Gardening Advice: Perennials, Going Postal

Gardening Advice: Perennials, Going Postal

October 5, 2001

Q: I’m tempted by the rare varieties I see in perennial catalogs, but isn’t buying plants through the mail risky? What are the odds that they will thrive, not just survive?Andrea Pascal, Bloomington, Ind.

A: The odds are getting better all the time. When I first bought mail-order perennials about 20 years ago, everything was shipped as bare-root dormant plants. Most of these bare-root plants grew well for me, but some needed a year or more to recover and grow strongly. A few died, no matter how much I pampered them. Even though the mail-order nurseries had a money-back guarantee (as most still do), I expected these plants not just to live, but to flourish, and when they didn’t I was very disappointed.     

In the past growers typically dug up large masses of these specimens in the fall and stored them at freezing or near-freezing temperatures in a warehouse. Later they’d let them thaw and then divide them into many smaller, bare-root pieces for shipping. Today at least half the growers have added another stage — planting the divisions in containers — which has greatly improved the plants’ chances of thriving. They have the benefit of growing for six or more weeks in their small pots before being shipped, usually arriving with at least a bit of green showing above the potting soil. So even if you can’t find the time to plant them right away, chances are good that they’ll do well if placed outdoors in a sunny spot and watered regularly. A handful of tough perennials don’t really benefit from the container treatment: Daylilies, hostas, irises, and peonies are so easily grown from bare-root divisions that it’s pointless to search for container-grown versions. In these cases, bare-root specimens are usually cheaper and the selections better. Most other perennials, however, are best bought in containers. But if you fall in love with a variety that’s not available in containers, don’t pass it up — just be prepared to give the bare-root plants extra attention.

That extra attention starts from the beginning: Put your order in early and plant the little things the day you receive them. The biggest threats to bare-root nursery stock are warm temperatures and dry air. You want roots that have spent the least amount of time between the cold storage and your garden soil. Spending just a few days on a truck will damage plants far more than will standing for months in a frigid warehouse. Moreover, three days in March cause much less damage than three days in May. So order early, at least a month before planting. For most hardy perennials, the ideal planting time is early in spring, just as soon as the ground has thawed and become dry enough to be workable. For my technically zone 6 (but usually zone 7) garden, this is about the time the daffodils come into bloom. You’ll need to nurture bare-root perennials the way you would annual flowers or vegetable seedlings. Remember, these will be very small divisions, which may give you a bloom or two this summer, but don’t expect them to make a major color statement in the landscape. So don’t fuss about their location: Set the little plants in a row somewhere close at hand, where you can tend to them while they recover their strength. Water them weekly if it doesn’t rain, and weed regularly; give them a bit of fertilizer or compost once they’re up and growing well enough to compete with weeds and more established perennials. If you baby them a bit, the odds are very good that they will be stocky plants by the end of summer — maybe even big enough to divide and certainly ready to make a strong display of flowers in their second summer.