Written by Nan Sterman
Raised bed gardening is productive. Imagine this: a vegetable garden that produces a huge amount of food in a small space, takes a minimum amount of water, requires very little maintenance, and brings the plants to you, rather than you having to bed down all the way to the ground.
Sound impossible? Not at all if you garden in raised beds.
Raised beds are like giant, bottomless planter boxes filled with your favorite soil mixture. The best beds are four feet wide – about right for an adult to reach the middle. If you garden with children, 3 ½ feet better suits their shorter arms.
Bed length makes no difference, though the longer a bed, the more efficient use of space.
When my now teenage children were small, they each had their own four by four raised bed separated by a three-foot wide walkway. Three feet accommodates most wheelbarrows (and wheelchairs). Through childhood, they grew whatever they wanted in those boxes. One year, my son planted everything purple – eggplants, asters, purple sugar cane, purple leaf lettuce.
The plants didn’t matter, as long as they were purple.
Eventually, their interest in the garden waned, so we replaced the two little beds with one big bed, the length of the two beds plus the walkway. My new bed was eleven feet long and a more efficient use of the space.
Bed height is important. I’ve seen four inches tall beds, but I prefer them 18 to 24 inches tall with a 2” x 4” wood cap to sit on and set my tools on as I work. If you garden from a wheelchair, you might want something even taller.
While my beds are made of long-lasting redwood, in the school garden I manage, our beds are composite lumber made from recycled soda bottles and ground wooden palettes. They look just like wood but they will last absolutely forever. And we really liked the idea of using a recycled material.
Raised beds can be made of other materials as well; stone, rock, bricks, blocks, logs, broken concrete. If your budget is small, make temporary beds from 25-foot long straw-filled mesh wattle. Irrigation and landscape supply stores sell them for less than $30 each.
Coil the wattle into a circle or, if the circle is too large, coil it into a two-tiered circle. Fill with soil and start planting. The wattle will last for about a year, depending on your climate.
If you garden in gopher-ville or battle other root-loving critters, line the bottom of your beds with galvanized hardware cloth. The tiny mesh protects delicate root crowns from gnawing teeth, but doesn’t prevent fine roots from growing deep into the soil.
Have your irrigation in place before you set raised beds in the ground. Use drip irrigation to target water directly onto plants. Drip is far thriftier than overhead spray. It also keeps water off plant leaves where it can cause fungal diseases like powdery mildew.
Finally, fill beds with a soil mixture that is at least 30% organic matter. Skip the potting soil, it is great for pots but not for raised beds.
Add soil to within about four inches of the lip, then top with a two-inch thick layer of Black Gold Earthworm Castings and a healthy sprinkle of Black Gold Tomato and Vegetable Fertilizer. Use a hand trowel or small spade to turn the amendments into the soil.
After you plant, continue to apply a quality fertilizer throughout the growing season. Annual vegetables, fruits, edible flowers, and herbs are all hungry feeders.
So, for the biggest most beautiful plants and produce, don’t forget the fertilizer. Organic fertilizers and amendments are always better for your plants and your soil than synthetic products.
Mulch your raised beds with old straw and you’ll soon have a wonderful harvest.
Every year, refresh the soil in your raised beds by adding a thick layer of an organic compost such as Black Gold Soil Conditioner or Black Gold Garden Compost Blend.