How do I deadhead my plants? And why?
I discussed deadheading last week on The Garden Lady and later in the program a caller remarked that it was suddenly clear to her how, and why, this garden task should be done. This listener isn’t alone in wondering why the removal of wilted flowers is important. So I thought it important to talk about it again here.
Here are the reasons to deadhead plants, and some photos that illustrate how and why.
1. Removing the old flowers often stimulates the plant to bloom more. Yay! This is because it is every plant’s mission to push its genetics into the future, and the main way plants do this is by making seeds. The flowers are the way the plant attracts pollinators, but once seeds are formed the plant figures that its job is done, and no more pollinator bait is needed. But if we clip off the seeds as they start to develop, the plant has to produce more flowers in order to fulfill its mission. Not all plants will respond to deadheading by flowering more, but many do. The key piece of information here is to clip the growing seeds off below the swollen area under the wilted petals – removing the dying flower petals alone won’t stimulate more bloom if the seeds are left in place.
Deadheading means cutting off the dried, dying or dead flowers once they have wilted and no longer look good. This Diva lacecap was in bloom for over a month, but now the flowers aren’t as attractive and I can clip the stem off just below the bloom.
Sometimes deadheading can revive a plant that’s stopped flowering because of summer heat or inconsistent watering.
2. Clipping off dead or drying flowers improves the look of the plant. Once old flowers are gone the garden looks better. In some cases, like the hydrangea pictured above, just clipping off the spent bloom directly underneath it is perfect. In other cases, like daylilies, you need to remove the stem that supported those flowers too. Just plucking off the flowers on a daylily or geranium stem, for example, leaves the bare stem and this isn’t attractive.
3. Removing developing seeds prevents unwanted “volunteers” from showing up in your garden. Sometimes self-seeded volunteers such as foxgloves are welcomed. But let’s face it, there are some plants that are land-grabbers. Give them an inch and they’ll take over your landscape before moving on to conquer the entire neighborhood. I love my Verbascum chaixii, for example, but if I let every plant set seeds that’s all you’d see in my flower beds. Some plants need to have limits set, and deadheading is one way of keeping them under control.
4. Deadheading plants that bloom early in the summer opens up valuable real estate. My Nepeta ‘Walker’s Low’ is lovely though early July, but after that the blue flowers fade to gray and it doesn’t bring much to the party. By cutting off the long stems not only is the look of the garden improved, but the plant is made smaller and I have space to stick in a few more annuals. (Note: I always buy a few extra six packs of annuals and plant them up in 6″ pots in early June so that I have some plants to tuck into the garden later in July. Profusion Zinnias are some of my favorites for this purpose.)
Here are some photos that illustrate what these reasons to deadhead, plus one that shows how you can usually tell the difference between a seed pod and a flower bud.
This container was planted with a dark-foliage Dahlia and some orange Torenia plants in early June. In order to keep the dahlia flowering, and to stimulate new booms on the Torenia, deadheading is needed. Often flowers that are fading do just that – the colors fade to a lighter shade. That’s one way to tell which ones you cut off. Newer blooms will be deeper and more vibrant in color.
Here is how the pot looked after I removed the fading flowers on the Dahlia and clipped about 2″ off the top of the Torenia. Neater, cleaner, and ready to produce more flowers. After deadheading, water the container well and then give it an application of fertilizer to help stimulate more blooming.
Annuals usually flower more with deadheading. This Mexican sunflower (Tithonia rotundifolia) will branch out and bloom more if old flowers and seeds are removed.
Even plants that don’t require deadheading, like this Bidens Campfire FIreburst, flower better for the rest of the summer if they are given a haircut to cut off spent blooms. This plant slowed its flowering in our hot, dry July weather so a trim, and a good soaking, will help it to rebound.
Here is a Volcano Purple Phlox that is just starting to go by. This plant will produce many more huge flower stems (more than most Phlox paniculata!) if the old ones are cut off promptly.
I left the flowers that were still coming out, but next week I’ll go back and clip those off as they fade.
Pink flowering Spireas are improved in appearance and will produce more flowers when deadheaded.
Here is how Double Play Artist looks after the old, gray flowers are removed. Within a couple of weeks this plant will have fresh foliage and it will produce more pink flowers in August. You can see from the clippings in the bucket that I cut off stems about 6″ long when deadheading this plant.
Cut off the stems (see red line) as well as the old flowers on geraniums and daylilies.
Peonies don’t bloom more when deadheaded but the look of the plant is improved when these seeds are cut off. Clip these stems down into the foliage so the cut doesn’t show.
On some plants the seed pods and the buds look similar. Here’s how you can tell the difference. The seed pods are usually a different shape. On this dahlia the seeds are longer and thinner; the three on the left are seed pods, while the rounder three stems on the right are flower buds. On Stella D’Oro daylilies, however, the shape difference is just opposite: the flower buds are thinner and the seeds are rounder. Look at the shape of each plant’s buds as they start to open into flowers, and see what the difference is between those and the seeds for that particular plant.
There’s a myth that roses need to be deadheaded by cutting down to just above a set of 5 leaflets. Don’t believe it! (Get a copy of Coffee for Roses and read all about this and other garden falsehoods.) Clip off spent flowers at any point below the cluster of growing rose seeds. (Rose seed pods are called “hips.”)
Nepeta looks OK as it goes past bloom, but the faded flowers don’t add much and they take up lots of room.
You can either cut the entire plant to the ground (it will make some new, fresh low leaves) or do what I did and clip off the long flower stems, leaving a rounder, smaller plant. The Nepeta will fill out and produce a few new flowers in August, but best of all, removing those long stems creates more space.
Look at all that valuable real estate where more Profusion Zinnias can be planted!
Deadheading can be done in fifteen to twenty minute segments and you can do it on a plant by plant or garden by garden basis. Stroll through the garden with a cup of coffee in the AM or the beverage of your choice in the early evening, and sip a bit here and there. You’ll be amazed at the results.