The benefits of perennial vegetables are many, and there are very few drawbacks.
Our local organic gardening guru, Dale Grobler, popped in for a chat recently. While he was here we got talking about how useful perennials are in the herb and veggie garden. Here are his educated thoughts on the matter:
They are low maintenance
Perennials thrive and produce abundant and nutritious crops throughout the season. They are easy to cultivate as well as being high-yield crops. Once established in the proper site and climate, perennial vegetables can be nearly indestructible. Established perennials are more likely to be more resistant to pests, diseases, drought and weeds than annuals. Some perennials even require more frequent harvesting to prevent them from becoming weeds!
They extend the harvest
Perennial vegetables often have different seasons of availability to annuals, which provides more food throughout the year. While you are transplanting tiny annual seedlings, many perennials are already growing strong and are ready to harvest.
They help to build soil
Perennial crops are amazing for the soil because they don’t need the soil to be tilled. Perennials help foster a healthy soil food web, in addition to providing a habitat for insects, fungi and other vital soil life.
When well mulched, perennials improve soil structure, organic matter, porosity and water-holding capacity. Perennial vegetable gardens build soil the way nature intended, by allowing the plants to naturally add organic matter through the decomposition of their leaves and roots.
Harvesting perennial crops
Each perennial crop is different: some you harvest the flower heads, others the leaves, berries, fruit or tubers. With leafy plants, hold back and only take a maximum of 30% of the growth, then give it some time to regrow. This general rule helps perennials to survive to see another harvest.
With tubers, make sure to save some for replanting, and the same goes for plants that grow from bulbs. Avoid harvesting all of the bulbs to allow the plants to survive. Conservative harvesting will keep your perennial crops alive.
Perennial vegetables to plant this year
Here are some of Dale’s top picks for this year, many of which he will be growing himself on his farm.
Egyptian walking onions
The Egyptian onion is unique in that it produces small bulbs at the top of its stalk, and you can use these tiny onions in your cooking (they’re similar to shallots in taste) or plant them to grow more Egyptian onions. They get their name from their peculiar growth habit: when the bulbs at the top of the stalk get bigger, the stalk gets top-heavy and bends over until it touches the ground – the little bulbs then take root, and so the plant ‘walks’ around your veggie garden from season to season. Egyptian onions continue to produce new onions even after some have been harvested.
Chives are bulbous, grass-like perennials that are easy-to-grow. To grow chives in your garden, choose a location that gets full sun or some shade. Prepare a soil that is loamy or sandy, well-draining and slightly acidic to neutral. Chives are not dependent on rich soil conditions as they can grow and thrive in most types of soils, but applying a single topdressing of nitrogen-heavy fertilisers will boost the growth.
If you have extra space in your garden, asparagus is the best perennial to grow: it proliferates and fills the space swiftly. Once you have planted asparagus, you can harvest for decades.
It is not easy to grow, though, and it is picky about where it dwells. Ensure to free the garden space of weeds and stones before planting. Asparagus is a water-dependent plant, so to meet the water demand, never skip watering and keep the soil moist. If you are successful, asparagus usually takes around 3 – 5 years to establish and mature, and around 18 months before you get your first harvest.
Rhubarb is generally consumed like a fruit. For optimal growth response, plant the seeds or plant in full sun. It is better to avoid partial to deep shade conditions as this can lead to thin stems. Although mature rhubarb plants are drought-resistant, young and developing rhubarb seedlings need moist soil and a consistent supply of water but avoid over-watering. Over-watering leads to root rot and other fungal and bacterial diseases.
Brinjals are perennial only in warmer climates (tropical and subtropical); it survives as an annual in temperate climates. Start growing brinjals indoors 7 – 10 weeks before your last expected spring frost. Fill your pots with seedling mix, sow the seeds or seedlings in pots, and cover them with additional soil. Water well and keep the seeds or seedlings moist by consistently watering. Seeds will start sprouting within 8 or so days.
From the same family as sunflowers, Jerusalem artichokes are grown for their tubers, which can be eaten raw or cooked like potatoes. The yellow flowers attract beneficial insects to the garden. Jerusalem artichokes are vigorous plants that spread by underground rhizomes and may become difficult to eradicate (which can be either a good thing or a bad thing!).
Horseradish is a perennial vegetable that is grown for its pungent roots. Horseradish is cluster-forming and belongs to the Brassicaceae family. Horseradish generally performs better in partial to deep shade conditions. Never allow the soil to turn completely dry. Keep constantly moist for better growth.