I got an email from a client yesterday asking if she should deadhead spent hydrangea blossoms, and since there seems to be fairly widespread confusion about what to remove when, here’s the five-minute drill on deadheading.
Let me start by saying that, while deadheading is a form of pruning, I’m not talking here about removing tree limbs, or thinning out an overgrown quince or rejuvenating an old lilac. Deadheading refers just to the removal of spent flowers from a plant, an ornamental shrub or tree. I’ll tackle the grittier aspects of pruning in another format, but I will say here that if any of your shrubs or trees suffers from one or more of the three D’s, you should tackle it immediately. What are the three D’s? Dead, diseased or damaged. If you’re not comfortable enough with your own skill level to handle the problem, ask for help. If you even suspect the plant’s in trouble, don’t wait.
That said, let me give you the same answer I gave Andrea about deadheading her hydrangea. She’s got three varieties, but this applies to all the so-called mophead hydrangeas like Nikko and Endless Summer and Annabelle: for a summer-flowering shrub, it really doesn’t matter. If it’s early in the season and a blossom has gone by, by all means remove it. Later in the season, and throughout the Fall, some people like to leave them on and watch them caramelize, and some don’t. With the PeeGees and the Tardivas and the Limelights, the whole point is to watch them turn that fabulous copper color, so don’t whack those before you enjoy the show, but for the others, it’s really your choice.
With the spring-flowering shrubs, it’s a little more complicated, but far from complex. My preferred technique is to cut the blossoms while they’re in bloom, and to use them the same way I use all the other cut flowers. I do that because the first word of flowering shrub is ‘flower,’ and it seems to me like damn fool nonsense, as my father would have said, not to enjoy them. The other reason is that I’m going to have to dead-head the thing eventually, anyway, and it’s more enjoyable to me to gather sheaves of flowers than to dead-head a shrub. I grant you, I often get into the zone where dead-heading becomes a meditation of sorts, but for the most part, I’d rather gather.
The chief reason to dead-head Spring-flowering shrubs is not cosmetic, it’s to ensure that the plant puts all of its energy into setting itself up for the next year. Removing the spent bloom tells the plant “Okay, show’s over; move on.” You can do this by hand or with shears, depending on the plant. For example, I take my shears to lilac, but use thumb and forefinger on the rhodies. This takes a bit of practice because the old flower is nestled between the new shoots and you may wind up taking more than you intend, but you’ve got a couple of hundred chances to get it right, so keep at it.
There is one codicil to this: dead-heading should never be done to any plant that sets fruit or berries, because those lovely little fertilized clusters will become the things you want either to eat or to admire. There’s also a half-codicil, I suppose, in that any shrub that sets inconsequential blooms — red osier dogwood comes to mind — will have inconsequential spent blooms, and since removing them won’t make next year’s blossoms of any greater significance, don’t bother. You, too, should move on, and spend your energy where it will do the most good.
There are lots of perennials I do let go to seed, just for fun, and although I remove the spent flowers of Siberian iris, I think the seed pods have a certain drama that carries the plant through the remainder of the season. This year I’m allowing the seed pods of some yellow Bearded iris to ripen, but since the seeds of a hybrid plant often revert to the parent stock, I’m not at all certain what they will produce. If it’s anything fabulous, I’ll let you know. For the most part, though, when the show’s over, I lop off their heads, and for certain plants, whack them back entirely. If it’s early enough in the season, they may do an encore. It’s seldom as vibrant as the first, but it’s something, although I have to say that the chives I whacked at the end of June because they went by so fast, have come back with great speed and in full.
So there’s the skinny: gather ye rosebuds — and lilac and laurel — while ye may, and if you have forgotten to gather, gather up your gloves and your pruning shears and have at it. It’s good for your plants and good therapy, to boot. Trust me on this; the next time you’re upset, spend half an hour or so in the garden snipping off every dead little head you can find. You’ll be amazed how much better you feel!