How A Tedious Task Can Reap Huge Benefits

Your garden looked great last week, but now you have stalks of spent flowers, little brown or shriveled reminders of past glory.  What to do?  Deadhead.

Cutting off the dead blooms not only neatens the garden’s appearance but also has these additional values.

  1. Prolonging the bloom.  Many perennials will bloom longer if you cut off the spent flowers before they set their seeds.  Why?  Flowers create seeds, and if the flowers sense that they haven’t successfully made seeds they will try again.  Some flowers will even set up a second set of blooms from side shoots.       Balloon Flower, Shasta Daisies, Coreopsis, Speedwell, and Coneflower are among these flowers.
  2. Prevent unwanted new plants.  Some perennials just love to cast their seed around, gradually taking over your garden.  If you spend too much time      weeding unwanted “volunteers” then deadhead before the seeds form!  Garden Phlox, Feverfew, and Yarrow are among these plants.  And of course this also applies to annuals.  Cleome, Alyssum and even Tomatoes are notorious re-seeders.
  3. Keep your plants healthy.  Some plants expend a great deal of energy making seeds.  If you prevent seeds from forming your plant will be healthier as it waits “till next year” to try to set seeds.  Spring bulbs (like Tulips and Daffodils), Daylilies and Iris are among these flowers.

How should I deadhead?  You will need scissors or pruners to complete this operation, but first take a look at your perennial.  The shape of the plant will determine what happens next.

  1. Individual flowers.  You can just snip off the individual flowers (and their stems) like your Spring Bulbs, Daylilies and Balloon Flowers.
  2. Flower clusters deserve the extra work you’ll find with these flowers.  There are side shoots to look for, tiny flowers waiting their turn to bloom once the first flower has finished.  So you’ll be deadheading  in steps, but the plant will thank your patience by continuing its bloom.  Watch for the side shoots on Shasta Daisies, Salvia, Garden Phlox and Bee Balm.  When all of the side shoots have bloomed you can cut the stem back to the ground.  (You can also do this if you’re tired of deadheading and don’t want to wait for the second bloom.  It won’t hurt the plant, but you’ll lose the blossoms you’ve been waiting for.)
  3. Too many dead blooms to deadhead?  Sheer them!  Give ‘em a haircut.  Dianthus respond well to this.  And many plants can be cut to 1”-2” above the ground.  They will totally re-grow and look fresh and neat for the rest of the growing season.  Columbine, Perennial Geranium (Cranesbill), Threadleaf Coreopsis, and Jacob’s Ladder are among these flowers.

Is there anything I shouldn’t deadhead?  You can deadhead most of your perennials, but there are some that look nice even after they’re spent.  They go to seed and feed the birds or provide material for dried floral arrangements.  These plants include the conical heads of Astilbe, the black-brown centers of Black-Eyed Susans, the spiky centers of Coneflower, the graceful plumes of landscape grasses and the brown, flat heads of Autumn Joy Sedum.

And so, as you sharpen your pruners and get ready to get to work, remember the famous words of the Queen of Hearts in Alice in Wonderland, “Off with their heads!” It’s your deadheading theme all summer.

Posted on August 6, 2013 .