Bigger And Better Vegetables

Many gardeners find plants grow better in raised beds forseveral reasons:

• The soil is less compacted.
• It's easier to add compost, organic matter or other soild enhancers.
• Plants in raised beds get more sun and air circulation and can make better use of water.

"Walking in a garden causes soil compaction, which cancause problems with drainage and oxygen availability to the roots," saysDr. Michael Orzolek, professor of horticulture in Penn State's College ofAgricultural Sciences. "It's also more difficult to weed when soil iscompacted. With a raised bed, you can plant, weed and harvest without everwalking on the soil."

Raised beds can be filled with high-quality soil, and it's easy to addcompost or other organic matter. "Long-rooted plants, such as carrots, doespecially well in this environment because there are no stones to hinder theirdevelopment," Orzolek says.

Plants in raised beds get more sun and air circulation, and they can makebetter use of water. "You often can plant earlier and harvest later,because raised beds warm up early in the spring and stay warm later in thefall," Orzolek says.

Raised beds also make ideal places to grow plants that can be invasive in aregular garden -- such as mints and horseradish. But ease and convenience is thebenefit many gardeners appreciate the most. If you get a bad back and sore kneesevery year from gardening, a raised bed may put an end to those aches and pains.

"Raised vegetable beds are excellent for gardeners who have trouble withtheir backs, older people who don't have the flexibility they used to, people inwheelchairs or with other disabilities, and those who don't want to spend thesummer on their knees in the garden," says Orzolek.

How to install a raised bed

• First, choose a sunny location and decide on the sizeand shape you want. Some gardeners till the soil before building raised beds, toprovide additional room for root development.
• Construct the frame with a nontoxic building material, such as stone, cinderblocks, bricks, untreated wood or fiberglass. Avoid pressure-treated lumber andcreosote-treated railroad ties. Some garden catalogs and centers now offerraised bed frames that snap together and can easily be taken apart.
• Make sure the frame is between 12 and 16 inches high and is sturdy enough tohold together when filled with soil. If you use boards, they must be secured atthe corners with metal braces or screws, or nailed to a reinforcing block ofwood inside the corners -- if you nail into the ends of boards, they will split.
• Fill the frame with a good-quality lightweight soil mix, and add a generousamount of compost. "Avoid using soil straight from the garden," saysOrzolek. "It usually is too heavy and doesn't allow for properdrainage."

A well-constructed raised bed should last for years, and soil fertility canbe maintained by adding organic matter. "Raised beds have been used forcenturies," Orzolek says. "And with good reason -- they're better formany plants and they're easier on gardeners."