Drought Tolerant Plants

Photos by the Neilsons

Plants can be found in a great diversity of habitats and some pretty extreme environmental conditions. In order to persevere, plants have evolved mechanisms to cope with stresses. In the case of prairie or desert plants, one of their biggest challenges is surviving periods of drought. 

Plants can better survive drought by increasing their ability to access water, decreasing the amount of water they lose through everyday processes, and/or improving their ability to store water. Many prairie plants have developed extensive root systems. In fact, for the average prairie plant, only about one third of its plant matter consists of leaves, stems, and flowers – the remainder is roots. Compass plant and blazing star have roots that reach 3 to 4.5 metres into the ground, allowing them access to moisture far below the soil surface. Some other plants, such as certain coneflowers, develop fibrous root systems that absorb water like a sponge.

The development of narrow, vertical leaves, such as those of yuccas, minimizes the leaf surface exposed to sunlight, thereby decreasing the amount of water lost through evaporation. Compass plant has the unique ability to orient its basal leaves in a north-south direction to serve this same purpose. Dense hairs or bristles on stems and leaves, such as those found on butterflyweed, yucca, and prairie star, or a thicker leaf Prairie Coneflower surface, such as that found in bearberry, are other ways for plants to minimize water loss.

Cacti are probably the plants most often associated with drought conditions. There are several species of cacti native to Canada. One of the ways these plants survive drought is through their very efficient water storage capabilities.

The species of plants you can find surviving in drought situations are as diverse as the methods they have for adapting to these conditions. The following plants are just a few examples of drought tolerant plants.

Yucca glauca

Range: seAB 
Description: Soapweed has stiff, narrow, grey-green leaves that reach a height of one meter. In the summer, it has spires of creamy white flowers. 
Habitat: Soapweed is found in dry plains and sandhills. It likes dry, well-drained soil in full sun 
Wildlife: Yuccas provide nectar and pollen for hummingbirds, moths, and other pollinators. They are the larval food plant for the yucca moth. 

Opuntia fragilis

Range: BC - ON
Description: Brittle prickly-pear is so named because its pads are easily broken off. It is a mat-forming cactus with sharp, barbed spines and large yellow flowers that appear in early to mid-summer. 
Habitat: Brittle prickly-pear is found in dry prairies, sandhills, and rocky areas. It likes dry, well-drained, sandy soil in full sun
Wildlife: Prickly-pears provide nectar and pollen for bees and other insects. Small mammals and insects feed on the fruit.

Arctostaphylos uva-ursi

Range: YK, NW, BC to PE
Description: Bearberry is a ground cover, 8-20 cm in height, with glossy, dark green leaves. It has small pink or white flowers in spring, which are followed by large red berries.
Habitat: Bearberry is found in dry woods and rocky areas. It likes dry, well-drained, acidic soil in sun or partial shade.
Wildlife: Bearberry is an early nectar source for bees and other pollinators. Its berries provide food for mammals and birds.

Oenothera biennis

Range:BC to PE
Description: Evening primrose varies in height from 30 – 150 cm with large yellow flowers that open in the evening. It blooms from summer through to the fall. 
Habitat: This flower can be found in fields, clearings, and roadsides. It likes dry to moist soil in full sun.
Wildlife: Evening primrose provides pollen and nectar for bees, hummingbirds, and other pollinators, but is especially important for moths.

Ratibida columnifera

Range: seBC, sAB, SK, sMB
Description: Prairie coneflower is 30-120 cm in height. In summer it sports yellow flowers with very long, green to brown, central cones.
Habitat: Prairie coneflower can be found in plains, prairies, ravines, and hillsides. It likes dry, well-drained soil in full sun.
Wildlife: Prairie coneflower provides pollen and nectar for bees, butterflies, moths, and other pollinators. It is also a great seed source for birds and mammals.

Asclepias tuberosa

Range: ON, swQC
Description: Butterflyweed has brilliant orange flowers in summer. With hairy and leafy stems it reaches a height of 60 – 90 cm. 
Habitat: Butterflyweed can be found in dry, relatively open areas. It likes dry, well-drained soil in sun to partial shade.
Wildlife: Butterflyweed is an excellent source of nectar for bees, butterflies, hummingbirds, moths, and other pollinators. Milkweeds are the larval food plant for the monarch butterfly.

Linum perenne lewisii

Range:YK, NW, BC – QC 
Description: In summer, the delicate stems of blue flax are covered with a profusion of vibrant, blue flowers that appear to float in the air. It reaches a height of 30 – 60 cm. 
Habitat: Blue flax is found in prairies and alpine ridges. It likes dry, well-drained soil in full sun.
Wildlife: Blue flax attracts bees and other pollinators and is a butterfly larval food plant. 

Geum triflorum

Range: NW, BC-ON 
Description: Prairie smoke reaches a height of 30 cm, has a rosette of leaves at the base of its stem, and sports small pinkish-red flowers in spring. Its most interesting feature is its upright, feathery, seed heads.
Habitat: Prairie smoke can be found in dry prairies and alvars. It likes dry, well-drained soil in full sun.
Wildlife: Prairie smoke is an important early food source for small bees.

Liatris punctata

Range:AB-MB
Description: Dotted blazing star reaches a height of 30 – 60 cm with spikes of purple flowers covering the top 10 cm of the stem. 
Habitat: Dotted blazing star is found in dry prairies and plains. It likes dry soil in full sun.
Wildlife: Blazing stars are an important nectar source for butterflies. It also attracts hummingbirds, other insect pollinators, and provides seeds for birds.

Silphium laciniatum

Range: sON
Description: This towering plant reaches heights of 1-3 m. It has deeply lobed leaves and is covered in large, yellow flowers in summer and fall.
Habitat: Compass plant can be found in prairies and other open areas. It likes dry to moist soil in full sun.
Wildlife: Compass plant provides pollen and nectar for bees, butterflies, and other pollinators. It is also a good source of seed for birds.