This spring you’re going to see plenty of plants being promoted as ideal for your garden because they’re drought tolerant. But is this help or hype? The way I see it, if you live in a bonafide desert (or anywhere where summers naturally bring extreme heat and a lack of water from natural or artificial sources), drought tolerance is indeed helpful. But it’s not always a good thing for every garden. Before I invest in a plant touted to be drought tolerant I ask myself these 3 questions to make sure it’ll actually thrive in my garden and be a benefit to it.
1. Is this plant drought tolerant or just in familiar territory?
Plants native to your area will have a reputation for being drought tolerant simply because, once they’re established, they don’t need extra watering–they’re used to the climate as it is. Ornamental plants that originally hailed from drier parts of your country or another part of the world, on the other hand, may be drought tolerant but their tolerance may not translate well in your part of the world. See next question.
2. Are my summers really getting drier?
Never mind the weather projections for Summer 2017 calling for a warm or warmer summer than last year across southern Canada. No severe drought conditions are predicted, thank goodness (though forest fires in western Canada are likely). But if you’re concerned your region may get less rain this year, keep in mind that plants get their moisture naturally from a variety of sources including humidity, morning dew and fog. My last garden in southern Ontario often started to sag in the middle of summer when days became sticky with humidity. Unfortunately, humidity can trigger the spread of fungal diseases for “drought tolerant” plants originating from drier regions. Hello, Downy Mildew!
If your summers are naturally hot and humid, do a little research on your plant to ensure fungal diseases aren’t its weak point. (Though sometimes it’s worth taking the risk. Coreopsis is a good example. Most are native to areas south of Canada and they’re a common downy mildew host but their benefits as a supporter of beneficial insects can more than make up for its weaknesses. For more info, check out Coreopsis–A Star Reborn In the Summer Garden.
3. Can I encourage this plant to be more drought tolerant?
If being “drought tolerant” means a plant doesn’t need to be watered regularly and frequently, then, yes, you can help plants (whether they’re advertised as drought tolerant or not) to be less dependent on scheduled waterings over time. Follow these 4 steps to encourage a plant to become less high maintenance:
- When shopping for new plants, keep in mind the specific soil and light conditions for the very spot you’re trying to fill. By following the Right Place, Right Plant rule, your plant is less likely to need extra watering.
- Having said that, you do need to water well and water often during your plant’s first year in your garden to encourage roots to grow beyond their potting soil deep into the native soil of your garden. This will help the plant establish itself better and be able to cope with less waterings in future years.
- Next summer, water less but water efficiently. When you do water, make sure water isn’t running off into another part of the garden. You may have to water your plant just a little, wait for that water to sink in, then water some more, wait some more, until you’re sure that the potting soil around its roots as well as some of the native soil surrounding it is well watered.
- Use mulch generously to reduce evaporation from the soil, discourage run-off, and help keep the soil cooler.