I was 18 years old, living in the far west of Ireland, when Paddy Daly taught me how to make my first raised bed to grow potatoes. Paddy was younger, only 15 and very quiet — but he could dig a trench quick as a plow. He came from the farm at the end of the boreen, the narrow dirt track that passed Eskeraha farm, where I worked. The Daly clan had cultivated long rows of lazy-beds in the Irish peaty soil for generations. You could see the wave-like ripples along the length of small walled fields, stretching off to the cliffs and ocean.
Paddy and I laid out the lazy-bed in a virgin field — about 40â€ wide. The middle 24â€ of the bed was covered with seaweed and rotted cow manure. Kerrâ€™s Pink potatoes were sliced and placed in two staggered rows straight on the manure. Then 12â€ grass sods were cut around three sides and hinged over with the grass face down to cover the manure and potatoes. A further outer sod or two on each side was cut and turned to lean against the first ones. Then the top was chopped to form an even surface and soil from the trenches spread to add a further layer of soil on top. As the plants emerged, more soil from the trenches was used to earth up the stems.
The lazy-bed is a time-honored way to create a rough raised bed. It works best in moist climates for fairly light soil beneath short rooted grass turf. Even then, you need plenty of stamina and skill with a long-handled spade. Nowadays, if you are starting a new garden bed or extending an existing one, it is easier to construct a permanent raised bed using lumber or concrete sidewalls.
Planning a Raised Bed
After years of experimentation, I am a true believer in contained raised beds, both in the outdoor garden and the greenhouse. 4â€ — 12â€ side walls can be constructed using rocks, concrete blocks, landscape timber or recycled plastic decking, held in place by 2â€™ lengths of rebar. A perfect size is 4 feet wide; each bed is easily accessible from pathways on one or both sides. When planting, I divide my raised beds into blocks 2â€™ long by 4â€™ wide and plant accordingly. This allows me to keep track of crop rotations and companion planting. Also, a 4â€™ wide bed is easy to water; it requires only 3 lengths of T-tape drip irrigation.
When planning a new bed, start by deciding on the best location. If you have an existing garden, your choices like mine may be limited. Still, take time to walk around your garden at different times of day to see where and how the sun strikes. Remember, many varieties of cool weather vegetables and leafy plants prefer a little shade, particularly in the afternoon. I have both East facing beds (shaded on the West) for Brassicas, greens and salads and South facing beds for hot loving varieties such as tomatoes and beans. My flowers, trees, and shrubs are mainly in full sun but I have a little shaded area for the more delicate plants.
All my greenhouses started as two 4â€™ raised beds with an 20â€ pathway between. If you plan to construct a greenhouse in future, make sure you have enough space around the beds. Raised beds can easily be protected during the winter with a variety of simple frameworks and transparent coverings.
Almost as important as sunlight to successful growing is access to a water supply — at minimum an outdoor faucet and hose. Before you start, plan how to extend or install drip irrigation and/or a gray water system. Think through any future garden expansion so you can run the supply pipes accordingly. Build beds across a slope like a mini-terrace. Drip irrigation is only efficient on fairly level surfaces.
To Dig or Not to Dig
Once you have laid out your bed and constructed the sidewalls, the next question is how to prepare the ground: should you dig or not? I was raised on double digging. For every new bed, I would move tons of topsoil and loosen the subsoil beneath. Now I let nature do the heavy lifting. Below, I describe two â€œlazier-bedâ€ approaches to raised beds: the mini-dig cover-crop method and the no-dig lasagna methods.
The Cover-crop Method
I use this method regularly whenever I need to start a new bed or rehabilitate an old one. As soon as the ground is workable, I roughly turn over the top three inches of my gravelly soil and removed any perennial weeds. I then add a 1/2â€ dressing of Alaska Humisoil (equivalent to 2â€ of compost), some alfalfa pellets from the animal feed store and a good dose of Bountea compost tea. Of the different cover crops available, I usually plant barley and white clover quite thickly: these crops grow fast, add nitrogen and organic matter and have shallow root systems.
As soon as the barley and clover are about 6â€ high, I cut the plants down to the ground with an electric strimmer. It is quite easy to turn over the top three inches of soil with the roots, smothering the cover crop. I chop and rake the surface smooth and apply another dose of compost tea. A week later, I start planting.
Green manures or cover crops are amazing. There are many types and all of them both break up the soil and add nutrients. Combine a leafy type (barley, oats, rye) with a nitrogen-fixing legume such as alfalfa, clover or vetch. Try to match the crops to your soil needs and the season of planting. I use barley and clover in the spring but if your soil is heavier and more compacted, consider using deep-rooted varieties such as rye or alfalfa in the fall.
The Lasagna Method
By far the easiest and quickest way to start a new bed is the lasagna method – smothering the weeds with cardboard or newspaper and adding a new layer of soil. It works well for heavy soil in neglected gardens and for turning a lawn into something less water guzzling. If you have particularly virulent weeds such as thistle, hoary cress or bindweed, you may need to deal with those first.
On virgin ground, lay down overlapping sheets of plain cardboard or up to 10 layers of uncolored newspaper. You can often get large sheets of used cardboard from an appliance store. Do not leave any gaps for the weeds to grow through. Water the cardboard or newspaper well, and cover with any leaves or organic matter you have around. Finally finish up with 2â€ – 3â€ of compost and topsoil.
At this point, I always apply compost tea and possibly some alfalfa pellets to get the soil life going. You can then sow a cover crop or simply plant directly into the new soil. The cardboard seems to draw worms and disintegrates over the season, allowing the plant roots to push down through to the soil beneath. Make sure you keep the bed and layer of cardboard or newspaper uniformly damp to promote breakdown.
When we work with and not against nature, gardening fulfills a profound need in us. A new raised bed is like a blank page waiting for you to create a naturally growing work of art. I remember in exquisite detail, the delicate green potato sprouts peeking out of the lazy-bed I dug with Paddy; it was deeply satisfying. Maybe that is why I ramble around my land each spring trying to find any excuse to build another raised bed.