Photo/Illustration: Tracy DiSabato-Aust, courtesy of Timber Press
As a garden designer and speaker, I often talk about how foliage texture and form can provide the backbone to a perennial garden. But, as a gardener, I have to admit that I want a lot of flowers in addition to interesting foliage. Planting long-blooming perennials is one way to keep the floral display going. Deadheading—the practice of removing spent blossoms—is another way to keep your garden in flowers.
Deadheading refreshes a plant's appearance, controls seed dispersal, and redirects a plant's energy from seed production to root and vegetative growth. However, I do it primarily to prolong the bloom period or encourage a second flush of blooms on some perennials. I also do it to keep other perennials tidy.
Deadheading is a maintenance practice that can be done throughout the growing season, from spring until autumn. The best time to deadhead a flower is when its appearance begins to decline. How often you'll have to deadhead a particular plant depends on the life span of its blooms, which can range from a day to several weeks, depending on the species. Weather also greatly affects a flower's longevity. During moist, cool summers, flowers will last much longer than they will during a season of sweltering heat. Torrential rains also take their toll on blossoms.
Choosing the exact point to make a deadheading cut can seem confusing, since perennials have different flower forms. Because deadheading, like other types of pruning, is so species specific, it can be difficult to group plants into categories. For most plants, however, all you need to remember is to prune spent flowers and stems back to a point where there's a new lateral flower or bud. If no new flower is apparent, prune the stem back to a lateral leaf.
Many gardeners find deadheading enjoyable and relaxing. In fact, for me, it's very meditative and centering. But if you do not fall into this camp, the best way to keep from feeling overwhelmed is to visit your garden daily and do a little at a time. I've found that once I get into a schedule of deadheading on a regular basis, the waves of blooms in my garden can be extended by weeks or even months.
Deadheading for rebloom
Many perennials respond to deadheading by producing more blooms. Plants, like the shasta daisy (Leucanthemum X superbum cv.), that produce lateral flowers along their stems should be deadheaded according to the method illustrated here.
Alternate method —
Perennials that have spikelike blossoms that bloom from bottom to top, like this delphinium (Delphinium spp. and cvs.) and the other examples marked by an asterisk (*) on the list below, should also be deadheaded as shown above, but only after the stem is about 70 percent finished flowering.
Deadheading to improve appearance
Not all perennials will continue to bloom after deadheading, but many look better as a result. The one-time or single-flowering daylily (Hemerocallis cv.) shown at right is just one example.
Perennials to deadhead to improve appearance —
Baskets of gold (Aurinia saxatilis and cvs.)
Bearded irises (Iris spp. and cvs.)
Bergenias (Bergenia cordifolia and cvs.)
Catmints (Nepeta × faassenii and cvs.)
Clustered bellflowers (Campanula glomerata and cvs.)
Common rue (Ruta graveolens)
Coral bells (Heuchera spp. and cvs.)
Daylilies (Hemerocallis spp. and cvs.)
Goatsbeards (Aruncus dioicus and cvs.)
Golden stars (Chrysogonum virginianum and cvs.)
Hellebores (Helleborus orientalis and cvs.)
Hostas (Hosta spp. and cvs.)
Jacob's ladders (Polemonium caeruleum and cvs.)
Japanese anemones (Anemone × hybrida cvs.)
Lady's mantles (Alchemilla mollis and cvs.)
Lambs' ears (Stachys byzantina and cvs.)
Lavender cottons (Santolina chamaecyparissus and cvs.)
Lungworts (Pulmonaria spp. and cvs.)
Mulleins (Verbascum spp. and cvs.)
Obedient plants (Physostegia virginiana and cvs.)
Pearly everlastings (Anaphalis triplinervis and cvs.)
Peonies (Paeonia spp. and cvs.)
Red hot pokers (Kniphofia spp. and cvs.)
Rodgersias (Rodgersia aesculifolia and cvs.)
Rose mallows (Hibiscus moscheutos and cvs.)
Scotch thistles (Onopordum nervosum and cvs.)
Sea thrifts (Armeria maritima and cvs.)
Wall germanders (Teucrium chamaedrys and cvs.)
Wall rock cresses (Arabis caucasica and cvs.)
Western bleeding hearts (Dicentra formosa and cvs.)
Western mugworts (Artemisia ludoviciana and cvs.)
