You CAN fool Mother Nature by deadheading!
I get a LOT of questions about deadheading. Deadheading is removing spent, or exhausted and used up, blooms from flowering plants. It is most often done on annuals, such as petunias, and to roses.
The most common reason for deadheading is the urge towards tidiness–deadheaded plants simply look better. The more important reason for deadheading is that it can trick the plant into re-blooming, or re-blooming more frequently, or profusely. Done regularly and correctly, deadheading can extend the blooming life of a plant for several months.
Many gardeners deadhead their perennials, such as Shasta daisies and coneflowers, because they look prety ragged once the blooms expire. Some perennials will produce a second bloom after deadheading, but perennials are designed to put their all into their primary bloom, which can last for a couple of weeks. I deadhead perennials just enough to keep them tidy, but I try to let them go to seed naturally, because birds like the seed heads.
Annuals live for a year, or more accurately, one growing season. Left to their own devices, annuals will bloom until they’ve exhausted the bloom cycle, and then they’ll begin to set seeds. Once there are enough seeds on the plant to trigger change, the plants begin to withdraw support from blooming and focus on getting ready to produce a crop of seeds. They can’t help it–it’s what they do. Deadheading allows the gardener to trick the plant into thinking it needs to bloom again, because deadheading remove the seeds that would normally trigger the plant to go into its seed setting cycle. When you deadhead annuals, you get to mess with Mother Nature–you get to intervene in natural processes. How often does THAT happen?!
Most deadheading of annuals is pretty simple–if you remove the faded bloom, you usually remove the source of the seeds. The annual that seems to require the most deadheading is petunias–they really look dreadful when they’ve passed their peak. However, if you simply pull off the faded blooms and don’t also remove the seed cap at the bottom of the bloom, you’re not removing the seeds–you’ll get a tidier plant, but you won’t get a second or third bloom. The little green seed caps must be removed in order to trick a petunia to rebloom.
I learned this the hard way, because as much as I tidied up my petunias, they never seemed to burst back into life like my neighbor’s petunias always did. I thought I wasn’t feeding them enough, or that they were getting too much sun, or that I had a black petunia thumb, and it didn’t occur to me to ask anyone about the correct deadheading technique–I had no idea there was a “technique” with petunias. After years of thinking I simply couldn’t grow petunias, I stumbled onto the “secret” and learned to clip off the cap when I removed the blooms–what a difference!
I made the same mistake when I decided to grow one of those Moonflower plants. The huge white blooms look really nasty when they fade, so I always pulled them off the plants when went out each morning to say hello to the new blooms. Then it occured to me that if I removed the seed cap at the base of the blooms, I could interfere with the plant’s ferocious habit of setting huge, spiky seed balls that could explode and sow Moonflower over every inch of my garden. I started deading the plant with scissors, so that I could cut the bloom and the cap off the stem, and most of the seed pods disappeared. Amazing! Not that the plant was stymied in its effort to become huge and invasive–have you ever tried to dig out a Moonflower? Those roots! Those things are monsters!
Most modern roses are designed to rebloom, so even if you don’t deadhead your roses, you’ll get sporadic re-bloom. However, assiduous deadheading, besides improving the look of the bushes, can hurry reblooming along, and make sure the plant’s energy is directed to blooming rather than setting seed. Modern roses literally beg to be cut, and they reward you for cutting them by producing more blooms.
Old Garden Roses (OGRs), which are all the roses in existence before 1867, do not usually rebloom. They bloom in the spring, and they can show those blooms for up to a month, but after that, they rarely bloom again until the following spring. Deadheading keeps the roses looking tidy, but won’t trigger the urge to re-bloom. Again, they can’t help it–it’s just the way they are.
Next up: So, how DO I deadhead roses?