Maine has a short growing season and there are many methods gardeners can use to extend the days to get the most of your hard gardening work. As a long-time small gardener and grandchild of Maine small farmers I have taken all these methods into consideration. With an eye on budget and ease of construction and use I have decided to construct a complex raised bed gardening system this spring. Here are my best tips for raised bed garden planning in a cold climate with limited space.
Winter Planning Tips
How much room do you have that is in full sun? The answer to this question is the key to what plants to choose, how large your beds will be and bed arrangement. Choose a spot where they can be kept long-term and will get at the very least a full days sun in half the chosen area. A hillside or house abutment will work fine for raised bed garden planning. Just remember to add drainage material like crushed stone or gravel around the uphill end and sides your frame to stop the frame from becoming flooded.
The idea of raised beds is to harness heat from the ground and protect from cool air to have plants earlier and later than nature intended. It is even possible to have them year-round in Maine’s climate with some simple tips. To prepare for this project I purchased books on the topic and previously studied plant and soil science at the University of Maine. (A link to UMaine Cooperative Extension’s raised bed gardening guide is at the bottom of this post but misses some of the topics discussed in this more in-depth article.)
Raised Bed Garden Planning: Calculate Square Footage
Choose the area in your yard for raised bed gardening in. Measure the area and use graph paper to lay it out. For my diagram I made each square is equal to two-square-feet. They do not, and for many reasons should not, be palin squares or rectangles. Make the very best use of your space by creating boxes that allow you to reach the very center of the bed from all sides and use the room as best possible. I also made sure my trusty garden cart can fit in the spaces between beds in my layout plan below—another essential of raised bed garden planning.
With everything labeled for easy reference it is time to decide what plants to order to fill the beds. In my diagram, only bed (B2) and cold frame (B3) get full sun. The others all get mostly tree-filtered sun with half a day of full sun. My beds are 4 feet wide at most. Shared walls will be used for support and will reduce building materials. A high tunnel is connected to the cold frame that will be in the sunniest spot. Tiny triangular pockets by the bench labeled (B3-B) and (B3-C) will be filled with intricate, hard to pick herbs that can be picked sitting on the bench.
The front edge of bed (B2-D) will hold squash and will be allowed to trail into the sunniest part of the yard. Daylight, moisture requirements, soil drainage, plant height and growth habit all fall into this part of the process. Knowing where to place plants is an essential part of raised bed gardening success. I sifted through both lore and science to calculate which plants will go in each spot.
Harness Companion Planting: Save Space & Increase Yields
Companion planting is a legend told to use in grade school; the native Americans were kind enough to teach invading colonists how to plant beans next to cornstalks. Beans fix nitrogen into the soil like other plants in the legumes family, and corn needs nitrogen to grow.
This relationship is true for many plants and can be practiced in raised bed garden planning to both increase yields and save space. I have notebooks filled with elaborate notes on companion planting and have boiled it down to what I feel is truly useful for common plants found and used in our Maine climate and gardens.
Choose What Plants to Grow
Once a list of desired plants is drafted for the upcoming season, it’s time to price compare and order early to save some money. Oodles of plant and seed catalogues begin to fill my mailbox in January and February. Each is filed into a binder until I find the time to flip through with my list in hand.
As a trained data analyst, I took it a step further (too far?!) and created an extensive Excel sheet detailing the plant prices, growing time, care tips and other information. This can be referred to in choosing and caring for plants. Fields include: Latin name, annual/perennial, flower color, type, purpose, care notes, soil needs, and sunlight preference.
With this color coordinated tech tool I can see what needs to be started inside and when, how many seeds are in a packet, or days to maturity for all the plants in my garden in seconds. When I have seeds left over and stored I can make note of it and not have to look for the packet. The best time to prune, transplant and how often some plants should be divided is all laid out. At this point in the season (February) the Excel Garden Notebook is looking good, but still has some work left to it.
Plant Placement and Vertical Gardening
Not detailed on my raised bed garden planning is the vertical growth on arbors and trellises. One will be based between the small square bed sections (B1-B) and (B2-B). A second will be placed on the cut-corner of (B2-C) up and over to behind the bench into (B3-C). The widest and strongest trellis will extend from (B2-A) across to (B2-D) to carry the weight of woody perennial vines. Maple poles do a fine job of making simple wooden trellises and arbors—be sure not to use too fresh of maple saplings for poles, they will send up shoots into your beds and by the time they do it will be too late to move them for that season.
Among vines on my list to plant this spring are cold hardy kiwis, mammoth melting snow peas, goji berries, red stemmed malabar, and pole beans. These plants will soar over the spaces between beds in connecting overhead arbors. Space for their roots underground and companion groundcover pants to block weeds on the surface must to be planned. To do this finer tuned planning, break each bed section down on a page of graph paper each and press lightly with your pencil—erasing will happen as your raised bed garden planning evolves.