Mar. 29 column: Raised beds

Here is a link to my column in today’s edition of The Spokesman-Review. Raised beds keep garden tidy, give roots room to thrive. It’s about one of my favorite topics, raised-bed gardening. You can also read my column below.

Raised beds are very popular in our own veggie garden. At this point, we have 26 of them! Most are 3′ by 8′. Two are 3′ by 16′ for housing our red and golden raspberry canes. And a couple of years ago, we expanded our garden a bit. This meant the addition of three more raised beds that are 4′ by 16′ (pictured above).

In today’s column, I discuss the best attributes of raised beds and the materials for constructing them. I hope you’ll find it useful. And who knows? Maybe this will be the year you switch to them in your garden!

Column:

by Susan Mulvihill

In 1981, I read an article that significantly impacted the way I had been growing vegetables. The topic was raised-bed gardening. I’d never heard of it but it sure sounded appealing. Thirty-four years later, there are 26 raised beds in my garden.

What is it about raised beds that’s so appealing?

• The soil stays loose in the beds because you walk around them instead of across them. Research has shown that one of the main reasons plants fail to thrive is due to root compaction. That happens when a gardener walks right up to, or in between, the plants. This makes it difficult for the roots to take in moisture and nutrients.

• Since the sun hits the sides and the tops of the beds, the soil warms up earlier in the spring. This gives gardeners the opportunity to plant a little earlier.

• Raised beds add a more elegant aspect to the vegetable garden. I think nothing looks prettier than a patch of well-tended veggies. And when they’re arranged in tidy beds, you’ve got a winner.

• If you live in a region where your soil is mostly comprised of rocks, build a raised bed. Fill it with soil from a landscape-supply business and you’ve got an instant garden.

• You can plant crops more intensively in raised beds. For example, I grow corn plants spaced one foot apart in all directions. I don’t follow the conventional spacing of 3 feet between rows and 18 to 24 inches between each plant. Yet my corn harvest is always abundant.

That 1981 article showed unframed beds where the soil had been mounded up about 10 inches. My husband and I copied this design initially but soon discovered the soil erodes during the growing season. Having to re-mound the beds each year was backbreaking work.

We quickly switched to framing our raised beds with lumber and haven’t looked back since. We use 2-inch by 10-inch framing boards, which are very sturdy. They create a nice, deep bed for growing all types of veggies. Four-inch decking screws securely fasten each bed’s corners. Most of our beds are 3 feet wide by 8 feet long and they typically last 10 to 12 years.

We use untreated wood to build our beds. Studies have shown that the chemicals used in pressure-treated wood and railroad ties will leach into the soil. Unfortunately, vegetable roots will absorb those chemicals. We just buy standard lumber which is usually fir or larch. Cedar and redwood last longer but are more expensive. It’s all a matter of what your budget will allow. Other options include using recycled-plastic lumber or purchasing raised bed kits.

Raised beds can be any size or shape you want — squares, rectangles, triangles, octagons. But narrow enough so you can reach across the beds to tend them without having to stand or kneel on them.

They can also be as tall as you desire. I’ve tried different depths and find 10 inches to be the most ideal for my purposes. If you go with a much taller bed to eliminate bending or kneeling, you can fill the lowest section with materials such as pine cones, rocks or broken concrete so you won’t need a huge quantity of soil. Just remember that most vegetable crops need several inches of soil depth for root growth.

Consider giving raised beds a try. They’ve enabled me to grow a large, productive and beautiful garden each year.

Susan Mulvihill is co-author, with Pat Munts, of “Northwest Gardener’s Handbook.” Contact her at inthegarden@live.com or find her online at facebook.com/susansinthegarden or susansinthegarden.blogspot.com.