. But a raised bed also provides a ready structure to support a clear lid for a season-extending cold frame. Or add hoops to support translucent fabric that can add weeks to the growing season in spring and fall and shade greens from bolting in the hot summer sun, or netting to protect plants from insects and birds. A raised bed with 8- to 10-inch-high walls and a low fence of chicken wire is also an excellent defense against rabbits.
Things to Remember when Planning a Raised Bed
Size it right
Beds no more than 4 feet wide can be tended from both sides. Plan for watering. Soaker hoses are the most efficient tool for a raised garden bed.
Collect compost
You'll need a pile or bin where plant waste can break down before it goes on the bed.
Choose materials carefully
Treated lumber, railroad ties or old pallets may be contaminated with arsenic or other toxic materials. Kits are available to easily make raised beds from wood or recycled-plastic lumber.
Site it well
You can't move a raised bed once you build it, so make sure you pick a spot that gets eight hours of sun a day and is handy to the hose.
Get good soil
Order compost-rich soil by the square yard from garden centers. Tell them it's for a raised vegetable bed to get the right stuff.
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