Dianthus can be cut down to the ground in winter to hibernate and be ready to grow back in spring. Frost can damage dianthus over winter so cut them back to prevent damage. The plant will stay dormant over the winter and when the weather warms in spring it will grow rapidly and grow new flowers.
I planted three dianthus plants in fall which flowered and then started to die off during winter. I pruned them down close to the ground, kept them watered and in spring they grew rapidly and produced a large coverage of flowers.
This article will explore the four simple steps to cutting back dianthus for winter to prepare them to grow back in spring.
How to prune dianthus for winter – 5 Steps
Here are my top tips to prune dianthus for winter to keep them healthy to grow back in spring.
1. Wait for the cool weather to arrive
Dianthus will be ready to be cut back after they have finished flowering and the weather cools in winter. When the frosts arrive, the leaves and stems will wilt and they can be burnt by the frost.
I noticed that the leaves of my dianthus started to wilt over at the start of winter. That is when they are ready to be pruned back.
2. Trim dianthus stems off near the ground
Dianthus can handle a harsh pruning and the stems can be cut all the way down to the ground. I cut mine back to the ground leaving only a short stem of around 1 inch. This seems harsh but dianthus are hardy and they will grow back.
Grab the whole plant and use sharp secateurs to remove the top leaves. Place them in your compost or green waste bin.
3. Surround with bark mulch
Once the dianthus has been cut back I like to surround the base with new bark chips. I don’t like to put mulch over the top of the stems but will leave them exposed so that they get sunlight when the weather warms.
For areas that get very harsh frosts you can place a light layer of straw mulch over the stems to protect them. I live in an area with mild winters so I don’t need the added protection over the top of the stems. If you live in a very cold area, give them the added cover to protect them over the harshest cold weather.
4. Wait for the dianthus to grow back in spring
Keep the dianthus watered over winter and when the warmer weather arrives in spring the dianthus will grow back. It took around 6 weeks for the plant to grow back to full size and to be covered in flower buds. They have just started to bloom and it is around 6-8 weeks into spring.
Looking after dianthus by pruning them back harshly in winter was the best way to get a healthy plant covered in flowers in the next spring.
5. Add some pelleted chicken manure to the dianthus in spring
Add a handful of pelleted chicken manure to the dianthus when the green leaves start to appear. The chicken manure will give it a boost of nitrogen to encourage healthy leaf growth. After a few weeks you will get flowers covering the plant which will bloom rapidly.
Dianthus flowers only seem to last a day or two but the plant produces many flowers over and over again. Keep trimming the old flowers off during spring to encourage dianthus to keep growing new ones.
Cutting dianthus right to the ground
The best way to prepare dianthus for winter is to cut the plants close to the ground. Leave around 1 inch of stem on the plant and you can forget about the plant (almost) completely over winter. I only watered the dianthus when I was passing by and remembered.
Will dianthus rebloom if cut back?
Dianthus are hardy plants that will grow back if they are cut back harshly. You can leave the plants roots protected in the ground while the cold winter weather passes. Dianthus will grow back and can flower during spring, summer and fall.
When should I cut back dianthus?
It is best to cut back dianthus after the cold weather arrives. At the beginning of winter you can remove the stems and leaves before they are damaged by frosts but don’t worry if you do this later in the season. Any sign of leaf damage means you can go ahead and trim the dianthus back.
Deadheading dianthus is the best thing you can do to keep your dianthus plant blooming all summer long. Pinch off flower heads with your fingertips or use secateurs to trim them off instead.
You can remove the top inch of the plant and flowers in one go and the plant will grow back with a new coverage of flowers. Deadhead dianthus regularly throughout the season to keep it flowering.
How to cut back dianthus for winter | Summary
Dianthus can be cut back at the start of winter to the ground to protect the leaves and stems. You can place a light layer of straw over the top if you have harsh winters or you can leave them exposed if you have milder winters. In spring you can see new stems and leaves grow through and the plant will be in bloom within 6-8 weeks.
Dianthus are a fantastic perennial plant but can be removed completely to grow them as an annual. Otherwise, prune them down to the ground and then forget about them before they pop back up spring.
Dianthus is a bright beautiful flower that comes in a range of colors from deep red, to pink and whites. They are beautiful annuals or great perennials if you protect them over winter.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.