Intensive gardening from the ground up
Source:
Master Gardener
Written by:
By Julia Habsburg
Published:
May 30, 2018
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Useful tools and supplies for building a raised bed garden are, front from left: drill, string for string line, carpenters square and recycled newspapers; rear: trimmer, safety goggles and level.

Intensive or raised bed gardening provides an excellent opportunity to have highly productive vegetable and flower gardens that are easy to maintain in convenient locations.

Gardeners can purchase premade beds or build their own. Select a sunny site for the raised bed and construct the bed at that location.

Premade raised beds can be purchased in many locations, such as garden catalogues, hardware, big box stores or the Internet. Numerous types of raised beds are available; these include grow beds, cedar beds and grow bags. These beds are prefabricated and can be set up in a matter of a few minutes to a few hours.

Building a raised bed requires tools (saw/circular saw, drill to predrill holes for screws, manual or power screwdriver, and a standard 3-inch to 4-inch level) and materials including boards.

The bed frame can be made of rot resistant lumber, manufactured vinyl products, metal with a liner, untreated landscape timbers, retaining wall block, bricks or cedar. Do not use discarded railroad timbers, as they contain creosote or pentachlorophenol, which may damage plants.

Copper naphthenate is the only wood preservative recommended for use around growing plants. Copper naphthenate is an active ingredient found in a variety of products under different names; always read product labels to know which chemicals are present in the product.

To build the bed frame, use 2-inch by 12-inch boards for additional support. Boards can be double stacked to create a depth of 24 inches.

Cut the side boards to the length and width of the desired structure. For example, a 4-foot by 8-foot bed will require the following: two 4-foot boards and two 8-foot boards. Your local lumber yard will most likely cut the boards.

Attach rust proof screws, manufactured vinyl corner braces, corner brackets or framing angle irons at the four corner butt joints to join the four pieces of framing material. Make sure your structure is square, or the measures of the angles are equal at all four corners, by using a carpenters square.

For additional stability, place stakes every few feet along the sides and corners of the boards or dig a small trench to keep the board structure level.

Once the bed frame is constructed, create the interior growing area. Remove by hand or use a weed trimmer to cut the interior grass or weeds to ground level. Place a 2-inch layer of newspaper on top of the cut area and up the sides of the frame.

Use a hose to water the newspaper and keep it in place. This layer prevents weeds and grass from growing. The newspaper will decompose over time.

If desired, line the bed with landscape fabric to prevent the wood frame from rotting and discouraging weeds. Now the bed is ready for the soil mixture.

Prepare a mixture that includes two parts of quality garden soil, one part compost or peat moss, and one part of either perlite or vermiculite. Combine the mixture evenly, preferably in a large wheelbarrow or on a tarp. For example, a 4-foot by 8-foot by 10-foot raised bed will hold about one cubic yard of a garden soil mixture.

Soil products are usually sold in 40 pound bags. This would require about 28 bags of combined products. Gardeners will need 14 bags of quality garden soil, seven bags of compost or peat moss and seven bags of perlite or vermiculite for the proper ratios.

A soil mixture containing a good garden soil will not need as much fertilizer as a soil-less mix.

A Penn State soil test kit can be used to obtain an accurate measurement of the soil's composition. Amend the soil based on the test results.

Test the soil every two to three years and amend according to the test recommendations. A soil test kit can be purchased at the Butler County Extension Office at 101 Motor Pool Way.

Once the soil mixture is incorporated into the bed frame, install the plants. Follow the planting guide you created.

Planting is much the same as in an in-ground bed. Follow the directions on your seed packets and transplants.

The bed may need to be watered a bit more often to maintain a uniform level of moisture within the growing medium. Over time you will become accustomed to your bed's water needs.

Raised bed gardening offers new opportunities for enjoying the outdoors. Making your own raised bed and growing your own vegetables brings great satisfaction to our lives.

Julia Habsburg has been a Master Gardener since 1998. Her gardening passions include growing herbs and vegetables at her Harmony home. She incorporates repurposed and decorative items into her gardens.