Most edible plants are gifts that return to you more than it costs to buy and grow them. Perennial vegetables are the gift that keeps on giving, season after season and year after year.

Annual crops are planted each season, whereas perennial crops are planted once and keep coming back year after year.

When planning your vegetable garden for the new year, consider making space for more than your usual favorite annual plants. Perennial vegetables of North America — and beyond — include herbs, and flowers, and of course, fruit and nut crops. These are amazing plants that yield the greatest return on investment, (ROI), for you plant it once and enjoy it for years to come. 

When we first started growing blueberries, we were amazed to learn that they can produce for up to 30 years or more. The harvest from each plant will pay for itself in the first year of production. Thereafter, they just keep on giving, year after year.

We began in earnest a couple years ago to grow more perennial food crops. For starters, we selected “Ebony Knight” asparagus along with tree collards. We also planted, by seed and transplant, an entire patch of dandelion, and expanded our raised beds to include Walking Stick kale, and Walking (Egyptian) Onions.

Our chives, lemon balm, rosemary, sage, and thyme have come through many winters so far as they reemerge with fresh foliage come spring.

All plants are faring well into our Zone 7A December along with some choice selections of winter annuals: lettuce, radicchio, mizuna, kale, Swiss chard and perpetual spinach. With proper care and frost covers, the annuals should carry on into spring. Nothing beats a fresh garden salad served up in January!

Here’s why a gardener will want to plant more perennial vegetables.

Benefits of Perennial Vegetables

Established Perennial Plants Are Low Maintenance

• No annual planting or annual tilling
• Virtually indestructible despite neglect
• More resistant to pests, diseases and weeds
• Less watering and weeding
• Lower impact on the environment due to less maintenance input

Perennial Vegetable Crops Produce More as They Grow

• Increased harvests from year to year
• Expand the harvest season 
• Produce during the off season for annuals
• Many perennial vegetables have edible leaves and flowers.  
• Some perennial crops are prolific and the more you harvest, the more they produce

Perennial Vegetables Build the Soil

• Root system anchors soil for erosion control
• Draw up more nutrients into the topsoil
• Encourages good types of fungi
• Improves organic matter
• No tilling to disturb the soil microbiome

More Benefits of Perennial Crops

1. BENEFICIAL INSECTS – a perennial crop can provide a place for beneficial insects to hide and reside
2. RESISTANT – most perennial crops are more resistant to pests, disease, drought and even weeds.
3. ABUNDANT – the more you harvest a perennial crop the more it tends to produce

You may not realize it, but you might be growing perennial crops that you’re treating like annuals. Potatoes are one form, and even a tomato can be grown year round as a perennial, depending on your location.

But for the cold weather, blights and other pests, annual rotations are necessary, which can render some perennials to be more like annuals. Natural perennials most gardeners treat as annuals include the brassicas like broccoli and kale. When these plants bolt and come into flower we usually call it quits. But there are other options.

Perennial Vegetables to Grow in Zone 7A

These are the perennial vegetables and herbs we’re growing in USDA growing zone 7A.

• Artichoke / Globe Artichoke – Cynara cardunculus var. scolymus
• Asparagus – Asparagus officinalis
• Chives – Allium tuberosum
• Collards – Brassica oleracea var. viridis
• Dandelion – Taraxacum officinale and related Chicory species
• Garlic – Allium sativum
• Garlic Chives – Allium tuberosum
• Kale – Brassica oleracea spp.
• Horseradish – Armoracia rusticana
• Jerusalem Artichokes aka Sunchokes – Helianthus tuberosus
• Radicchio – Cichorium intybus L
• Ramps – Allium tricoccom
• Rhubarb – Rheum x cultorum, AKA wild leeks
• Sorrel, French Sorrel – Rumex acetosa, primarily used as an herb in cooking and to accent salads and soups
• Tree Collards, AKA: ‘Walking Stick Kale’, or Tree Kale – Brassica oleracea acephala
• Walking onions – Allium × proliferum
• Watercress – Nasturtium officinale

Common Perennial Herbs – listed alphabetically

• Comfrey – Symphytum officinale 
• Lavender – Lavandula stoechas L. – a favorite perennial herb for aromatic, cosmetic and therapeutic benefits, (learn how to make lavender oil).
• Lemon Balm – Melissa officinalis* –  
• Mints and Mint Family e.g. Agastache, Monarda species, Chocolate, and Catnip. – Mentha spp.* 
• Oregano – Origanum vulgare L. – a perennial herb with edible and medicinal benefits
• Rosemary – Rosmarinus officinalis L – another perennial herb with culinary, cosmetic and medicinal benefits
• Thyme – Thymus vulgaris – a favorite perennial herb native to Eurasia, another favorite culinary herb with medicinal benefits

*Some invasive species such as mints need their own special space or planting in containers.

Perennial Edible Trees of North America 

Most people in the US and North America don’t usually think of trees when it comes to perennial crops other than fruit and nuts. However, in many parts of the world, such as India, Malaysia and the Philippines, it’s common to step out into ones yard and pluck some moringa, tamarind and other tree leaves to go into the pot of chicken soup. 

Many fruit tree fruits are used as vegetables if eaten when green, such as papaya, plantain (bananas) and mango. The citrus tree leaves and also the berry bush leaves can be dried and used as herbal tea, and the dried fruit is also often used to create tea blends along with the leaves.

Opening up to some of the many less common foods to grow, especially perennials, will help with food security for your family. As others discover what you’re doing, more will also do it such that entire generations are awakened to the many, many benefits available from Mother Nature.

Edible Trees and Shrubs to Know for Survival Food (and Medicine)

• Beech, American, Fagus grandifolia – 
  • inner bark is edible,
  • leaves, when young and soft
  • nuts:
    • edible roasted with skin removed, (contains a poison called fagin)^[1]http://www.jodrugs.com/toxicologies/3598-plants-fagus.aspx^[2]https://practicalselfreliance.com/foraging-beech-nuts/
    • pressed for oil
  • seeds are sweet and edible and can be eaten or crushed into a butter. 
• Birch, Betula pendula & Betula lenta:^[3]https://www.americanforests.org/magazine/article/edible-trees-foraging-food-forests/
  • inner bark is edible:
    • raw
    • boiled
    • ground into flour
  • essential oils have medicinal and healing properties
• Linden, American, Tilia americana – Northeastern US & Midwest US:
  • flowers
  • leaves, young
  • sap
  • shoots
• Linden, Little Leaf, Tilia cordata – Northeast & Central North America: 
  • leaves, young 
  • buds
  • shoots
• Maple, Acer^[4]https://www.americanforests.org/magazine/article/edible-trees-foraging-food-forests/ –
  • bark, inner:
    • cooked
    • raw
  • leaves, young
  • sap for water and syrup
  • seeds
• Moringa – leaves
• Mulberry, Morus rubra – Northeastern US:
  • mulberries (fruit) – many uses similar to blackberries and raspberries
  • leaves,  only young curled leaves – added to soups and salads
  • shoots – only young and tender shoots
• Rose of Sharon, Hibiscus syriacus – Originally from China; now global:
  • flowers – fresh in salads; dried for tea 
  • leaves – fresh in salads and sandwiches; mucilaginous properties good for thickening soups and sauces; dried for tea

SOURCES: EarthPlanet.org

You can find more on edible tree leaves, bark and blossoms here.

Perennial Vegetable Growing in Popularity

One of the easiest perennial edibles we’re adding to our garden this year is “Purple Tree Collards” (Brassica oleracea var. acephala).

There are green leaf varieties, but the purple is tastier, more tender plus adds a nice touch of color to the gardenscape.

You can read more on tree collards here.

Perennial Vegetables by Grow Zone

Below is a list of perennial vegetables in accord with their US Hardiness Zones. It is an abbreviated list derived from the “Bible” on the subject entitled Perennial Vegetables by Eric Toensmeier . All plants listed below are available for purchase online.

There are fewer edible plants that can survive the colder climates of North America as perennial crops. But we’ve included a list of perennial nutritious crops that can survive cold climates with some protection.

Perennial Vegetables for Zones 1 to 3

• Daylily, Hemerocallis spp.,
• Rhubarb, Rheum x cultorum
• Sunchoke, AKA Jerusalem Artichoke, Helianthus tuberosus,

May Be a Perennial Plant With Protection:

• Garlic chives, Allium tuberosum
• Asparagus, Asparagus officinalis
• Giant Solomon’s seal, Polygonatum biflorum var. commutatum
• French sorrel, Rumex acetosa
• Dandelion, Taraxacum officinale

Zone 4-7 Perennial Vegetables

• Asparagus, Asparagus officinalis
• Chicory, Cichorium intybus
• Chinese yam, Dioscorea opposita
• Dandelion, Taraxacum officinale
• Daylily, Hemerocallis spp.
• French sorrel, Rumex acetosa
• Garlic chives, Allium tuberosum
• Giant Solomon’s seal, Polygonatum biflorum var. commutatum
• Ramps, Allium tricoccum
• Rhubarb, Rheum x cultorum
• Sunchoke, AKA Jerusalem Artichoke, Helianthus tuberosus
• Turkish rocket, Bunias orientalis
• Onion, Egyptian walking onion, Allium x proliferum – hardy to zones 3-10^[5]https://hort.extension.wisc.edu/articles/egyptian-walking-onions/
• Watercress, Nasturtium officinale

Perennial Vegetables in the Warmer Zone 6 and Zone 7 (or with protection):

• Broccoli, perennial (includes ‘Calabrese’) – Brassica oleracea botrytis
• Kale, branching bush (like ‘Kosmic’) – Brassica oleracea ramosa
• Leek, sweet perennial – Allium ampeloprasum
• Onion, Egyptian walking – Allium cepa proliferum
• Shallot – Allium cepa aggregatum
• Tree Collards, AKA: ‘Walking Stick Kale’, or Tree Kale, Brassica oleracea acephala (good for down to 20℉)*

*With protection below 20-30℉ / -6.7 to -1.1℃

You may be interested in this article on what vegetables to plant in fall.

Zone 8 and Zone 9 – Southeastern US (add to the above listings)

• Artichoke, purple Sicilian globe – Cynara scolymus
• Broccoli, perennial (includes ‘Calabrese’) – Brassica oleracea botrytis
• Kale, branching bush (like ‘Kosmic’) – Brassica oleracea ramosa
• Cardoon – (artichoke-like) Cynara cardunculus
• Leek, sweet perennial – Allium ampeloprasum
• Onion, Egyptian walking – Allium cepa proliferum
• Shallot – Allium cepa aggregatum
• Tree Collards, AKA: ‘Walking Stick Kale’, or Tree Kale, Brassica oleracea acephala

Perennial in warmer parts of Zones 8-9 or with protection:

• Banana, Rajapuri – Musa x paradisica
• Capsicum, sweet pepper, perennial – Capsicum annum
• Malaba Spinach – Basella alba
• Spinach, New Zealand – Tetragonia tetragonioides
• Spinach Okinawa – Gynura crepioides
• Sweet potato – Ipomoea batatas

Perennial Greens

• Walking Stick Kale, Tree Collards – Brassica oleracea acephala
• Chinese cabbage, tatsoi and mizuna – Brassica rapa
• Collards – Brassica oleracea var viridis*
• Chicory (includes radicchio, escarole, endive) – Cichorium intybus
• Okinawa spinach – Gynura crepioides
• Longevity spinach – Gynura procumbens

Gardening in the woods, much of our garden is in partial shade, so greens do well for us. But if you’re in full sun, you may still be able to grow shade tolerant edible plants with the use of shade cloths for protection from full sun in summer and frost cloths in winter in some of the higher zones.

One of the easiest perennial edibles a gardener can add to their garden is “Purple Tree Collards“ (Brassica oleracea var. acephala). There are green leaf varieties, but the purple leaves are tastier and more tender. These plants are hardy to only 20ºF so they’re not well suited for our grow Zone 7, but we have a solution.

There are workarounds which can be applied to these and other relatively tender perennials. We’ve done this for years with our ‘tropical” gynura procumbens.

Overwintering Tender Perennials

• Grow perennials in a container and bring indoors for the cold weather. 
• Set containers back out when the weather warms.
• Take cuttings and root them inside small pots for transplanting in the spring.
• Repeat every year.
• Note: A heated hoop house or greenhouse is a big help.

Those who fancy having a permaculture garden can begin rotating from annual crops to perennials. We’ve mainly focused this article on vegetables and herbs here, however you can also add perennial flowers, fruiting vines, bushes, and trees. Most perennials are outstanding plants for attracting pollinators offering flowers you needn’t plant every year. Many permaculture plants perform well as ornamentals like knockout roses.

There will always be space in our garden for annuals like beans, okra, cucumbers and, of course, the potato and tomato varieties. But we’re also keen to experiment with more perennial plantings and reap the benefits of lower maintenance, more efficient yields, and soil enrichment, and beauty.

Best to plant once and reap many times whenever possible to minimize waste and maximum production.

Speak of that, we’ve definitely needed to add to our asparagus crop, and finally did that this spring. Here’s Coleman on growing asparagus.

Check out what vegetables to grow in winter.

Growing Asparagus – a Wonderful Perennial Vegetable

To plant a garden is good for a season. To plant an orchard is good for life! Best to do both!
~GardensAll.com

So next time you’re planning your garden and deciding what to grow, consider choosing a perennial vegetable and other perennial plants in addition to your favorite annuals.

You might also enjoy this edible hedges article.

Let’s keep on growing!