Gardening Using Raised Beds

Norm Mofjeld, Anoka County Extension Master Gardener

Gardening in a raised bed has several advantages.  You don’t need to stoop over as much when clearing the bed of weeds, planting seeds, and harvesting vegetables.  Here are some tips that I have found when building and using a raised bed.

Raised beds come in many shapes and sizes. I have three on our back deck which are constructed out of wood and are about 30 inches high, four feet long and two feet wide.  The planting depth is 12 inches. The inside planting area has a black permeable cloth lining that holds the soil in, and the bed is supported by wooden legs.  This year my wife and I have planted tomatoes, parsley, and chives in these beds. We also planted marigolds along the front of the tomatoes to add color and help deter insects. Wire cones and bamboo sticks surround each tomato plant to give it support.

A neighbor purchased a number of metal oblong shaped raised beds that are about three feet high and several feet long and look like horse and cattle watering troughs.  The metal pieces are put together using screws and then filled with soil.

In our backyard we have four raised beds that are four feet wide by 12 feet long and one foot high. The bed should be no more than four feet wide so it can be easily reached from both sides. The walls of the bed are constructed out of plastic.  Wooden planks can also be used to construct raised beds.  When constructing the beds, I put hardware cloth at the bottom, then I covered it with cardboard and then added the soil. The hardware cloth deters moles and gophers from getting into the raised bed. We had the soil brought to our driveway, and I filled each bed with many trips using a wheelbarrow. 

I allowed a separation of four feet between the beds for a walkway that allows access with a wheelbarrow when weeding and adding soil. The walkway is grass, but mulch, or rock could also be used.

The location of the raised beds is important to allow for plenty of sunlight. Raised beds will help with drainage but don’t place them in low lying areas that are prone to flooding. Make sure the beds are placed close to a water source as the soil in the raised beds drains faster than beds placed at ground level.  I have used a sprinkler between the beds that rotates in an arc over the beds.

It is important to rotate the crops in the raised beds.  Don’t plant the same type of plant year after year in the same bed to avoid problems with pests and disease.  Maintain the soil fertility by adding compost or potting soil to the beds every year. Certain plants, such as beans or peas, are legumes which add nitrogen in the soil making it available for other plants in the future.

When planting seeds, I like to run a string from one end of the bed to the other attached to stakes on each end of the bed.  Then I plant the seeds under the string so I know the location of where the seeds have been planted.  Investing in the materials and time used in the construction of raised beds will provide you with years of enjoyment in the growing and harvesting of vegetables.