Deadheading is a pruning technique for removing flowers once they’ve finished in order to encourage plants to direct their energy into producing new flowers and extend their flowering period, rather expending their energy reserves on old spent flowers to produce seeds.
Removing spent flowers is also done for aesthetic reasons, as a plant covered in dead flowers is not visually pleasing. Deadheading therefore is also a garden maintenance task to keeps plants looking tidy throughout their flowering season, ensuring that they look their best.
How Does Deadheading Work?
Flowering plants produce seeds as part of their reproductive cycle, it’s the way that they create new baby plants, and give rise to the next generation.
When we deadhead a plant by removing the flowers as soon as they begin to fade, before they set seed, we essentially prevent seed production. Since the plant is intent on successfully reproducing to pass on its genetics to the next generation, it will produce more flowers in an attempt to make new seeds.
In practice, the best time to remove flowers is as soon as their appearance begins to decline, well before the plant begins using its limited energy stores to start forming seeds. Producing seed pods or fruits (such as rosehips) uses a lot of the plant’s energy, and by removing them early, we can save more of the plant’s energy for blooming (flowering).
How To Deadhead Roses
Some roses produce a single flower on each stem, while others bloom in a cluster of flowers. Floribunda roses for example produce blooms in large clusters, while hybrid tea roses tend to produce single flowers or small groups of up to around three flowers.
When deadheading, we use the leaves below the flower as a guide for where to make the pruning cut.
Roses have compound leaves, made of 3 or 5 smaller leaflets, and have a pinnate structure, with rows of leaves on either side of the extended leaf stem which is known as the rachis.
There are two types of compound leaves on the stems of roses. They usually have one or two compound leaves with 3 leaflets directly below the flower, with two or more compound leaves with 5 leaflets below them.
The bud at the base of the compound leaf with 5 leaflets is the one which will produce the new stem that will flower. We know this because if we leave the spent roses intact and don’t prune them, this is where the new shoots emerge, as shown in the picture below.
The new shoots don’t grow from the base of the compound leaf with only 3 leaflets that are found directly below the flower.
Knowing that roses grow new flowering shoots above leaves with 5 leaflets, we can make our pruning cuts in the right place, as explained further in the instructions below.
How to Deadhead Roses with Single Flowers
When deadheading roses with a single flower on each stem, snip off the spent flowerhead by cutting the stem about 6mm (1/4″) above a leaf with five leaflets (not three) to stimulate reblooming. The new flowering shoot will grow from the bud at the base of the leaf joint.
Use sharp secateurs or pruning snips to make the cut parallel to the angle of the leaf. Preferably, select an outward-facing, 5-leaflet leaf to make the cut above, as this will direct the new shoot outwards for the centre of the plant.
How to Deadhead Roses with Clusters of Flowers
For roses that produce clusters of flowers on each stem, we use a two-step procedure for deadheading.
Step 1. Deadheading roses – Removing a single spent flower
Snip off each spent flower from the cluster as the petals begin to drop. Cut them off where the flower stalk joins the stem of the plant. Leave any remaining buds or blooms to continue flowering.
This step is mainly aesthetic, keeping the plant looking good while the rest of the buds open and flower.
Step 2. Deadheading roses – Removing the flower cluster
Once all the flowers in a cluster have finished, we can remove the whole stem of the cluster, to encourage new blooms and helps to maintain a compact shape.
The procedure is the same as for deadheading a single stem flowering rose, simply snip off the whole finished flower cluster by cutting the stem about 6mm (1/4″) above an outward-facing, 5-leaflet leaf to promote further flowering.
What Happens When Roses Aren’t Deadheaded?
Roses are one of the flowering plants that benefit particularly well from deadheading. If rose flowers aren’t pruned off after they begin to decline, they will eventually turn into rosehips, these are the red or orange, round, seed-filled bulbs which are found underneath the rose petals.
Some gardeners choose not to deadhead the last flowers for the season to allow the rosehips to develop for ornamental purposes, or to gather them for culinary purposes.
Rosehips are in fact edible, and are used for making rosehip syrup, jams, jellies, vinegar, and can also be dried and used as a tea. They don’t all taste great though, the best tasting rosehips are from the Dog Rose (Rosa canina), though the Japanese Rose (Rosa rugosa) is also very popular as it produces extremely large rosehips, but they’re quite watery in flavour making them not so good for use in syrups.
It’s important to point out that just beneath the flesh of the rosehip fruit is a layer of hairs around the seeds that can cause irritation to the mouth and digestive tract if ingested.
References
- Pennsylvania State University Extension, Master Gardener Program, Deadheading <https://extension.psu.edu/programs/master-gardener/counties/chester/how-to-gardening-brochures/deadheading-1>
- South Dakota State University Extension, Enjoy More Flowers in Your Garden by Deadheading Regularly <https://extension.sdstate.edu/enjoy-more-flowers-your-garden-deadheading-regularly>
- Iowa State University Extension and Outreach, Horticulture and Home Pest News, Deadheading of flowers <https://hortnews.extension.iastate.edu/1996/6-28-1996/deadhead.html>