To Deadhead or Not to Deadhead...
When and how to deadhead is a common question for gardeners.
The phrase Deadhead has a whole different meaning for those of us who are gardeners, rather than the general public out there. If you google either Dead Head or deadhead the search results will return information on fans of the Grateful Dead not the act of removing spent blooms from plants. It takes typing in ‘Gardening Deadhead’ to get results that will be helpful in learning more about keeping plants in bloom.
I am often the person who answers questions sent in by gardeners and recently one of the most common questions has been when and how to deadhead specific plants. In this article I will give a brief summary of why deadheading is sometimes necessary, how you should deadhead, and which Proven Winners® plants need deadheading.
First, what exactly is deadheading? This gardening term simply means to remove the old spent blooms including any developing seed from a plant to help keep it blooming longer.
Your next question is likely to be “Why does a plant bloom more if you remove old flowers?” In the grand scheme of things flowers are meant to ensure survival of the species. All of the various blooms that nature developed (not plant breeders) are an attempt to ensure that seeds are produced and the next generation of plants develops. In some cases, once seed has been produced thus ensuring the survival of the species, the plant will stop blooming since there is no reason to put energy into blooming any longer.
It was probably a gardener that figured out removing old flowers before they produce seed will keep plants blooming longer. This can be a rather time consuming endeavor, but many times is considered a labor of love. In more recent times, plant breeders have put a lot of effort into increasing the blooming time of plants. Someone then realized that sterile plants, those that do not produce seed, will bloom continuously even when you don’t deadhead. These plants keep on trying, unsuccessfully, to produce seed so they keep producing flowers. Rather frustrating for the plant, but easy for the gardener.
As time has gone on plant breeders have put a lot of effort into choosing plants that will continue to bloom without deadheading. Sometimes this is because the flowers are sterile and sometimes it is simply because it is possible to choose plants who are prolific bloomers despite setting seed. Proven Winners® tries to select plants that are prolific bloomers, but still are “low maintenance,” which generally means that they don’t need to be deadheaded. Another part of “low-maintenance” refers to the fact that many of our plants are “self-cleaning”. This simply means that wind or other factors will cause the flowers to either blow off the plant or simply melt away leaving no old flower to remove. Now if only my car was self-cleaning!
Choosing plants that don’t need deadheading would certainly be the easiest route to continuous flowers. However, in some cases there will be a plant you can’t do without, even though deadheading is required, or perhaps the sight of old blooms still hanging on to plants will be unsightly enough that you want to remove them anyway. In these cases knowing how to properly deadhead will be necessary.
In most cases, when deadheading you can simply remove the old flower by pinching off the stem just below the base of the flower. This will remove the old flower and keep it from producing seed – the goal of deadheading. If the flower stem is large or you don’t want to stain your fingernails green, you may find using pruning shears or scissors to be a better choice. Please note that simply pulling off the dead flower petals without removing the developing seed pod does not increase flower production since the seeds will still develop.
Any flower can be removed just above the first leaf below the flower head without affecting the rest of the plant. For plants with larger stems removing just the flower may leave an ugly stem exposed. Cutting just above the first leaf, will remove the unsightly stem as well as the flower. This is also the preferred method of deadheading for plants that bloom with spikes of flowers. New research has recently shown that even roses flower more prolifically when old flowers are removed just above the first leaf below the flower rather than at the first set of 5 leaves (this is the standard method promoted by most people).
For many gardeners deadheading is a time consuming chore they simply don’t have the time to perform. Some newer varieties of plants that used to have to be deadheaded, for instance Supertunia® petunias, are tailor made for these time-starved gardeners. However, there are gardeners that find deadheading to be a great excuse to spend time in the garden, a time honored tradition, a way to relax at the end of a busy day or even a Zen-like activity. If you are a gardener who enjoys deadheading, never fear. Even though the plants may no longer need deadheading to bloom continuously, doing so will not harm the plants. Feel free to remove as many spent flowers as you wish.
While a good rule of thumb is always nice to have, a list of how to deadhead specific plants is also useful. Below is a quick rundown of our Proven Winners plants and some notes on deadheading.
Deadheading not necessary for Continuous Bloom
Ageratum Artist® – they will “bury their dead” (this simply means the new flowers will quickly cover the old flowers) so no dead heading is necessary. This is not true of other series of Ageratum.
Angelonia Angelface® - self-cleaning, no deadheading needed
Argyranthemum – removing old blooms may improve appearance.
Bidens – The petals are self cleaning, however, seed heads persist and removing them can improve appearance. Deadheading will not improve flower production.
Bracteantha Sundaze® – removing old blooms may improve appearance
Calibrachoa Superbells® – self-cleaning, no deadheading needed
Chrysocephalum Flambe® Yellow – self-cleaning, no deadheading needed
Cleome Señorita Rosalita® - the plants are seed sterile, self-cleaning, deadheading isn’t necessary
Diascia Flirtation® – self-cleaning, no deadheading needed
Euphorbia Hybrid Diamond Frost® – self-cleaning, no deadheading needed
Gaura Stratosphere® and Karalee® – each flowering stem adds blooms, continuously to the end of the spike. As time goes on the flowering stems can get rather long and tangled. Although deadheading isn’t necessary for continued blooming you may find that you prefer to trim back some of the flowering stems at some point in mid-summer. This will encourage new flowering stems to emerge. Flowers will be closer to the foliage and the plant will look tidier. If you choose, you can trim all the flower stems off at once, however, you should then expect a 2 to 3 week period without flowers.
Heuchera Dolce® – They begin blooming in early spring. Deadheading won’t keep them blooming longer. However, removing the flower stems once the plant has finished blooming will keep them looking tidier.
Impatiens Rockapulco® - self-cleaning, no deadheading needed
Impatiens Infinity® - self-cleaning, no deadheading needed
Lamium Pink Chablis® – self-cleaning, no deadheading needed
Lantana Luscious® – self cleaning, no deadheading needed
Lobelia Laguna™ and Lucia® – self-cleaning, no deadheading needed
Lobularia Snow Princess® - self-cleaning, no deadheading needed
Mecardonia GoldDust™ – self-cleaning, no deadheading needed
Nemesia – self-cleaning, no deadheading needed
Oxalis Charmed® – self-cleaning, no deadheading needed
Petunia Supertunia® – self-cleaning, no deadheading necesary, this is not necessarily true of all Petunias. You may want to remove old blooms of Supertunia® doubles since these larger flowers sometimes remain on the plant. Leaving them will not affect flowering.
Phlox Intensia® - self-cleaning, no deadheading needed, this may not be true of all phlox.
Sanvitalia Sunbini® – “buries its dead”
Sedum – the seed heads will remain on this summer to fall blooming plant. Removing them will not keep the plant blooming longer. Many people consider the seed heads to be attractive and will allow them to remain on the plant throughout the winter before removing them as part of their garden spring cleaning.
Solenostemon Coleus ColorBlaze® - Coleus are grown for foliage, our plants are selected to bloom late in the season because blooming usually signals a decrease in foliage quality. Removal of flower spikes will help keep the foliage looking good.
Sutera Snowstorm®– self-cleaning, no deadheading needed
Patent Info: New Wonder® Scaevola aemula 'Newon' PP: 10584 Can.: 1710; Sunbini Sanvitalia 'Starbini Superbini' PP: 17869 Can.: 2827; GoldDust™ Mecardonia hybrid 'USMECA8205' PPAF Can. PBRAF; Snow Princess® Lobularia hybrid 'Inlbusnopr' PP: 21594 Can. Can.: 4189; Pink Chablis® Lamium maculatum 'Checkin' PP: 17925; Simply Scentsational® Heliotropium hybrid 'USHTRP0303' PP: 21681 Can.: 4140; Karalee® Petite Pink Gaura lindheimeri 'Star Pink' PP: 19496 Can.: 3424; Helena's Blush Euphorbia amygdaloides hybrid 'Inneuphhel' PP: 17555 Can.: 2829; Kalipso Euphorbia hybrid 'Imprkalip' PP: 16948 Can.: 2726; Efanthia Euphorbia amygdaloides hybrid 'Imprefant' PP: 16908 Can.: 2725; Diamond Frost® Euphorbia hybrid 'Inneuphdia' PP: 17567 Can.: 2830; Senorita Rosalita® Cleome hybrid 'Inncleosr' PP: 19733 Can. Can.: 3290; Flambe® Yellow Chrysocephalum apiculatum 'Flochryel' PP: 19175 Can.: 3280; Slightly Strawberry™ Anisodontea hybrid 'Nuanilainp' PP: 21393