Plant once, harvest for years

An annual crop grows, makes its harvest and dies in one season. Most vegetables are annuals, or are grown like them.

A perennial lives for three years or more. Fruit trees, nut trees, berry bushes, grapes, rhubarb and asparagus are perennials.

Perennials save you from replanting each year. Their roots hold the soil, and they need less digging. In exchange, they take time to start bearing, and a bad choice is slow and costly to fix.

The long wait

Plan perennials in year one, because they take years to pay back. Very rough waits from planting to a useful harvest:

• Strawberries: about 1 to 2 years.
• Raspberries and blackberries: about 2 to 3 years.
• Asparagus: a short first harvest in year 2, and full harvests a year or two later. A well-kept bed then bears for many years.
• Fruit trees: apples and pears often take about 4 to 6 years, and plums and tart cherries about 3 to 5 (Iowa State Extension). Dwarf apples and pears bear sooner. Full-size trees can take longer.
• Nut trees: often 5 to 10 years or more.

Rootstock is the root part of a grafted fruit tree. It largely decides how big the tree gets and how soon it bears. Dwarf rootstocks bear sooner, but trees are smaller and often need staking.

The layers of a food forest

A food forest is a planting that copies the layers of a natural woodland, using mostly useful plants. Common layers, from top to bottom:

1. Canopy: tall trees, like nut trees or large fruit trees.
2. Small trees: dwarf fruit trees and smaller nut trees.
3. Shrubs: currants, blueberries, hazelnuts.
4. Herbaceous layer: non-woody plants, like rhubarb, herbs and comfrey.
5. Ground cover: low spreading plants, like strawberries or clover.
6. Vines: grapes, hardy kiwi.
7. Roots: plants grown for underground parts, like Jerusalem artichokes.

Done well, layers use space and light more fully. Done badly, taller layers shade out everything below them.

Which layer?

Honest yields

Food forests are often sold as low-work abundance. The real picture is more mixed.

• Most fruit is low in calories and spoils fast. You need to eat, share, dry, freeze or can a big harvest in a short window.
• Nuts are high in calories and store well. They are also slow to start and can be hard to crack and clean.
• Work does not vanish. Pruning, mulching, mowing paths, watering young trees and controlling pests and disease all take time. Deer can ruin young trees without a fence.
• Yields swing. A late frost can wipe out a year of fruit. Many fruit trees bear heavy one year and light the next.

Climate decides what will thrive

Perennials must survive every winter and summer where you live, year after year.

• Hardiness zone: the USDA Plant Hardiness Zone Map shows your average coldest winter night. Pick plants rated for your zone or colder.
• Chill hours: many fruit trees need a certain number of cool winter hours, usually counted between 32 and 45 °F (0 and 7 °C), before they flower well (Clemson Extension). Warm-winter places may not have enough.
• Late frosts: a frost after bloom kills flowers. Low spots collect cold air, so avoid planting early bloomers there.
• Pollination: many fruit trees need a second, compatible variety nearby to set fruit.

Your county extension office often has lists of fruit varieties that do well locally.

Placing perennials

Trees are hard to move once planted. Think about where they will be in 20 years, not this spring.

• Put tall trees where their shade will not fall on the vegetable garden or solar panels. In the US, that usually means the north side.
• Keep trees well back from septic drain fields, wells and buried lines. Roots can damage them.
• Plant near a path you walk often, so you notice pests and ripe fruit.

Check

Summary

• Perennials come back for years, but many take 2 to 10 years to bear well.
• A food forest stacks layers from canopy trees down to ground cover and roots.
• Most fruit is low in calories. Nuts are higher in calories but slow to start.
• Match plants to your hardiness zone, chill hours and frost risk, and place tall trees where they will not shade your beds.

Next, you will look at small livestock: chickens and rabbits.