Perennial Tough Guys
The never-say-die plants that your garden needs right now
Got a slope in the sun? Plant sedums or sempervivums.
Got a hot spot where nothing seems to grow? Plant sedums or sempervivums.
Looking for the ultimate low-maintenance plant in a sunny spot so you can enjoy lengthy times away each summer? Plant sedums or sempervivums.
Do you have plant-and-forget insect and disease problems? You’ve got it – plant sedums or sempervivums.
If there is a difficult job to do in the sunny garden, you can count on one family of plants to pull through. Do you remember the ‘hens and chicks’ that your grandmother had in her rock garden? Those were sempervivums (closely related to sedum) and chances are, if the garden still exists, so do the hens and chicks.
The secret to their long-term survival rate is their ability to store water in their leaves for long periods of time. They are the camels and dromedaries of the plant world and they make fabulous garden plants.
The meaning of ‘sempervivum’ is ‘always living’ but unlike many other plants that you can say this about, such as common mint for example, these plants seldom make a nuisance of themselves by spreading where they are not wanted. And if they do, it does not take much effort with a sharp hoe to flip them out of the soil and into the compost.
The same shallow roots that make them easy to move around the yard also make them easy to propagate and adaptable to poor (gravelly or sandy) soil conditions. That is why they have been popular for use in rock gardens for generations. For that matter, few plants do as well in the shallow recesses of rockery stone as these succulents.
The most aggressive sedums are the ‘spurium’ types, such as Dragon’s Blood and TriColor. They spread quickly once established and flower beautifully early to mid-summer. Dragon’s Blood produces a stunning red carpet of flowers that turns heads, while TriColor is best known for the three colours of its leaves. Spurium sedums only grow to 10 cm high at maturity, so they lend themselves well to a steep slope where erosion control is desired.
For a fast groundcover, space each plant about 20 to 25 cm apart, depending on the size of the plants that you are starting with. They spread horizontally quickly, knitting into a consistent carpet after one or two seasons.
For Perennial Gardens
The standard ‘Stonecrop’ that most of us think of is actually ‘spectabile.’ It grows about 45 to 60 cm tall and even if you ignore it for a whole summer, it will reward you with flowers in September through October in the red/pink/rose end of the spectrum. Butterflies and honeybees frequent sedum spectabile.
Leave large flowering sedum standing over the winter to allow songbirds to feed on the seeds of the finished flowers.
Dig And Divide
This is the perfect time of year to dig and divide established sedums and the smaller, lower growing sempervivums. Use a sharp spade or shovel to gently remove the mother plant from the soil and then cut it into halves and quarters using the same spade, shovel or a kitchen knife. Replant these smaller divisions around your yard or give them to your neighbours if you run out of room.
If you have a hard time finding a broad selection of sedums and sempervivums at your local garden retailer, perhaps one of the reasons is that they have become the number one choice for people wanting to plant up a green roof. They require little attention once established, and that is reason enough to seek out a variety of colourful, winter-hardy succulents to plant on the roof of your house, your doghouse or your tool shed. We think it’s a great idea for esthetic appeal and for environmental reasons. You will cool your home (or the dog’s house), slow storm water run-off, filter rainwater and produce oxygen rather than a heat sink, as we do when we use asphalt shingles on a sloped roof or tar and gravel on a flat roof.
The Enemy: Too Much Water
If there are a couple things that hardy succulents do not like (besides shade), it is too much water and heavy, clay soil. After planting, you will have to water them, but as time passes, you will learn to ignore your sedums and sempervivums. Remind yourself why you planted them in the first place: to reduce the maintenance around your garden. If your soil is heavy with clay, deposit generous quantities of sharp sand to open it up and allow for good drainage.
There are lots of benefits to growing the humble sedum and sempervivums. If you are blessed with some sunny, hot spots in your garden, you won’t go wrong by planting a few.
Mark Cullen is a Member of the Order of Canada. He reaches over 2 million Canadians with his gardening/environment messages every week. Receive his free monthly newsletter at www.markcullen.com Ben Cullen is a professional gardener with a keen interest in food gardening and the environment. You can follow both Mark and Ben on Twitter (@MarkCullen4), Facebook (https://www.facebook.com/MarkCullenGardening/) and Instagram (https://www.instagram.com/markcullengardening/).