By Jim Wuertele
Garden boxes improve early spring growth from sun energy hitting their sides. In addition, such boxes help nurture the crop, for instance:
Box Construction
Use 2x12 raw timber, rough-cut (cheaper), and set box into a shallow hole after native soil has
been removed. There is no box bottom necessary. Width can be wider than the 30 inches shown. The corners need stiffening inserts cut from the same plank and screwed (4 inch or longer coated deck screws) to both sides. Similarly, every 4 feet (or so) along the length attach a stiffener crosspiece screwed at the bottom to hold the box shape while moving into position after assembly (a 14 foot by 30 inch box weighs over 200 pounds, a two-man lift.)
Garden boxes improve early spring growth from sun energy hitting their sides. In addition, such boxes help nurture the crop, for instance:
- Controlling invasive species (moving or rooted!), especially when surrounded by gravel
- Supporting your weight with a board across the tops to sit on (during planting, thinning)
- Managing soil upgrading, tilling, worms. Limiting root invasions to/from the lawn
- Attaching support strings for crop, temporary trellis or struts, and frost cover frames.
Box Construction
Use 2x12 raw timber, rough-cut (cheaper), and set box into a shallow hole after native soil has
been removed. There is no box bottom necessary. Width can be wider than the 30 inches shown. The corners need stiffening inserts cut from the same plank and screwed (4 inch or longer coated deck screws) to both sides. Similarly, every 4 feet (or so) along the length attach a stiffener crosspiece screwed at the bottom to hold the box shape while moving into position after assembly (a 14 foot by 30 inch box weighs over 200 pounds, a two-man lift.)
A box on a slope—needing two planks on one side—will requires stiffening and aligning the long joint as well as the regular corner gussets and bottom crosspieces for minimal strength.
Timber should be wood capable of “partial burial”, and of course, chemical protection would be counter-productive! Hemlock planks shown, now over 8 years old, have dry rot in spots. Thickness insures a good life of perhaps 15 years.
Timber should be wood capable of “partial burial”, and of course, chemical protection would be counter-productive! Hemlock planks shown, now over 8 years old, have dry rot in spots. Thickness insures a good life of perhaps 15 years.
One of the advantages of the raised boxes may be obvious from the photo. The snow cover would be easy to remove with a board sweeping the top edges to get down to the last few inches of snow. Another advantage is clean walkway between beds, which is easier to keep that way over the years with enough stone mulch revealing and weakening the weeds.
Box placement requires caution about the history of older walls with painted siding. Do not place food gardens within 4 feet of those walls. Who knows how many lead paint particles have or will land at their base?
Soil handling
Fill garden boxes with a mixture of native soil that was dug out of the box hole and composted cow manure—unless your soil looks like it held buried garbage. (Be careful: coal ash is typical around older town homes. Take this ruined soil away from your garden.) Excellent soil built since the war in a grassy yard might be over 6 inches deep. If there is no natural sand below it to add, order some “washed bank sand”—not “beach sand”—and stir in a 1/8-inch layer. It takes about 3 years for any chemicals used on lawns to dissipate: plan ahead.
Box placement requires caution about the history of older walls with painted siding. Do not place food gardens within 4 feet of those walls. Who knows how many lead paint particles have or will land at their base?
Soil handling
Fill garden boxes with a mixture of native soil that was dug out of the box hole and composted cow manure—unless your soil looks like it held buried garbage. (Be careful: coal ash is typical around older town homes. Take this ruined soil away from your garden.) Excellent soil built since the war in a grassy yard might be over 6 inches deep. If there is no natural sand below it to add, order some “washed bank sand”—not “beach sand”—and stir in a 1/8-inch layer. It takes about 3 years for any chemicals used on lawns to dissipate: plan ahead.
