Perennials flower and fruit more than once and are often productive over many years, requiring less cultivation after initial planting than annuals.
Perennial systems are inherently no-dig and a key component of agroforestry systems and forest gardens. The plants tend to have deeper, more extensive roots and longer growing seasons than annuals; intercept more rainfall; and access water and nutrients from deeper in the soil.
- Reduced soil erosion
- Improved soil fertility and help to create below-ground soil webs
- Less effort and costs for farmers and growers
- Contribute to climate resilience and food security
- Some perennials are water-hungry and may require more consistent water-availability than annuals
- Pest and disease control requires thoughtful planning since they are often grown for a long time in one place and usual crop rotation practices do not apply
Perennials include fruit and nut trees and shrubs like currants and gooseberries. Shrubs are easy to propogate from prunings and apples are usually grafted to create new trees of a favourite variety.
Commonly grown perennial vegetables include asparagus, rhubarb, yams (Dioscorea species) and Jerusalem artichoke. Many kitchen herbs are perennials, including oregano, bay, mints, wild garlic and chives. Several vegetables grown as annuals are also perennial in the right conditions e.g. brassicas (cabbage, kale), some beans and potatoes.
Cereal crops derive from perennial grasses and there is an increased interest in finding perennial varieties of common grains: rice, rye and quinoa are readily available.
The Plants for a Future database lists over 1400 'tasty' perennials.
This text is based on an academic literature review by Naomi van der Velden at the Permaculture Association (Britain) as part of our collaborative GROW Observatory project.
The GROW Observatory has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 690199.