As part of my extremely small gardening biz, I plan and care for gardens, with a special interest in edible and native plantings. In the winter months... oh who am I kidding... all the time, I obsess over client questions like 'what vegetables can be planted in the sand trap which is my front yard' or 'can I grow anything edible against the north wall of my house in the shade?'
Thankfully, the answer is surprisingly several and yes respectively, though I have to admit to making up these questions. Normally, people want to plant their edibles in sensible areas with at least 6 hours of sun and so on. However, I hate to think of any garden without something to nibble on so I ask myself these questions.
Drought tolerant, edible plants for northern sunny gardens
Generally the plants listed will require a well-drained soil in a sunny position. Not a complete list but here are some promising sounding ones:
Vegetables - perennial:
Prickly Pear Cactus - pads edible
Notes: A delicacy I have never tried but it is drought-tolerant. There are several types that are native to Canada and quite frost hardy.
Source: Gardens North
Nodding Onion (allium cernuum) - leaves, flowers, bulb
Notes: Several sources say 'very drought tolerant' so I look forwad to trying this out. It has a lovely pink flower and is supposed to taste good to boot.
Source: Gardens North, Edible Landscapes
Garlic Chives (allium tuberosum) - all plant
Notes: It is said to be fairly drought tolerant and does well in my non-irrigated sandy garden in the south side of my front yard. I have also heard of people growing it as a groundcover under trees - presumedly ones with open canopies. This is one tough plant so I don't doubt that it can take some punishment.
Source: Ask me, ask a friend. Someone you know has too much of this plant, various commercial sources including Ritchers who have an unusual pink flowered variety
Crambe (maritima & cordifolia) Sea Kale - young leaves, blanched shoots, young flowerbuds
Notes: Crambe maritima is seakale which should be hardy around here. It is going through its first winter in my garden so I'll let you know though it is mentioned in a gardening book from the Ottawa Valley. Crambe cordifolia may also be hardy around here and is known variously as flowering kale, giant kale or giant gypsophilia (baby's breath) according to Dave's Garden. Both of these plants are extremely attractive with large glaucous leaves and impressive sprays of flowers once they get going. They are drought tolerant because of their deep root systems. To ensure good root development, sow where you want it to grow.
Sources for seakale: La Societe des Plantes, Bountiful Gardens
Asparagus: new shoots
Notes: Sometimes listed as drought tolerant. This is because of their extensive moisture seeking root system. I would say that this is somewhat drought tolerant once established. It also prefers soil rich in organic matter.
Alfalfa, lucerne: growing tips, sprouted seeds
Notes: A nitrogen fixing plant with very deep roots that mine the subsoil. Compact salad plant or use for green manure to add a kick to your compost. It would make a pretty border plant and also attracts beneficials.
Sources: Ritchers, others
Jeruselum Articoke: tubers
Notes: Fantastic perennial food plant - pest resistant, drought resistant, will grow in light shade (gets about 4-6 hours in my yard and grows12 feet high with huge yields in droughted soil next to the western side of the house). I would ammend the soil with organic matter to keep up the fertility. The only caveats are that this plant stores sugars in the indigestible form of inulin which gives some people 'gas' and it does not store in a cellar well though I have developed a simple technique for storing which I'll write about another time. Maximillian perennial sunflower is a related species which according to the book Gaia's Garden produces smaller tubers and edible oil producing 'sunflower' seeds.
Sources: various, Mapple farm has the cultivar 'Volgo 2' which is less knobbly, plant small tubers from grocery store, contact me in the spring or fall for some.
Chinese Articoke: tubers
Notes: It is related to lamb's ear and is sometimes listed as drought-tolerant though it will produce better with more moisture. As they work like a ground cover, they might be nice to grow in and around other plants which would also shelter them a bit from drying winds.
Sources: Mapple farm
Notes: Really, most sedums are edible. Surprised? Me too, but there you go. I tasted S. telephium (like Autumn Joy) that were shade grown and they were quite nice, lemony. I have no idea what they would taste like if grown in full sun but it is worth a try and they look great in the garden too.
Yucca filamentosa & Y. glauca: flowering stem, flowers (bitter according to pfaf) and fruit
Notes: Too pretty to eat though I guess I could try the fruit. Very drought-tolerant.
Winecups or Poppy Mallow Callirhoe involucrata - roots and leaves
Notes: Have yet to try this one too, but the roots are supposed to be reminiscent of sweet potato. It's a mallow relative so the leaves are edible and are mucligenous according to pfaf like okra or some other cooked mallows. A true drought fighter, very pretty.
Sources: Cottage Gardener
Allium stellatum & Allium textile - whole plant I think
Notes: Prarie natives that can take dry soils. I don't know too much about these plants so you can check out Plants for a Future if you want more details.
Sources: Prairie Moon Nursery
Astragalus crassicarpus - plum milkvetch - seed pod
Notes: This plant gets an honourable mention from Gaia's garden about homescale permaculture. The plant looks like vetch but the seedpods look like itty bitty plums. It's also nitrogen fixing which means it would require less fertile soils. I've ordered seed so I'll let you know how it goes.
Sources: Prairie Moon Nursery
Psoralea esculenta - prairie turnip - taproot
Notes: When I was scanning Prairie Moon's seed list, I saw the name 'prairie turnip' and some googling revealed that it is considered very tasty. Yup, you guessed it. Seed will be arriving at my house for trial this spring. The plant looks like a small hairy lupin - another nitrogen fixer.
Straight forward wiki link
Sources: Prairie Moon Seeds
Eryngium maritimum - Sea Holly - blanched shoots, roots
Notes: Established plants are drought tolerant and they are also salt tolerant with an extensive root system that can be used to stabilize soil. I have never tried to eat this plant though I enjoy the blue flowered cultivars. I see this as a marginal vegetable as you unless you have a large population, digging up the roots would remove it. I am not sure of how many shoots you could blanch before you significantly lowered its growth potential.
Herbs - perennial:Sage - leaves, flowers*
Notes: Very hardy, very pretty and drought tolerant. A must for any garden.
Oregano - leaves, flowers
Notes: Golden leafed varieties are pretty. A distant relative of mint, need I say more? Yes, it will cover the ground in short order but it is delicious and hardy, as well as being pretty.
Thyme - leaves, flowers
Notes: From low growing mother-of-thyme to taller varigated varieties like lemon thyme (hardiness varies), these plants are lovely dainty, drought-tolerant perennials
Lavender - flowers, leaves (as a rosemary substitute, never tried this)
Notes: Used sparingly as a floral note in recipes or as potpourri. English lavendar (Lavandula angustifolia) is commonly used from what I read. Munstead is hardy in my garden.
Sources: various, Ritchers
German Chamomile - flowers for tea
Notes: The first year I put in a garden in a sandy ant ridden area of my yard, very few but the most drought hardy plants did well and included German Chamomile that flowered happily for most of the summer. Self-sows
Source: various, Ritchers
Orach - leaves
Notes: Though it is reputed to be drought tolerant, I hesitate when I write this as it is a salad green that prefers cooler weather like its relatives in the spinach family. If grown in a hot, dry spot, I imagine that it would bolt to seed fairly quickly depriving you of weeks of tasty greens and giving you a shorter but still attractive floral display.
Source: various, Wild Garden Seed
Amaranth - leaves, seeds
Notes: There are some beautiful cultivars with coloured leaves. Generally, the green leafed varieties are used as a vegetable and the white seeded form as a grain but all are edible. Self-sows.
Legumes: specifically chickpea, tepary bean, asparagus bean, peanuts and cowpea are drought tolerant but all prefer a long, hot growing season which northern gardens are often not blessed with. If you try these legumes, choose those that are selected for short seasons - often dwarf and small seeded - and cross your fingers. You can also space close together if yields are low to see if you get more seed per square foot that way. Heck, they may do well for you.
Sources: prarie garden seeds for tepary, salt spring seeds for chickpeas (winnifred's garbanzos did well for me, small, brown chickpea), valencia peanut is worth trying.
Wild roots - parsnips, wild carrot, chicories, burdock, dandelion
Notes: Many of these plants will grow in gravel if given half the chance and are often found in disturbed sites with poor soil. Though I know that some of them are listed as drought-tolerant such as burdock (cultivated varieties often known as Gobo), I imagine that drought would increase the strength of their flavour perhaps making them bitter. All of these are generally biennials except (some) chicory and dandelion that are perennials. Chicory and dandelion leaves are also edible. Again, leaves will be more tender if grown with moisture. I list these so you can try them if you like. If collecting wild, be careful not to confuse parsnip or wild carrot with some poisonness relatives.
Some more weeds: ox-eye daisy (edible leaves and flower buds), purslane (leaves, quite drought tolerant in my garden), common milkweed (pods, flowers, spring shoots edible, make sure you have the edible variety and check preparation of this plant), malva (young seed pods - cheeses, and leaves, look up your variriety), etc..
Misc. shrubs etc...
I am not going to go into any detail when it comes to the scaffolding of your garden, as lots of companies list drought tolerant, edible shrubs and trees, but here are some I bumped into while on my search: siberian pea shrub (lentil like seeds, invasive in some places), pinon nut, juniper (berries edible), saltbush (leaves, atriplex canescens: grows in Saskatchewan so may be hardy), seabuckthorn (berries)
Southern vegetables, northern gardens
When looking for traditional vegetables that are drought tolerant, note that many are bred for conditions of southern gardens which are also very hot so they won't necessarily do well in areas with cooler, shorter seasons. Of course, there will be seed adapted to short season, cold winter living such as plants that grow in the Canadian prairies but they will also expect a bit of sun. Obviously, what's adapted to your locale will work best.
Cool season crops such as cabbages or peas usually need a bit more water so though they are often good for areas with shorter seasons or less sun input but not drought.
Low watering veggies
If you plan on limiting supplemental watering in your vegetable patch, space your plants farther apart than suggested to give the roots more space to search for water. Plant cool season crops or crops that prefer a good watering in sunken beds that gather water. This will also create a cooler microclimate. I find that dotting these plants near the 'trench' cut edge of my garden border improves their growth. Mulching with flat stones will also help keep the ground cooler and wetter while absorbing heat to be released at night thereby moderating the microclimate. Generally mulching will help maintain soil moisture. If you use organic matter as mulch, it will break down and mix with the soil improving its texture and moisture retention.
If you live in an area that experiences frequent drought, then plant your veggie patch in place sheltered from the prevailing winds (plant a wind break if need be - jeruselum artichoke can act as a herbaceous one though it is invasive so best planted 'out of the way' or somewhere contained). You can also contour your beds to direct water flow and to prevent it from escaping. A pond or rainbarrels will help collect extra water for irrigation in dry times. You can also recycle your greywater.
Use drip irrigation to make sure the water goes just where it is needed. Deeper, infrequent watering will help edibles to develop deeper root systems that will further help them tolerate drought. Morning watering is prefered as it lowers evaporation but also allows plant leaves to dry out keeping foliar diseases in check.
And finally, allow plants that root on the stems like squash and tomatoes to sprawl on the ground further increasing their ability to mine water.
Now it is time for me to hit the drawing table to produce some mock plans for a dry front yard edible patch. Who knows, next year someone might ask for it.
Search terms that might help: xeric / dryland / dry farming / drought-tolerant vegetables / edibles / herbs. Let me know if you find something else!
* Some people will react to the pollen in edible flowers so use cautiously.