Edible Perennials: Building Your Personal ‘Food Forest’
Once established, perennial veggies and berries keep on giving year after year.Posted May 14, 2014
With its newest public park, Seattle is planning something radical…
In the midst of its ordinary playfields, walking paths, and decorative rhododendrons, neighborhood residents will wander into a scene evoking a modern Garden of Eden: an urban food forest. Seattle’s food forest is a densely planted, multi-tiered swath of fruit and nut trees, berry bushes, edible greens, herbs, and perennial vegetables which pop up seasonally with enticing offerings. All park-goers will be welcome to pick and enjoy the produce of this ever-changing garden, located in a multi-cultural working class neighborhood just a few minutes’ bus ride from the heart of the business district.
At home, you can use the same sustainable food-supply principles by choosing plants that take root and mature productively for years with no further digging required.
“It’s as close to zero-work gardening as you can get.”
— Eric Toensmeier, author of Perennial Vegetables
Imagine beginning summer’s feast each year before you’ve set out the first seedling. For most of us, the gardening season starts with the joyous but daunting tasks of tilling, planting, weeding, and composting. We wipe off the sweat and watch eagerly for the first shoots of peas and lettuce, impatient for the fresh harvest to begin. Meanwhile, the savvy few are already enjoying their just-picked asparagus, perhaps a delicate soup seasoned with fresh herbs and sorrel, and even a rhubarb tart for dessert.
Setting up your edible perennials in their new homes takes some forethought and vision, but these low-maintenance plants will bountifully repay your investment. All perennials benefit from dressing with fresh compost each spring; choosing raised beds will keep lawn weeds from invading and the perennials from spreading. Many of these tried-and-true food plants are pricey luxuries at the farmer’s market, and can transform any dinner party or backyard picnic into a special occasion.
This seasonal delicacy provides B and C vitamins, iron, and calcium, and can thrive almost anywhere in the US except Florida and the Gulf Coast where the mild, wet winters prevent its dormancy cycle. Give some thought to the placement of your asparagus bed, knowing it will produce well for over 20 years! Soggy soil will rot asparagus roots, so choose a spot with light, well-drained soil. Asparagus “crowns” are available from garden stores or, if you’re lucky, an experienced grower whose crowns have matured enough to divide (usually after about 3 years). The first season requires patience as you allow the plants to establish themselves with no harvesting. The next season, harvest for two weeks, the following for four, and thereafter for six weeks or until the emerging spears are mostly quite thin (less than half inch in diameter). The remaining spears should be allowed to fern for the remainder of the season, and the dried ferns cut down and chopped up to use as mulch.
Once the asparagus harvest is complete in late spring, the thinning shoots are left to sprout into ferns. The fine, thick fern display is a visual treat through the summer months, but the ferns may grow 5’ or more, producing a shade effect behind the bed. For this reason, asparagus beds are often located on the north side of garden plots.
Early Spring Greens
Lemony Sorrel, the unusual but delightful Patience Dock, oniony Chives, and briny Sea Kale— all once-wild leaves are grown to eat fresh or cooked. These early spring greens are cold-hardy and prized by gardeners who crave some fresh salad greens at winter’s end. These un-hybridized greens may be more nutritionally-dense as well, historically providing a much-needed boost of fresh vitality after a long, hard winter subsisting on roots and other storage foods. Perennial greens can share a garden bed — harvest the young leaves with scissors to stimulate new growth, and cut back flower stalks to prevent seed-dropping if you’re concerned about these plants expanding their territory.
Perennial greens should be planted in areas that won’t interfere with your garden bed rotation plans. For this reason, these perennials are best situated along the margins of beds, or as ornamental borders in shrub beds. Some gardeners prefer to maintain a separate bed for early greens, since it’s easier to provide temporary cover during unexpected or unseasonal weather events.
Though its leaves are toxic, the stalks of this self-sufficient and humble plant provide spring’s first welcome fruit pies. Rhubarb does best in northern states where the average summer temperature stays around 75F. It will faithfully return year after year in an out-of-the-way corner of your garden, favoring acidic, well-drained soil and yearly supplementation with a good nitrogen source such as compost or manure. Don’t harvest any stalks the first year; the second season you may harvest lightly, and thereafter freely. If you know any local gardeners, one of them is sure to be able to spare a root crown or two to get you started enjoying your own rhubarb.
A perennial herb garden is a wonderfully compact asset to any yard or garden; many urban homes with no room for a full vegetable garden can still enjoy the beauty and flavor of fresh herbs in their landscaping or containers. Oregano, chives, and several varieties of mint can get aggressive with your garden space, so consider confining them in pots or a raised bed. Thyme, sage, lovage, and lavender are less aggressive with their roots. Some of the herbs familiar to North Americans, such as lavender, rosemary, thyme, bay laurel, marjoram, dill, and oregano are native to the Mediterranean region. These herbs grow best in soils with excellent drainage, bright sun, and moderate temperatures. Start with weed-free soil and mulch well; dinner preparation often begins with a pleasant stroll to this corner of the garden.
This thistle relative can be grown as an annual in cold climates, but in milder zones (7, 8, and 9), perennial artichokes will overwinter well and increase their yield in subsequent years. Gardeners as far north as zone 5 have successfully overwintered artichokes by insulating them well with straw during dormancy. (Find your zone here.) Artichokes will grow on a wide range of soils, but produce best on a deep, fertile, well-drained soil. The plant is deep rooted and should be planted on soils that afford adequate area for root development. When mature, the plant may spread as wide as 6’ and reach heights of 4 – 5’, so allow plenty of room between plants. Artichokes, like most perennials, love a yearly top-dressing with compost. Harvest the heads before the scales begin to open, or before you know it you will have a striking purple flower, which though lovely, is no longer edible.
Lowbush blueberries can tolerate poor, rocky soil and cold climates, requiring winter chilling for productivity: their small berries are the sweetest and most intensely flavored. Highbush varieties provide heavier yields, larger fruit, and more comfortable harvesting, making them more popular for many garden applications. Both varieties like acidic soil: test and adjust the pH (often by adding sulfur) to an ideal range of 4-5; if your soil is naturally higher than 6.5, consider choosing a different crop. Adding composted leaves or pine needles when planting helps maintain acidity. Mulch well with more leaves, pine needles, or aged sawdust from untreated wood. Patience pays off: remove fruit buds for the first two years to let the plant put its energy into getting comfortable. Locals or garden stores can tell you which variety is best for your zone.
Choose between June-bearing and ever-bearing varieties for this favorite early treat. For those with limited space, strawberries are a great choice for planter boxes or containers. They like it slightly acidic: ideal pH range is 5.5-6.5. Drip irrigation helps keep water off the developing fruit, minimizing rot. Areas with sunny days and cool nights are ideal for developing intense, sweet fruit.
Dormant bare-root raspberries can be put in the ground six weeks before the last frost. Prepare the soil with at least two inches of compost and remove all perennial weeds; if your soil is acidic, add a little lime or wood ash, taking care to keep the pH below 7 (6 is ideal). Choose a variety appropriate for your zone and tastes. Unless you want to donate your crop to the local birds, netting is a must, ideally over a simple box-shaped frame. These delicate treats are best enjoyed straight off the vine, and will make you very popular with local children!
Fruit and Nut Trees
The best return-on-effort for the gardener has to be fruit and nut trees. A mature semi-dwarf apple tree, for example, may produce over 500 apples in a season. Since these trees are a long-term investment, care should be taken in choosing the best location for planting. Fruit trees need full sun to thrive. Most also must have well-drained soil, though apples, pears, and plums are somewhat more tolerant of less-than-ideal conditions. And although fruit trees don’t like to be over pampered, they usually require some late winter pruning and thinning of the fruit buds in spring.
Urban food forests are inspired by the permaculture movement, which advocates a “new” approach to food-growing, relying on patterns found in natural landscapes to design plots that function as a complete, interconnected ecosystem. Once established, permaculture gardens need far less maintenance than conventional annually-tilled plots, and theoretically can provide an abundant and varied diet. When setting up your edible perennial beds, you can give some thought to how these new plants will relate to one another and the surrounding landscape over the coming years. For example, you could plant asparagus on the north edge of your garden with a parallel row of strawberries in the front southern edge of the bed. In early spring the asparagus flourish in full light with the strawberries not yet in leaf; when berry plants are full, the asparagus harvest is over and the ferns grow taller than the berries, getting the light they need. Plus, the showy ferns look gorgeous as a backdrop.
Interplanting perennials with annuals helps control erosion, or alternatively, expand the edges of your garden to make perennial beds around the borders. Permaculture teaches us to value marginal edges and in-between spaces, and to challenge the idea that any space is “un-gardenable.” For example, low-bush blueberries will often thrive in barren, shallow soil which most vegetables can’t tolerate. Planning pays off: if you already have productive fruit trees with grass growing in between, consider sheet-mulching the area around the fruit trees now, with the aim of planting edible perennials in your newly-fertile soil next season. Once they are well-rooted and vigorous, many of these perennials happily nestle together, naturally preventing weeds and returning nutrients to the soil through composting of foliage.
Year by year, you can build a nourishing, living landscape which uses nature’s own conservation processes to sustain your family and beautify your neighborhood.