Beautiful Perennials that Tolerate Drought and High TemperaturesYou would have to live under a rock to not realize that our weather is changing drastically. From heat domes to record-breaking cold winters, and atmospheric rivers to virtually no rain for months on end, we are staring down new territory when it comes to gardening. And since we are in the midst of some extreme drought and high temperatures, I thought I would point out a few perennials that tolerate both, but only once established.
We have come a long way in Penstemon breeding and while most hybrids were derived from North American prairie species, they can thrive here with good drainage. Colours range from true blues to purples and the deepest reds, many with contrasting throats. They make excellent cut flowers and are much favoured by hummingbirds.
Russian Sage (Perovskia)
An excellent companion for tall ornamental grasses, the long-blooming season (July-October) and dwarf varieties (‘Little Spire’) make this a versatile perennial. The flowers are also edible with a delightful sage flavour that can be added to cocktails (think savoury Caesar or Bloody Mary) or salads. One hint to successful overwintering is to leave the woody stems intact through winter, cutting them back to 6” when growth is evident.
This favourite butterfly flower is also quite cold hardy (zone 3) and even tolerates very poor, sandy soils. They make good cut and dried flowers, with the umbels coming in a myriad of colours including reds, pinks, yellows and whites. Two of my favourite varieties are older introductions, ‘Terracotta’ (changing yellow to salmon-orange blooms) and ‘Moonshine’ with its contrasting silvery foliage.
Hens & Chicks (Sempervivum)
Do you have a small planter by your west or south-facing front door that plagues you with guilt because you are constantly forgetting to water it? I have a simple solution: plant a tapestry of different coloured Hens & Chicks with a little golden Sedum ‘Angelina’ for some contrast. Once it is established, you can forget to water it for days without any impact on the overall display.
Anise Hyssop (Agastache)
This perennial performs really well in its first year and now comes in just about any colour imaginable, although you will want to stick to those hot red, orange, and deep violet varieties that hold up well to the wash of bright sun. Add to that a delicious fruity-licorice scent and the undivided attention of bees and butterflies, and you have a great addition to any garden space.
While we have been having some trouble overwintering Spanish Lavender (Lavandula stoechas zone 7) due to cold winters, both the English (L. angustifolia) and Provence (L. x intermedia) are much hardier at zone 5. That said, few shrubby perennials provide us with such enticing fragrances coming from plentiful stalks of rich blue to purple (white and pink forms are also available). The flowers from both the latter species are also edible and can be used sparingly (they have a strong flavour) when baking.
Shasta Daisy (Leucanthemum)
Shasta Daisies are actually making a pretty strong comeback, much in part to the insightful breeding which has brought us pale yellow varieties and cultivars with fringed petals. The bloom period lasts from June to September and they always perform better when deadheaded regularly. Divide your clumps every 2-3 years to keep them in optimal form.
I think everyone is aware of the explosion in Coneflower varieties of late, starting with the ‘Cheyenne Spirit’ strain. True reds, deep oranges, bright yellows, and fully double forms are all quite commonplace now, but if you want continual flowers from July to early October, you are going to have to deadhead weekly, which will also keep the butterflies happy. Towards the end of the season, you can leave some of the seedheads to develop, as finches and other birds will gladly raid your garden for some winter fare.
There are generally two types of Sedums, either low or tall-growing varieties. The lower forms such as ‘Coral Carpet’ or ‘Dragon’s Blood’ work well as low-maintenance groundcovers, while the taller cultivars such as the long-established ‘Autumn Joy’ and ‘Brilliant’ (now classified as Hylotelephium) work well mid-border, as do newer varieties such as ‘Back in Black’ and ‘Autumn Fire’. A happy medium would be ‘Atlantis’ with its moderate height and striking cream-variegated foliage.
Blanket Flower (Gaillardia)
This short-lived perennial tolerates heat and drought admirably and will bloom itself to death if you let it. For better longevity prune off all flowers in early September and be sure to deadhead regularly before that. These brilliant perennials come in hues of red, bright yellow, orange, as well as bicolour and often smother their entire canopy with eye-popping blossoms.