Caroline Lewis is a Portland, Oregon, urban gardener whose company, Verdura Culinary Gardens, is dedicated to helping gardeners be more successful at raising their own organic vegetables. A licensed landscape contractor, Verdura installs raised bed gardens including trellises and drip irrigation systems, creates custom year-round planting plans, and offers vegetable garden coaching and maintenance programs. Caroline welcomes your comments and can be reached at caroline [at] verduragardens.com.

High yield, high benefit

Which edibles to plant in a small space?

By Caroline Lewis

March 30, 2010

Our friend Todd wrote us: “I only have a certain amount of space available to plant veggies. While certainly I would grow some items just to have them fresh, I would also like to save as much money at the supermarket as possible with my little square of dirt. What are some high-cost, high-yield-per-square-foot veggies? On the flip side, what are some huge space-takers with relatively low yields?”

Here are some thoughts on these questions. Please note this list is by no means complete!

Expensive vegetables

By “expensive,” we’re referring to what you pay at the grocery store for vegetables. Here are some of our favorites that do well here in the Pacific Northwest, cost a lot at the store, and have good yields:

• Heirloom tomatoes, including slicing and cherry varieties, are our number-one request from clients. Why pay $4 for a little basket of cherry tomatoes or $5 a pound for heirlooms trucked up from California? Everyone knows they taste better home grown and just picked.
• Basil and other herbs like thyme and tarragon are very expensive in those little plastic packages.
• Cipollini onions and shallots are workhorses in the kitchen and often cost up to $8 a pound.
• Leeks are usually priced at several dollars a pound and are easy to grow.
• Chiles, from pasillas to habañeros, are prolific and much tastier home-grown.
• Asparagus is a commitment; it takes three years to become fully established, but the sweet flavor of home-grown asparagus is not to be believed. Plus, it’s really cool to watch it grow.

It’s fun to watch the asparagus grow.

High-yield vegetables

Many clients ask us to focus on growing high-yield vegetables and fruits so they can maximize the productivity of their gardens. A few examples of these are:

• Green beans and peas. The more you pick these legumes, the more they’ll keep giving, often over many weeks.
• Basil. As long as you don’t let it flower, basil is remarkably productive. We have been known to make and freeze three or four batches of pesto over a summer from each plant.
• Blueberries. Once established, these hardworking bushes produce berries for years.
• Leaf lettuce, kale, chard, and spinach. If you harvest these crops by just removing the outer leaves — rather than uprooting the entire plant — they will provide greens over a much longer period of time.
• Carrots. Home-grown carrots are incomparably sweet, nutritious, and easy to grow. And 16 can be grown in just one square foot.

Vegetables to skip (unless you have lots of space)

• Corn is space- and nutrient-intensive, and only makes sense in large gardens.
• Cauliflower and celery are both relatively tricky to grow for home gardeners.
• Winter squash is fun, but takes up a lot of space for a relatively small yield — usually about two squash per plant.
• Like corn, potatoes are not particularly economical to grow, especially the first year, as they require their own extra-deep frame. But we grow a lot of them anyway. There’s something incomparable about the taste, texture, and fun of growing your own potatoes that tends to negate the cost issue.
• Green onions are inexpensive at the store, and it always seems a shame to pull immature onions out of the ground when we think of how big they’ll be in a few more months.

Cost and productivity aside, if you’ve never grown the following crops at home, please give them a try because they are SO much better than anything you’ve ever bought at the store: peas, broccoli, leafy greens like chard and kale, green beans, carrots, lettuce, asparagus, peppers, tomatillos, and of course tomatoes.

And finally, remember the number-one way to maximize productivity in a garden of any size is careful planning. You can grow four tomato plants in cages in a four-foot-square garden. Or, in that same space, you can grow a bumper crop of spring peas (64 plants), then tear them out and grow your four tomatoes on a trellis. Oh, plus 64 carrots, four bell-pepper plants, 18 beets, and eight lettuces. And that’s just the summer planting . . .