High-value vegetable crops
Which crops provide the most dollar value per square foot of garden space? The top 15 high-value vegetables are listed below. Value is based on harvested pounds per square foot, the retail value per pound at harvest time and length of time in the garden.
- Green bunching onions
- Leaf lettuce
- Summer squash
- Edible-pod peas
- Storage onions
- Head lettuce
- Swiss chard
I sit in front of the wood stove on many snowy January evenings and browse the seed catalogs that come in the mail that time of year — Baker Creek Heirloom Seeds, Comstock Garden Seeds, Johnny’s Selected Seeds and so many others — and I want to grow ten times as many vegetable varieties as I have the garden space to plant. But I know better. A little of this and a little of that cannot compete with the need for daily handfuls of pineapple tomatillos or pounds of potatoes to last the winter.
Our modest vegetable garden will only allow for small-scale indulgence in the new or unfamiliar. This past summer, for example, I used one small bed to trial five heirloom tomato varieties. I learned which varieties were most favored by the garden’s slugs. So my first advice to the novice vegetable gardener: Plant what the family loves to eat. Hold a meeting and make a list, then get on with the business of trimming the list to fit your garden space.
If space is limited, avoid growing crops like corn, melons, or winter squash (including pumpkins), all low-value crops with relatively sparse yields per square foot of garden space. Consider buying these vegetables from a local farmer, saving your garden space for the high-value crops on your family’s wish list.
Wide-row planting, often called intensive vegetable gardening, can increase a small garden’s harvest up to fifteen times over that of conventional row gardening. Instead of planting in one single row separated by wide walkways, crops are planted in blocks of closely-spaced rows that span the width of a bed. In other words, the “in-row” spacing on the seed packet is used between rows within the block as well as between individual plants within each row. A three- by two-foot bed of carrots thinned to a final spacing of three inches between plants will produce as many carrots as a single 24-foot row.
Wide-row beds are typically three to four feet in width and any length. In one bed, you might plant a block of carrots next to a block of beets, followed by a block of lettuce, and so on. It is easy to reach into each bed from the adjacent walkways and the intensive plant spacing reduces weed competition. Walkways between the beds, typically two feet wide, can be mulched with wood chips. (For help with creating wide-row beds, see last week’s column, “Looking ahead: Tips on planning your first vegetable garden,” available on the Bangor Daily News website at http://bangordailynews.com/author/reeser-manley/.)
The higher plant density in wide-row gardening demands fertile, well-drained soil enriched annually with organic matter. Extra attention must be given to watering. Here is a list of popular direct-sown garden vegetables and their recommended final wide-row spacing:
• Beets: 4-6 inches
• Carrots: 2-3 inches
• Garlic: 4-6 inches
• Kohlrabi: 7-9 inches
• Leeks: 4-6 inches
• Lettuce (head): 10-12 inches
• Lettuce (leaf): 7-9 inches
• Onions (dry): 4-6 inches
• Parsnips: 5-6 inches
• Radishes: 2-3 inches
• Spinach: 4-6 inches
• Swiss Chard: 7-9 inches
• Turnips: 4-6 inches
For crops started with transplants, use the following final spacings between plants in the bed:
• Asparagus: 15-18 inches
• Cole crops (broccoli, cabbage, cauliflower): 18 inches
• Eggplant: 18-24 inches
• Peppers: 15 inches
• Seed potatoes: 12-15 inches
• Summer squash: 18-24 inches
• Winter squash: 24-36 inches (a single row down the middle of a 4-foot-wide bed)
To save garden space, many vegetables, including tomatoes and cucumbers, can be grown vertically on trellises, nets, strings, cages and poles. Trellised tomatoes should be planted on a 24-inch spacing, climbing cucumbers planted 12 inches apart. Remember that vertically-grown plants cast more shade and should not be planted in front of sun-loving plants. Instead, grow shade-tolerant crops such as summer lettuce in the shade of trellised vegetables.
The exceptions to such intensive crop spacing are beans and peas. Both are easier to pick and less disease prone if planted as double rows in a three- or four-foot-wide bed. Finally, do set aside one small bed, or part of a bed, to try something new every year. It will lend a sense of purpose to those winter evenings spent poring over seed catalogs.
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