Growing a Diverse Food Forest with 20 Permaculture Plant Species

Did you know that a well-designed food forest can produce up to 10 times more calories per square foot than a conventional vegetable garden? In my own Zone 7a yard, I’ve seen yields of over 200 pounds of food annually from just a quarter-acre plot—and that’s after only three years of establishment. A diverse food forest isn’t just a pretty patch of plants; it’s a self-sustaining ecosystem that mimics natural forests while feeding you year-round. The key is choosing the right 20 permaculture species that work together, from towering nut trees to ground-hugging root crops. I’ve built this system in my own backyard, and I’ve made plenty of mistakes along the way—like planting a black walnut without checking its juglone toxicity, which killed my tomatoes for two seasons. This guide will walk you through exactly which species to pick, how to space them, and what yields you can realistically expect, so you can avoid my early blunders and start harvesting sooner.

Why 20 Species? The Power of Diversity

Monocultures are fragile. A single pest or disease can wipe out a whole row of tomatoes, but a food forest with 20 species spreads the risk across multiple plant families. In my experience, diversity also extends your harvest window—I’m picking strawberries in May, pawpaws in September, and chestnuts in November. Ecologically, different root depths and leaf shapes create a closed-loop system where nutrients cycle naturally. For example, nitrogen-fixing autumn olive shrubs feed the heavy-feeding apple trees next to them, while deep-rooted comfrey mines minerals from the subsoil and drops them as mulch. A study from the University of Missouri found that diverse perennial polycultures can reduce fertilizer needs by up to 60% compared to annual gardens. So when you’re selecting your 20 species, think in layers: canopy (tall trees), understory (smaller trees), shrub, herbaceous, groundcover, root, and vine. Each layer fills a niche, and together they create a resilient, low-maintenance food system.

Selecting the Right Plants for Your Climate and Soil

Before you buy a single plant, test your soil. I use a simple $15 Luster Leaf Rapitest kit to check pH, nitrogen, phosphorus, and potash. Most food forest species prefer a pH between 6.0 and 7.0, but blueberries demand acidic soil (4.5–5.5). If your soil is heavy clay like mine was, you’ll need to amend with organic matter—I added 3 inches of compost and 2 inches of aged wood chips per 100 square feet, then tilled it in a year before planting. Your USDA hardiness zone determines which species survive winter. I’m in Zone 7a (minimum 0°F), so I can grow figs and pomegranates, but a friend in Zone 4 has to stick with apples, plums, and hazelnuts. Check your zone on the USDA map, then match species to your chill hours (the number of hours below 45°F needed for fruit trees to break dormancy). For example, ‘Fuyu’ persimmons need only 100 chill hours, while ‘Red Delicious’ apples need 800. Pick cultivars that match your local conditions—your county extension office can provide a list.

The Canopy Layer: Nut Trees That Anchor Your Food Forest

Nut trees are the backbone of any food forest. They provide shade, habitat, and a high-calorie harvest that stores for months. I’ve planted four canopy species in my own yard, and here’s what works:

• Dunstan chestnut (Castanea dentata × mollissima): Plant two for cross-pollination, spaced 30–40 feet apart. In my Zone 7a, they start bearing in year 4, and by year 8 I got 50 pounds per tree. The nuts are sweet and easy to peel. Downside: they need full sun and well-drained soil—mine struggled in a low spot until I built a raised mound.
• ‘Kanza’ pecan (Carya illinoinensis): A northern-adapted cultivar that handles Zone 6–8. Space 40 feet apart. Expect 30–60 pounds per tree after 10 years. Pecans require a pollinator—I planted ‘Kanza’ with ‘Lakota’ for overlap. Beware of scab fungus; ‘Kanza’ resists it better than older varieties.
• ‘American’ hazelnut (Corylus americana): A shrubby nut tree that stays under 15 feet. I spaced mine 8 feet apart in a hedgerow. They produce 5–10 pounds per bush by year 5. Hazelnuts are self-fertile, but yields double with a second variety like ‘Jefferson’. Watch for Eastern filbert blight—choose resistant cultivars.
• Black walnut (Juglans nigra): Only plant this if you have space and tolerance for juglone toxicity. It kills tomatoes, peppers, and potatoes within 50 feet. I lost a whole bed before learning. But the nuts are delicious, and the wood is valuable. Space 50 feet apart, and expect 20–40 pounds after 15 years.

Pro tip: Plant your nut trees in the fall so roots establish over winter. Water deeply the first two summers—I used a soaker hose for 2 hours every week unless it rained.

Understory Fruit Trees: Shade-Tolerant Producers

Under the canopy, you need trees that handle dappled light. I’ve had great success with these four:

• ‘Fuyu’ persimmon (Diospyros kaki): A non-astringent variety that ripens in October. Space 15–20 feet apart. My tree produced 30 pounds in year 4. It needs well-drained soil and moderate water—too much causes root rot. In Zone 7, no winter protection needed.
• Pawpaw (Asimina triloba): The only temperate custard apple. Plant two different clones (e.g., ‘Sunflower’ and ‘Overleese’) for pollination, spaced 10 feet apart. They bear in 4–5 years, yielding 10–20 pounds per tree. Pawpaws dislike full sun when young—I planted mine under a black walnut (they’re juglone-tolerant).
• ‘Regent’ serviceberry (Amelanchier alnifolia): A small tree (15 feet) with berries that taste like blueberries. Space 12 feet apart. I get 5–8 pounds per shrub by year 3. Birds love them, so netting is essential—I used a ¼-inch mesh over PVC hoops.
• ‘Illinois Everbearing’ mulberry (Morus alba): A fast-growing tree that fruits from June to August. Space 20 feet apart. Mine produced 15 pounds in year 2, and by year 5 it was 40 pounds. The berries stain everything—plant away from paths. No pest issues in my area.

Space these trees 10–15 feet from the canopy to avoid root competition. I mulched each with 4 inches of wood chips, keeping it 6 inches from the trunk to prevent rot.

Shrub Layer: Berries and Nitrogen Fixers

Shrubs fill the gap between trees and groundcover. They provide berries, fix nitrogen, and attract pollinators. Here are my top five:

• ‘Bluecrop’ blueberry (Vaccinium corymbosum): Needs acidic soil (pH 4.5–5.5). I planted three in a raised bed with peat moss and pine bark, spaced 4 feet apart. They yield 8–12 pounds per bush by year 6. Net against birds—I lost half my crop one year.
• Goumi berry (Elaeagnus multiflora): A nitrogen-fixing shrub with tart red berries. Space 6 feet apart. Mine produced 5 pounds in year 3. It’s drought-tolerant and handles partial shade. The berries make excellent jam.
• ‘Adams’ elderberry (Sambucus canadensis): Grows 8 feet tall, with clusters of black berries high in vitamin C. Space 5 feet apart. I harvested 10 pounds from two bushes in year 4. Cook before eating—raw berries cause nausea. Prune old canes to the ground each spring.
• ‘Red Lake’ currant (Ribes rubrum): A compact shrub (4 feet) that fruits in July. Space 3 feet apart. Yields 4–6 pounds per bush. Currants need consistent moisture—I mulched heavily with straw. Watch for powdery mildew; ‘Red Lake’ is resistant.
• Autumn olive (Elaeagnus umbellata): Another nitrogen fixer, but invasive in some areas. I only recommend it if you have poor soil and can manage its spread. Space 8 feet apart. The berries are high in lycopene and attract birds. I prune to keep it under control.

Plant shrubs in a crescent around your fruit trees, leaving a gap for airflow. I water them with a drip line—1 gallon per hour for 30 minutes twice a week in dry spells.

Herbaceous Layer: Perennial Vegetables and Medicinals

This layer provides greens, stalks, and roots year after year. I’ve chosen four reliable species:

• ‘Jersey Knight’ asparagus (Asparagus officinalis): A male hybrid that produces thick spears. Plant 1-year-old crowns 18 inches apart in rows 4 feet apart. Don’t harvest the first year—let them fern out. By year 3, I got 1 pound per crown per season. Expect 15–20 years of production. Keep weeds down with 3 inches of straw mulch.
• ‘Victoria’ rhubarb (Rheum rhabarbarum): Space crowns 3 feet apart. Rhubarb thrives in partial shade. I harvest stalks from April to June—about 2 pounds per plant. Remove flower stalks to keep energy in the roots. Don’t eat the leaves (oxalic acid).
• French sorrel (Rumex scutatus): A lemony perennial green. Space 18 inches apart. It self-seeds prolifically—I thin to keep it from taking over. Harvest leaves from spring to fall. It’s drought-tolerant and handles poor soil.
• Egyptian walking onion (Allium × proliferum): A perennial onion that forms bulblets on top. Plant sets 12 inches apart. The bulblets fall over and “walk” across the garden. I harvest green onions in spring and bulbils in summer. No pest issues.

Plant these in the sunniest spots under the canopy. I interplant asparagus with rhubarb to maximize space—the asparagus emerges early, then rhubarb fills in later.

Groundcover and Root Crops: Maximizing Every Inch

Groundcovers suppress weeds and produce food without competing with taller plants. Root crops store energy underground. My top picks:

• ‘Beauregard’ sweet potato (Ipomoea batatas): A warm-season perennial in Zones 8–10, but I grow it as an annual in Zone 7. Plant slips 12 inches apart in rows 3 feet apart. After 120 days, I dig up 3–5 pounds per plant. They need full sun and loose soil—I grow them in raised beds.
• Groundnut (Apios americana): A native vine with edible tubers. Plant tubers 2 inches deep, 18 inches apart. They climb on trellises or shrubs. After two years, I harvest 2–3 pounds per plant. The tubers taste like potatoes with a nutty flavor. They fix nitrogen too.
• ‘Stampede’ Jerusalem artichoke (Helianthus tuberosus): A sunflower relative with knobby tubers. Plant tubers 4 inches deep, 24 inches apart. They spread aggressively—I contain them in a buried 18-inch-tall plastic barrier. In year 2, I got 5 pounds per plant. Harvest after frost for sweetness.
• ‘Ozark Beauty’ strawberry (Fragaria × ananassa): An everbearing variety that fruits June to October. Space 12 inches apart in a matted row. I get 1–2 pounds per plant from June through frost. Mulch with straw to keep berries clean. Replace after 3 years for best yields.

These plants thrive in the understory’s partial shade. I use sweet potatoes as a summer groundcover under young fruit trees—they shade the soil and suppress weeds.

Vines: Vertical Food Production