Based on our experience, growing plants for food is the No. 1 gardening trend today.
Tomatoes, peppers and the like are the “low hanging fruit”. We want to draw your attention to the lesser-known food crops that return year after year. Here are our top picks for perennial food, listed according to the length of service they will provide:
1. Asparagus (asparagus officinalis): An asparagus patch can be productive for up to 30 years, with little care. Many of us enjoy the fresh flavour of home-grown asparagus. Some even eat the stuff raw, right from the garden. Some tricks to maximizing production include:
- Plant in full sun.
- Dig a trench about 30 centimetres deep and plant one-year-old roots in the bottom, after you have added generous quantities of compost or rotted manure.
- As the young transplants grow, gradually fill in the trench with loose, organic-rich, weed-free soil. The trench will likely be filled to grade within four to six weeks.
- Do not pick/cut asparagus for the first two years. This is the hard part, as fresh spears appear in early spring and you will be tempted. As these spears break into leaf, they will sequester energy through photosynthesis and build up the roots of the existing plants, producing more roots and shoots.
- Harvest in year three and allow some of the last shoots to mature through the season.
2. Rhubarb (rheum rhabarbarum): Fact is after it is established, it is almost impossible to kill. There is truly no other plant that demands so little and produces so much. Plant a two or three-year-old root or a division from another plant with a minimum of two “eyes” in the ground about 30 cm deep.
Rhubarb loves rich, weed free, organic soil. We spread a couple centimetres of compost over the root zone each spring. Pull fresh rhubarb starting in the second year after planting. Remove the flower stocks as they bolt to preserve energy at the root zone and enjoy. It's prolific in a sunny location.
3. Jerusalem artichoke (helianthus tuberosus): We are not recommending you grow this as we don’t like eating it. But if you do, go for it. A member of the sunflower family, this extremely winter-hardy perennial spreads aggressively and thrives in a wide variety of soil. Nothing is much less demanding. However, to remove it from your life you will have to move to another house. It is nearly impossible to get rid of once established. Harvest ‘til the cows come home. But don’t try feeding it to them, they don’t like it either.
4. Raspberries (rubus): Plant young canes in spring about 30 cm apart in a sunny location. Choose the variety carefully as there are two categories of raspberries: summer (July) bearing and fall (September/October) bearing. Plant in weed free, organically enriched soil. Bury the canes about 10 cm deeper than the root as they will grow more roots, anchoring the plants and making them more resistant to drought. Harvest in the second year then cut them down by 2/3 and allow the new, young canes to grow up among the established canes. Generally, they produce for up to eight years before they need replacing.
5. Strawberries (fragaria × ananassa). There is nothing sweeter than home-grown strawberries. The one-year-old transplants purchased from a garden retailer are best planted in spring. Choose from June bearing or “ever bearing” which is a misnomer as they produce best in August and early September. Plant in full sun, enrich the soil with composted manure and watch them spread their tentacles wide. Plant about 30 cm apart in a square, rather than a row, for best use of space.
All perennial food plants need full sun for best results. The enemies of all perennials, indeed, all cultivated plants, are aggressive weeds like twitch grass and Canada thistle, to name just two. Cut them down or pull them as they occur in your garden.
Sit back, relax and enjoy food plants that return each spring for years.
Mark Cullen is an expert gardener, author, broadcaster, tree advocate and Member of the Order of Canada. His son, Ben, is a fourth-generation urban gardener and graduate of University of Guelph and Dalhousie University in Halifax. Follow them at markcullen.com, @markcullengardening, and on Facebook.