This is the third and final installment in our water wise gardening series. It's time to get plant specific, so today we will look at the precise characteristics that allow a plant to tolerate low water resources. Then we will go through all the trees, shrubs, perennials, and annuals that are drought tolerant and hardy for the Calgary area. I'll bet there are a lot more than you thought! Unsurprisingly, many of the plants that grow well here have to be drought tolerant to survive our limited moisture environment.
Sorry this one took awhile, but there were a lot of photos to go through for this article! All photos are my own, unless noted otherwise.
Water Until Well Established
No matter how drought tolerant your plants are, there is one portion of their lives that they absolutely will need supplementary water and that is when they are first planted. In order to get those roots established and growing they will need more water than Mother Nature can provide. In particular, the first growing season requires extra care for your plants that are perennials (trees and shrubs included). For the first 3 weeks or so, water once a week at least 1". A soaker hose set out for 1 hour each week works perfectly. After the first three weeks, water during hot weather only. After that, you should be good. If you notice browning or wilting after that point, water until soil is moist to a depth of 4-8". Drought tolerant annuals will need a very good watering upon planting and supplemental watering for the first couple of weeks. After that, they should only need water during long periods of drought. If annuals are planted in a container or basket they will always need more water than those planted in the ground. The amount will depend on the size of the container, type of soil and sun exposure.
Drought Tolerant Strategies
Drought tolerant plants will be best able to deal with water stress. So how do they actually do it? Learning that will help us choose the best plants for our unique situations, determine if a random plant we come across is drought tolerant, and maybe even help those plants get by with even less water.
Succulent leaves store water to be used in times when the wet stuff is scarce.
Thick, waxy leaf surfaces (the cuticle) prevent evaporation from tissues.
Extensive root systems, either along the surface for fast absorption or a tap root to mine water deep down in the soil.
Small and decreased number of leaves ensure less transpiration (release of moisture from the leaves through special pores called stomata).
Hairy leaves reduce evaporation due to wind by slowing air movement at the leaf surface.
Silver or grey coloured foliage and stems reflect light and therefore reduce heat gain.
Plant dormancy during hot and/or dry times.
So let's take a look at some of the trees, shrubs, perennials and annuals that are drought tolerant and perfect for our Zone 3 chinook region. See if you can recognize any of the above strategies! I have listed those species that are super drought tolerant with just a quick description. I have also listed some honorable mentions that are fairly drought tolerant (but not quite as much as the others). These may need some additional moisture during extreme heat and drought conditions.
Drought Tolerant Trees and Shrubs
There are a number of great options for drought tolerant trees and shrubs. Many of them were used as shelter belt plants on the prairies and therefore have a suckering habit. This is when the plant sends up shoots from the root area. This is fantastic for hedges or if you want your plant to spread, but can be annoying if you don't. Look for varieties that specify that they are non-suckering or ask at your local greenhouse for assistance with variety selection. Many of them are also berry producing, some even good for us to eat. Multi-purpose! And a few are even nitrogen fixing. Bonus points if you can find find one that is both (looking at you buffaloberry!).
Caragana (Caragana)
Caragana, especially the common variety, has gotten a bad rap lately. Many people call it invasive, but really, it is just a really good grower, especially in tough conditions. This guy is crazy hardy (zone 1!) and very drought tolerant, making it a super resilient. It also suckers, a lot. This can be taken advantage of if it is used as a hedge. It is especially useful as a hedge to keep out wildlife, as it can be quite large and has some decent spines on its branches. One of the best things about Caragana is that it is a nitrogen fixer, adding nutrients back into the soil for itself, and surrounding plants. Check out some other varieties of Caragana that are much more well behaved than the common type:
Sutherland Caragana - upright, narrow columnar tree with a very architectural look
Green Spires Caragana - taller, somewhat narrow shrub great for screening
Walker Weeping Caragana - short weeping tree that is great as a focal point
Globe Caragana - small (3'x3'), very compact and tidy looking shrub
Pygmy Caragana - slightly larger than Globe and a more free-spirited look.
Cotoneaster (Cotoneaster)
This is the hedge that you see absolutely everywhere and for good reason. It is easily trimmed into tidy shapes due to its fine foliage and quick growth. You can also grow it as a free form shrub; it has a very nice shape all on its own. It also has fantastic fall foliage and berries that are not edible for us, but are great for wildlife (birds and deer especially). Note that it can be susceptible to oystershell scale. I have fond memories of squishing the blossoms and eating the "honey" when I was a child. Maybe make sure you do this only when you know pesticides haven't been used.
Russian Olive (Elaeagnus angustifolia)
A smallish tree with stunning true silver foliage all season long. In spring, small yellow flowers make themselves known with a strong lemony scent. Russian olive is a nitrogen fixer and has some significant thorns on it as well. This makes it fantastic as a barrier plant to keep out browsers. Do not plant this one in riparian (stream or lake side) areas, as it can become invasive when given that much moisture.
Wolf Willow/Silverberry (Elaeagnus commutata)
If you are ever taking a hike in Southern Alberta in the spring and you smell an almost overwhelming fragrance, you've found wolf willow. This is a super hardy, smaller shrub with narrow leaves that are a fuzzy silver. Small, silver, dry berries are produced later in the summer that are technically edible but not overly tasty. The pits were often used by Aboriginal peoples in jewelry and other decorations. Make sure you are comfortable with its suckering habit because it will definitely sucker. Like its relative, the Russian olive, this guy is also a nitrogen fixer. No spines though.
Purple Leafed Sand Cherry (Prunus x cisterna)
As you can tell from the name, this guy has serious colour appeal all season long! It has burgundy foliage which is beautifully contrasted by light pink flowers in mid spring. Very useful as an accent in the garden. Berries are edible, but need a fair amount of sugar (think jellies) to make them tasty. Remove the pits before processing as they are not so edible. This shrub will spread, but not all crazy like a wolf willow.
Russian Almond (Prunus tenella)
If you need early spring flowers in shrub form, this is it! Fragrant pink flowers blanket this shrub before the leaves even unfurl. Summer it is kind of plain and in fall the leaves turn a nice yellow. Occasionally fuzzy, almond shaped fruits will appear. Once again, this guy suckers, so know before you grow!
Silver Buffaloberry (Shepherdia argentea)
This is the shrub to get if you have really poor soil. It is very hardy (zone 2) and will tolerate both dry and alkaline soils with little nutrition. It is a nitrogen fixer so it will improve those poor soils over time too. It has narrow silver leaves and produces a ton of small red berries, making it quite showy. You will need both a male and a female shrub for berry production (or a shrub with both grafted onto one rootstock). The berries are edible to people (good in jelly), but I often see this shrub used as a distraction for berry-loving birds. They prefer buffaloberry over the berries people tend to love more. This is a fairly large shrub with thorns and a medium to high suckering habit.
Lilac (Syringa)
Who doesn't love the smell of lilacs? They are fast growing, super hardy and quite showy with their large clusters of blooms. Many varieties can sucker tremendously (which is great if you want a hedge, but not so much if you don't), so do a bit of research first into different varieties if this is something you are not okay with. Wait to prune these guys until after they have finished blooming in late spring or summer. If you prune in late winter or early spring (as you do with many other trees and shrubs) you will be removing future blooms.
Honorable Mentions:
Ash (Fraxinus)
Subalpine fir (Abies lasiocarpa)
Amur maple (Acer ginnala)
Manitoba Maple/Box Elder (Acer negundo)
Saskatoon (Amelanchier alnifolia)
Kinnikinnick (Arctostaphylos uva-ursi)
Hawthorn (Crataegus)
Sea buckthorn (Hippophae rhamnoides)
Juniper (Juniperus)
Siberian Larch (Larix siberica)
Honeysuckle (Lornicera)
Spruce:
Black Hills spruce (Picea glauca var. densata)
Colorado spruce (Picea pungens)
Pine:
Jack pine (Pinus banksiana)
Swiss stone pine (Pinus cembra)
Lodgepole pine (Pinus contorta var. latifolia)
Limber pine (Pinus flexilis)
Rocky mountain yellow pine (Pinus ponderosa var. scopulorum)
Scots pine (Pinus sylvestris)
Cherry prinsepia (Prinsepia sinensis)
Plums and cherries:
Mongolian cherry (Prunus fruticosa)
Pincherry (Prunus pensylvanica)
Double flowering plum (Prunus triloba ‘Multiplex’)
Chokecherry (Prunus virginiana var. melanocarpa)
Bur oak (Quercus macrocarpa)
Sumac (Rhus)
Golden currant (Ribes aureum)
Rose:
Prickly rose (Rosa acicularis)
Prairie rose (Rosa arkansana)
Altai rose (Rosa spinosissima)
‘Hazeldean’ rose
Red-leafed rose (Rosa glauca)
European red elder (Sambucus racemosa)
Ural false spirea (Sorbaria sorbifolia)
Western snowberry (Symphoricarpos occidentalis)
Wayfaring tree (Viburnum lantana)
Nannyberry (Viburnum lentago)
Drought Tolerant Perennials
Unsurprisingly, many of the perennials available in garden centres here are drought tolerant. Ones that tend to do well in our climate often have to be! Many of the perennials also come in multiple varieties. Often the fancier varieties tend to be less hardy than the standard or more simple varieties. Always check the tags for the zone rating. And remember, the more simple and closer looking to the native species, the better for our beneficial insects. Look for all those traits of drought tolerant plants that are mentioned above and scroll through and find ones that strike your fancy.
Yarrow (Achillea)
Many people know this one as a weed in their garden. There is a weedy yarrow that is common here, but most of the yarrow you buy in a garden centre is completely different in growth habit. The flowers come in a multitude of colours that are attractive to bees, butterflies and many beneficial predatory insects. Not only that, the deep roots of yarrow are nutrient accumulators of both phosphorous and copper. Tough, useful and pretty all in one package.
Thrift (Armeria)
A compact plant with a spikey, mounding shape. Pink drumstick shaped flowers shoot up from the grassy tuft of foliage. This one is perfect for rock and alpine gardens where its petite form can be best appreciated. Deadhead often to keep the flower show going all summer long.
Silver Mound (Artemesia)
I like to use this plant as a repeating element throughout my garden to tie it all together. It is compact and tidy, forming a perfect mounding ball of fine silver foliage that stays throughout the entire growing season. It is a member of the sage family and has the most fantastic aromatic foliage ever! Seriously, next time you see it at the garden centre or in a neighbour's yard, give it a little rub and take a sniff. If anyone looks at you funny, tell them to do the same and they will understand. And try to plant it somewhere where you will occasionally rub it in passing to get that scent in your own garden.
Perennial Alyssum (Aurinia saxatilis)
Also known as golden alyssum or basket of gold, this is an easy to grow groundcover that will quickly enrobe any bare spots with a carpet of golden yellow, long blooming flowers. The bright flowers contrast nicely with the silver-grey foliage. It is beautiful draping over raised bed edges and rocks. This one is fairly well known and you can see great examples in many neighbourhoods. Just look for the large mass of golden flowers. Great for hot, sunny spots.
Blue False Indigo (Baptista australis)
I honestly don't know why more people don't grow this fabulous plant. It has stunning pea-like blue-purple flowers on quite tall stems. And best of all, it is a nitrogen fixer, so it is beneficial to all the plants surrounding it. False Indigo takes a couple years to really get going, but once it does, it is pretty much maintenance free. Don't be tempted to move this one around, as it resents being disturbed. Just give it some time. Even though it is taller (up to 3-4 feet) it is a sturdy guy; no staking needed. Butterflies love this plant!
Snow In Summer (Cerastium tomentasum)
This is an easy to grow evergreen groundcover with striking silver grey foliage and masses of white flowers for the majority of the summer. It is crazy hardy (Zone 1!) and a fast spreader so plant it in tough conditions (poor soil, lots of heat and drought); it can take over if treated too well. Not for the rock garden unless you want only this plant. It is much too aggressive. Shear it back after blooming to keep it tidy looking.
Lily of the Valley (Convallaria majalis)
This is the queen of dry shade. It's an aggressive spreader and is quite poisonous, so be aware where you plant it and who may try to eat it. It is perfect for under trees or decks, just be sure you have a deep edging or border to keep it contained. Perfect for really difficult locations. Don't let me discourage you too much from this plant, the flowers smell absolutely divine! So much so, it is used in many perfumes. You can also find a pink flowering form in garden centres if you look hard.
Dianthus (Dianthus)
There are many types of perennial Dianthus available in garden centres today: cottage pinks (also known as garden pinks), maiden pinks, cheddar pinks, sweet Williams, and some of the newer hardy carnations (although these tend to be far less hardy here than all the others). Sweet Williams are a tough plant that have been around for ages (one of those old fashioned ones). That should tell you that they are easy to grow and very resilient! They are much taller than the others (up to 2 feet) and are short lived, so let them self seed. Maiden pinks and cottage pinks tend to be more of a low ground cover, flowering in late spring and sporadically throughout the summer. Cheddar pinks tend to form more of a spiky mound and include my very favourite variety 'Firewitch' which has silver-grey foliage and neon pink flowers. All have the typical nutmeg-like scent of carnations and are covered with blossoms. All of them also have edible flowers. Just be sure to remove the calyx before eating, it is quite bitter. Most varieties are evergreen, but check your tags to be sure.
Coneflower (Echinacea)
These have daisy type flowers in a multitude of colours. Be careful which varieties you choose, as there are many available at garden centres that are zone 4 and above. They are usually the "fancy pants" ones. Look for simple flowers like 'Magnus', "Prairie Splendor', 'White Swan', 'Cheyenne Spirit', 'Ruby Star', or any of the 'Pow Wow' varieties. The hardiest of all is the standard species Purple Coneflower (Echinacea purpurea) with no variety name pictured at right. Flowers are long blooming, especially if kept dead-headed. They are also loved by bees and especially butterflies.
Sea holly (Eryngium)
Some people aren't too thrilled with a thistle looking plant in their gardens, but this one may just change their minds. It has fabulous blue coloured flowers and is absolutely striking! Sea hollies appreciate hot dry sites and they don't mind our alkaline soils at all. They are a favourite for cut and dried flowers. I prefer the Blue Sea Holly (Eryngium planum) especially the variety 'Blue Cap'.
Blanket Flower (Gaillardia x grandiflora)
These grow wild here so you know they are going to be hardy (zone 2 actually)! These are one of the longest blooming perennials in the garden. In fact they are often short lived (usually 2-4 years) because they bloom themselves to death by using up all their energy on flowering. Enjoy their sacrifice and just purchase new ones as needed. Flowers tend to be multi-coloured in shades or yellow, orange, red and brown. Like many perennials here, many of the newer, fancier ones tend to be less hardy, so always double check the zone rating on the back of the tag before purchasing.
Cranesbill Geranium (Geranium)
Perennial geraniums put on a show of flowers all summer long. Cut back the flowers and foliage hard after blooming is done to keep them looking neat and tidy for the rest of the season. Many varieties also have fantastic smelling foliage that turns vivid red in the fall too. You do need to watch though, as not all varieties are drought tolerant. Check out the ones listed below.
Bloody cranesbill (Geranium sanguineum)
‘Johnson’s Blue’
Bigroot geranium (Geranium macrorrhizum)
Rock Rose (Helianthemum)
A member of the sunflower family, you can tell from the name that this beauty prefers hot, dry, and rocky locations. Wild rose like flowers top evergreen silver-grey foliage that slowly spread into a mat. These are very versatile plants that do well in rock gardens and borders alike; great for draping over edges. Showy flowers vary from pink to red to orange to white to yellow. Just make sure they have good drainage.
Blue Oat Grass (Helictotrichon sempervirens)
Similar to Blue Fescue but on a much larger scale (and far more reliable). It is a grass with stunning steel blue foliage that forms a large spiky ball. Tan seed heads extend upwards and add to the impact and movement of this plant. One of the absolute best grasses for our growing region and one of my favourites too. If you want more plants, it is easily divided in spring. Don't confuse this with Bulbous Oat Grass, which is a whole different thing.
Daylily (Hemerocallis)
You can absolutely never go wrong with daylilies. They will grow pretty much anywhere: sun, shade, wet, dry, you name it. 'Stella D'Oro' is a smaller, yellow variety that has been around forever and is super dependable, but there are daylilies available in absolutely every colour of the rainbow, including white and black (which is really dark purple). Some are shorter (around 12 to 24") and some get up to 3 feet or so. You definitely need at least one in your garden. Look for varieties that state they are repeat blooming on the tag for an even longer season of blooms.
Candytuft (Iberis sempervirens)
A spring blooming evergreen groundcover, candytuft has brilliant white blooms that completely cover the plant. Cut back the plants by at least half after blooming and you will get a good flush of foliage to last you through the season. These guys are not suitable for dividing, as the entire mat or bushy growth is usually born from a single woody stem.
Deadnettle (Lamium maculatum)
A fairly fast growing groundcover for dry shade, Lamium is dead easy to grow. The leaves are presented in various combinations of green and silver on the different varieties (although there is one variety that has yellow leaves). Flowers are pink, purple or white. Lamiastrum (False Lamium), with pointier leaves and yellow flowers, use to be included in this group and may be rejoining it. All of these are fast growers that can be easily propagated by just digging up a clump and replanting. If your patch starts to look raggedy, just give it a hard cutting back. I have even used a mower on mine to great effect.
Lavender (Lavendula augustifolia)
An evergreen perennial that often gets some winter dieback in our climate, lavender cannot be beat for scent. Look for English lavender, which is the one that is perennial here. Munstead and Hidcote are the most available varieties. French and Spanish lavender are not at all hardy here, although often sold as annuals or indoor tropical plants. Check what you are buying before you assume it will overwinter. Hint: if it is in a topiary form, it is definitely not hardy here. Butterflies will flock to the light purple blooms. A good layer of mulch will help to reduce winter dieback.
Sea Lavendar/Statice (Limonium latifolium)
For those of you missing the old fashioned Baby's Breath (it has recently been classified as an invasive weed), here is your replacement. Tiny sprays of lavender blue flowers are presented in a spray high above a bushy rosette of green foliage. This is the ultimate filler for cut flower arrangements and can also be dried for more permanent displays.
Prickly Pear Cactus (Opuntia polyacantha)
The flowers on cactus never cease to amaze me; they are absolutely stunning! When I was young (and before we knew better), we used to dig these guys out of the ditch on our drives through Saskatchewan and bring them home to plant in our garden. No need for that now, they can often be found in local garden centres. Ensure you plant these in a spot that the thorns will not surprise anyone. They are not fun to remove from kids or dogs.
Japanese Spurge (Pachysandra terminilus)
Unrelated to the well-known cushion spurge, Japanese Spurge is a hardy groundcover for those part shade to shady spots. It will take a couple years to get going, but once it does, it fills in quickly and densely. Plant fairly close together to get it nice and full looking. The leaves are evergreen and extremely glossy. There is also a variegated variety that is quite stunning in large mats. Small white flowers are born on the ends of each shoot in spring.
Peony (Paeonia)
Everyone knows and loves peonies, right? Huge, beautiful blossoms that smell amazing bloom on plants that are super hardy and are extremely long lived. These guys have often been found on old homesteads and farms that have been abandoned, still going strong after years of neglect (and no supplemental watering)! Typical garden peonies come in whites, pinks and reds with both single and double flowering varieties. Specialty peonies like Itoh and Tree peonies (many more colours like yellow and orange) and Japanese Fernleaf peonies (stunning foliage) are also available in many garden centres, but can be very pricey. They are just as hardy as regular peonies, just very hard to propagate (hence the hefty price tag). The trick to peonies, is to ensure they are planted at the exact same level as they were in the pot. Too deep and you will have wonderful foliage and zero blooms.
Perennial Sage (Salvia numerosa, Salvia sylestris)
A standard in the perennial garden, salvia is the epitome of easy care. Bees and hummingbirds are attracted to this plant, while grazers tend to leave it alone, probably due to its strong smell (it is a sage after all). Leaves are olive green to slightly grey. Flowers are long blooming and come in mostly purples, although there are now some pink and white varieties available. Tall spikes of blooms make great cut flowers. Deadhead after blooms are done and you may get another flush of flowers in late summer.
Stonecrop (Sedum)
This is a huge group of succulent leaved plants! They can be divided into upright sedums and groundcover sedums. Both groups are very drought tolerant. Upright sedums bloom in late summer and into fall and are fantastic at attracting pollinators. Bees love them! The variety 'Autumn Joy' has been around the longest and is consistently a good grower in our climate, but there are many new varieties with various flower colours and foliage colours too. The groundcover sedums are seriously diverse. The foliage ranges from pine-needle like to tiny spheres to lobed leaves. And the colours of both foliage and flowers are infinite really. Your only option is to go to a garden centre and peruse the large selection, finding one that strikes your particular fancy.
L to R: Dragons Blood Stonecrop, Russian Stonecrop, Autumn Joy Sedum, Matrona Sedum
Lamb Ears (Stachys byzantina)
The common name of this guy comes from the super soft fuzz on the silver leaves of this plant. Kids absolutely adore them! It is great at attracting pollinators and tends to not get nibbled on by rabbits and deer. Pink flowers are borne on spikes in early summer. Be aware that this is a spreader though (it's in the same family as mint to give you an indication of its spreadiness). It can travel via the roots underground and can also self seed. Aggressively pull out any unwanted areas yearly to keep it under control. And don't forget to deadhead it.
Thyme (Thymus)
Thyme is the standard between-stepping-stones plant. It is crazy hardy and can take lots of abuse from walking on. There are many varieties that grow well here, some of them super short and dense, such as 'Elfin' and some of them a bit taller (up to 4" or so). 'Doone Valley' is my absolute favourite for it amazing lemon scent, but I also plant common thyme (Thymus vulgaris) for culinary purposes even though it is less hardy. Oh, and I also have the 'Elfin' variety (Thymus praecox) and a couple other full blooming ones. There are just so many to choose from! Can you tell I love thyme?
Periwinkle (Vinca minor)
Another groundcover, this one has a bit more height to it and is not great for walking on. It is however, fantastic for shady dry areas like under evergreen trees. Glossy leaves and periwinkle blue flowers crawl over themselves to form a thick mat. This is a fast grower. The stems will root wherever they come in contact with the soil. This makes them very easy to propagate, just dig up a rooted section. Cut back or mow to increase the density as needed.
Hops (Humulus lupulus)
Need a vining plant? Crazy hot and dry area? Hops is the answer! Ensure you have a strong trellis as this guy is a fast grower. It will easily twine around anything it finds. It has good herbivore resistance too, as the stems and leaves have pokey hairs on them. The plant dies back to the ground each fall and emerges again each spring. You can easily find the standard variety and often golden varieties in garden centres. If you are a home brewer, look for hops specific for beer making like 'Centennial', 'Golding', 'Cascade' and 'Sterling'. The flower heads, or cones, can be quite aromatic in many of these varieties. Ensure you have female varieties for beer making, as only female plants produce the cones or flowers.
Virginia Creeper (Parthenocissus quinquefolia)
Probably the most vigorous vine available in our zone, Virginia Creeper can get to huge sizes. Like cover the side of an entire house huge. If you need full coverage, this is it. This guy is often bothered by leafhoppers. They won't do much damage, but they can be annoying to sit close to, so don't plant this right beside your seating or dining areas. The fall colours of this vine make it worth planting in itself.
Engleman ivy (Parthenocissus quinquefolia 'Englemannii') is a variety of Virginia creeper with slightly smaller leaves and better disease resistance. It also has amazing fall colour. This will not only twine around a trellis, it will also physically adhere to it. So, if you ever need to remove the vine (to paint or repair what it is climbing on), choose Virginia Creeper instead of Engelman Ivy.
Honorable Mentions
Hollyhock (biennial) (Alcea)
Snowdrop anemone (Anemone sylvestris)
Pussytoes (Antennaria)
Rockcress (Arabis caucasica)
Swamp milkweed (Asclepias incarnata)
Bergenia/Elephant ears (Bergenia cardifolia)
Globe centaurea (Centaurea macrocephala)
Bachelor buttons (Centaurea montana)
Barrenwort (Epimedium)
Globe thistle (Echinops ritro)
Fleabane daisy (Erigeron speciosus)
Pincushion cactus (Esobaria vivipara var. vivipara)
Blue Fescue (Festuca glauca)
Avens/Prairie smoke (Geum triflorum)
Creeping baby’s breath (Gypsophilia repens)
False sunflower (Heliopsis helianthoides)
Edelweiss (Leontopodium alpinum)
Blue lyme grass (Leymus arenarius)
Perennial flax (Linum perenne)
Birdsfoot trefoil (Lotus corniculatus ‘Plenus’)
Catmint (Nepeta)
Evening primrose (Oenothera missouriensis/macrocarpa)
Oriental poppy (Papaver orientale)
Beardtongue (Penstemon)
Russian sage (Perovskia atriplicifolia)
Ribbon grass (Phalaris arundinacea var. picta)
Moss phlox (Phlox subulata)
Cinquefoil (Potentilla)
Pasqaue flower/prairie crocus (Pulsatilla vulgaris)
Pincushion flower (Scabiosa caucasica)
Hens and chicks (Semipervivum)
Goldenrod (Solidago)
Big betony (Stachys macrantha)
Wooly speedwell (Veronica incana)
Whitley’s speedwell (Veronica whitleyi)
Culver’s root (Veronicastrum virginicum)
Canada violet (Viola canadensis)
Barren strawberry (Waldsteinia ternata)
Yucca/soapweed (Yucca glauca)
Golden clematis (Clematis tangutica)
Allium
Asiatic lily (Lillium)
Tulip
Tulipa tarda
Tulipa urumiensis
Drought Tolerant Annuals
Annuals can be planted right into our in-ground beds or into containers, including hanging baskets. Because containers dry out so quickly, especially in warm weather, drought tolerant options become even more important. Who wants to spend their entire summer constantly watering? Not me!
Love Lies Bleeding (Amaranthus)
Fantastic name, right? Also called Tassel flower or Chenille Plant for the long, soft and trailing flowers. The entire amaranth family not only has stunning flowers, but all parts of the plant are also edible. The seeds (considered a superfood) are a well known grain in South America and the leaves (similar to spinach in flavour and texture) are full of nutrients. Plants can vary in size from small and suitable for containers to 10 foot giants.
Cupid's Dart (Catananche caerulea)
Used as a component of love potions in medieval Europe, this frilly edged bloom comes in common blue, white or bicolour versions (blue and white together). It is also fantastic as a dried flower.
Celosia (Celosisa)
Definitely the weirdest of all annuals, Celosia has extremely colourful odd shaped flowers. It is found in three major forms: crested Celosia crestata (which looks like brain coral or a rooster comb), feather Celosia plumosa (fluffy plumes) , and wheat types Celosia spicata (stiff spikes) . All thrive in hot dry areas.
Photo by Pixaby
Dusty Miller (Centaurea cineraria and Tanacetum ptarmiciflorum)
A standard in many borders and baskets, the lobed sliver foliage of this bedding plant is the perfect contrasting accompaniment to any flowering plant. Both species have striking silver fuzzy foliage. They differ in the fineness of their foliage with Centaurea being more lobed and Tanacetum being more ferny in texture. Plant them with any bright coloured flowers or within an all white arrangement for a real show stopper.
Godetia (Clarkia amoena, C. elegans, C. pulchella)
The flowers of this beauty remind me of an extra satiny rose. It is available in various pinks, whites, reds and lilacs. Sow seeds for Clarkia directly in the garden, as they dislike being transplanted. They enjoy cool summers and sun to partial shade. No fertilizer for these guys or you will get fabulous foliage and few flowers.
Spider flower (Cleome hasselerana, C. lutea)
Cleome is a very tall dramatic plant with strong scented flowers, making it best for the back of the border. Flowers are pink, lavendar, white or yellow with long prominent stamens that give it its common name Spider Flower. Decorative seed pods form along the stem as new flowers develop at the top of the stalk.
Cosmos (Cosmos bipinnatus)
A classic flower in the garden, Cosmos are tall stately plants, usually 2 to 3 feet tall, with fine ferny foliage that gives it an ethereal look. Flowers are daisy type with serrated petal edges in pinks, whites and reds. It loves hot, dry locations with poor soils.
Kenilworth Ivy/Pennywort (Cymbalaria muralis)
One of my absolute favourites, this fine textured creeping annual is perfect for trailing out of baskets or over rocky edges in part shade to sunny spots. It has tiny pale lilac flowers that make it extra dainty. It often overwinters in our climate. I particularly love it with tuberous begonias.
Angel's Trumpet (Datura)
Absolutely beyond showy, the flowers of this large plant (it's a tree in more tropical climates) are massive trumpet shaped white, yellow or lilac coloured attention getters. Often grown as a conservatory plant, it is easily brought inside for the winter months. Ensure you give it a sizable pot if you are going to keep it year round. Datura is very poisonous, so be extremely careful if you have young children or pets.
Cape Marigold (Dimorphotheca sinuata)
Daisy like flowers of white, yellow, orange or rose abound on this plant with the petal undersides being blue or lavender. Like many other drought tolerant daisies, these guys close up at night and on cloudy days.
Viper's Blugloss (Echium lycopsis)
Mounds of cup-shaped flowers in blue, purple, rose or white adorn stems of blue-grey bristly leaves. No fertilizer for this one either, if you want lots of blooms. The viper reference in the common name is in reference to the snake head shaped seeds.
Annual Blanket Flower (Gaillardia pulchella picta)
Gaillardia is available in both annual and perennial versions. The annuals can be single or double flowering in yellows, oranges, reds and whites, with many bicolour types as well. They need full sun and withstand high heat and drought easily.
Gazania (Gazania)
Gazanias are sun lovers. Their yellow, orange and brown blooms close up every night and slowly open with the suns rays each morning. The plants themselves are quite short at 8" tall, with thick leaves that are silver on the underside. They make up for their height in the sheer number of flowers though. Deadhead regularly to keep the flower show going. Very tolerant of windy spots too.
Globe Amaranth (Gomphrena globosa)
The flowers of globe amaranth look like very tidy versions of clover in purple or white colours (although there are now new orange, red, pink, and yellow versions available). They come in both tall and short varieties, both of which tolerate wind well. Great for cut flowers and dried flowers, retaining their flower colour for ages.
Strawflower (Helichrysum bracteatum)
Strawflowers are also called everlasting flowers and for good reason. They are the epitome of dried flowers as they will last indefinitely once cut. The flowers have crisp papery petals and can be found in a huge variety of colours.
Lantana (Lantana)
The clustered flowers of Lantana can be found in all the hot colours: yellow, orange and red. It is another hot and dry environment lover. However, this one also does well in baskets. Save it for hanging baskets located those tough hot spots in your yard. Butterflies love this stuff!
Lotus Vine (Lotus berthelotti or Lotus maculatus)
With its ferny blue-green leaves, lotus vine is typically grown for its bushy, yet trailing foliage. Although they can produce bright yellow and red flowers, they are not dependable bloomers and should be appreciated for their fantastic foliage alone. This is one of the most drought tolerant and heat loving annuals available (along with portulaca and lantana). Great for a filler in containers and hanging baskets.
Iceplant (Mesembryanthemum crystallinum)
Also known as Livingstone Daisy. The flowers are pink, red, yellow or purple and close up at night and on cloudy days, just like Gazanias do. The daisy like flowers have petals that are very narrow, giving them a light airy feeling in contrast to their wide fleshy leaves. Ice plant loves hot and dry locations. It will greatly resent overwatering. Note that there is also a perennial Ice Plant (Delosperma) which has similar flowers and succulent needle like foliage. It is borderline hardy here (Zone 4 or 5) and can often be found in local garden centres.
Chilean bellflower (Nolana paradoxa)
Large cup -shaped flowers in pale blue, violet or white with white throats and yellow centres adorn this Chilean wild flower. Its ability to grow wild in roadside ditches of its homeland portray its ability to withstand severe drought and heat. Plants are prostrate, making them perfect for planters and baskets.
African Daisy (Osteospermum ecklonis)
By far the prettiest daisy (in my humble opinion) and extremely popular in recent years. They come in an enormous range of colours, usually with a contrasting bright colour radiating out from the centre of the petals. Like many of the heat and drought tolerant annuals, the flowers do close up at night and on cloudy days.
Beafsteak Plant/Perilla (Perilla frutescens 'Crispa')
Grown mainly for its frilly edged foliage, Perilla has purplish leaves with a stunning metallic bronzy sheen. Pale lavender pink or white flowers are sometimes, but not reliably, produced. If you rub or crush the leaves, they give off a distinctive cinnamon fragrance. Size and form of this plant is very similar to their close relative Coleus.
California Bluebell (Phacelia campanularia)
These plants form short mounds of foliage with clusters of bright true blue bell shaped flowers. They are handsome mass planted at the front of the border or singly in rock gardens. Note that the leaves may cause rashes in those with sensitive skin.
Moss rose (Portulaca grandiflora)
I don't like to choose favourites, but Portulaca is my number one go-to annual for hot, dry, sunny locations. That is because it is tough as nails and can handle those harsh locations better than anyone else (although Lantana and Lotus vine would be other viable options). The flowers of this plant are exquisitely beautiful, like tiny roses. The foliage is succulent and needle shaped giving is an almost cactus like feel. It is just so pretty!
Mignonette (Reseda odorata)
Okay, I will admit this in the not the most attractive plant of the bunch, but there is a great reason for adding it to your garden: its fragrance! Yellow green flower heads top fairly standard foliage that is 35-40cm tall. They do not transplant well, so either sow them from seed outdoors or start them peat pots that can go straight into the garden. Just be sure to position them where you can enjoy their fabulous scent.
Castor Bean (Ricinus communis)
A large tropical looking plant with huge serrated palmate leaves. It is very fast growing and can get up to 10 feet in a single season, so make sure it has enough space or a very large pot. Yes, the seeds are toxic, but in our climate we don't have a long enough season to produce seeds. The leaves are only slightly toxic and very bad tasting, so rarely an issue.
Annual Sage (Salvia splendens, Salvia farinacea)
Scarlet sage (S. splendens) looks completely different than the perennial sages (usually Salvia sylvestris or Salvia nemorosa), although both enjoy lots of heat and sun. It is most often available in scarlet (no surprise there) but there are new white, pink and purple varieties on the market now as well. Mealycup sage (S. farinacea), on the other hand, is quite similar to the perennial types with spikes of lavender purple plumes. These plants are neat, tidy and extremely uniform, making them perfect for formal or structured plantings.
Fairy fan flower (Scaevola aemula)
The latin name Scaevola means left-handed, and refers the the petals on each flower being arranged on only one side, like a fan. The flowers are purple, blue or white and the foliage is short and spreading with toothed leaves. Great for baskets and planters.
Marigold (Tagetes)
This is a standard companion plant in my vegetable gardens for its use as a pest deterrent. There are African (Tagetes erecta), French (Tagetes patula) and Signet (Tagetes tenuifolia) types, all available in yellows, oranges, and reds. African marigolds are the ones with the huge flower heads and they tend to be significantly taller than the French types. In contrast, the French types of marigolds have a larger variety of petal colorations and smaller blooms. Signet marigolds have the smallest flower size and shortest stature, but the strongest smelling foliage and flowers. Position them somewhere you can appreciate their lemony scent. Signets also have edible flowers that are fantastic candied on desserts. All marigolds are a great choice for windy areas, although the shorter varieties will fare better with extreme wind.
Dahlberg Daisy (Thymophylla tenuiloba)
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A short specimen with finely divided foliage that is aromatic and very similar to thyme. Flowers are golden yellow and produce even in periods of very hot dry weather. Quite similar to Dwarf Signet Marigolds.
Canary-Bird Vine (Topaeolum peregrinum)
The only other vine (besides nasturtium) that is super drought tolerant, canary-bird vine is fast growing specimen plant with bright yellow showy flowers and lobed foliage. They grow in full sun to part shade and will quickly cover any fence or trellis available to them. They can also be allowed to grow along the ground and form a ground cover.
Nasturtium (Tropaeolum majus)
Another standard companion plant in the vegetable garden, nasturtiums encompass a huge variety of plant forms. They can be anywhere from dwarf bushy compact plants to huge trailing vines. Flowers can be double or single with colours in the white, yellow, orange and red ranges. All parts of the plants are edible: the flowers and leaves have a similar taste to watercress and the seeds are often pickled and used as caper substitutes. As a companion plant, they can be used as a trap crop for cabbage moths and their caterpillars, as well as planted with cucumbers to improve their flavour.
Verbena (Verbena hortensis)
This one is a classic for hot sunny locations. It is very long blooming and comes in a large variety of colours, usually in the white, pink, red, purple ranges. Verbena is also a great cut flower. There is also a trailing variety (Verbena peruviana) that is perfect for hanging baskets.
Honorable Mentions
Winged Everlasting (Ammobium alatum)
Scarlet Pimpernel (Anagallis arvensis)
Blue-eyed African daisy (Arctotis)
Mexican Poppy (Argemon mexicana)
Safflower (Carthamus tinctorius)
Tasselflower (Emilia coccinea)
California poppy (Eschscholzia californica)
Snow-on-the-mountain (Euphorbia marginata)
Common morning glory (Ipomoea purpurea/tricolor)
Russian statice (Psylliostachys suworowii)
Gloriosa Daisy (Rudbeckia hirta)
Creeping zinnia (Sanvitalia procumbens)
Cleome/Spider flower (Taenaya hassleriana)
Dahlberg daisy/Golden fleece (Thymophylla tenuiloba)
Mexican sunflower (Tithonia rotundifolia)
Cape daisy (Venidium fastuosum)
Dark mullein (Verbascum nigrum)
Pansy (Viola tricolor)
Immortelle (Xeranthemum annuum)
Zinnia (Zinnia elegans)
Phew, that was a lot of plants! I told you there were lots of drought tolerant options for our growing zone. Remember to water well when planting or transplanting. And look for characteristics of drought tolerance in plants when you are at the garden centre looking for new additions to your growing space. Plants that are suited to our super dry conditions will be healthier, grow better and have less issues with pests and diseases than those that are not.
Let me know if I missed any of your favourites!
Yummy gardening everyone!