Gardening Perennials Pruning

Forced Perennials: Off With Their Heads!

Question: I have trouble keeping my echinaceas alive. I buy them in full bloom in the spring and they seem to do all right, blooming much of the summer, but the next spring, they just don’t come back. Yet I think I plant them under good conditions—full sun, good soil, good drainage — , fertilize regularly and water as needed. And I live in zone 5, which should be fine. What am I doing wrong?

E. F.

Answer: You’re buying the wrong ones. When spring plant shopping, always prefer echinaceas that are young and healthy, but with only green foliage, not flowers. If you buy echinaceas in spring in full bloom, they’ve been greenhouse-forced: pushed into bloom before their time. This results in weakened, short-lived plants.

Echinaceas or purple coneflowers (Echinacea cvs) normally bloom from mid to late summer into fall. If they’re in bloom in May, they’ve been grown in heated greenhouses under special conditions to push then into early bloom. This is called forcing. It certainly stimulates sales (who doesn’t want to see what colors their garden plants are going to be at purchase time rather than having to wait a few months?), but it weakens the plant. 

While it is blooming, the plant puts on little to no root growth, investing its energy in blooming and preparing for seed production. Thus, it never has time to settle in and get ready for winter. 

Cut flowers and buds from off-season perennials before you plant them. Photo:, montage:

The next time you buy an echinacea in bloom in spring (or indeed any other late-blooming perennial in flower off-season), cut off all the flowers as soon as you get home. Plant it and care for it as you would any other perennial. With its flowers removed, it will move into “settling-in mode” and start to grow deep, solid roots, giving you a tougher plant much more likely to survive. 

In fact, if it tries to flower a second time at the end of the summer, cut those flowers off too. No blooms the first year will give you a well-established tough plant that should bloom for years to come. 

This same technique—removing the first-year blooms of forced perennials—should in fact by applied to all sorts of perennials purchased in full bloom in the spring, but that really shouldn’t be in bloom at that season: rudbeckias, gaillardias, garden phlox, etc. 

Don’t let any perennial bloom before its time, not if you want it to behave as a perennial.

Garden writer and blogger, author of 65 gardening books, lecturer and communicator, the Laidback Gardener, Larry Hodgson, passed away in October 2022. Known for his great generosity, his thoroughness and his sense of humor, he reached several generations of amateur and professional gardeners over his 40-year career. Thanks to his son, Mathieu Hodgson, and a team of contributors, will continue its mission of demystifying gardening and making it more accessible to all.

3 comments on “Forced Perennials: Off With Their Heads!

  1. Do you recommend that for ornamental shrubs as well? For example roses, gardenias?

    • It’s best to remove flowers from any plant that has been forced before you plant it out, including shrubs. I’m sure there are exceptions, but I honestly can’t think of any!

  2. One of the more unpleasant jobs on the farm was breaking the flowers off of the daphne to promote fluffier foliar growth.

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