Osteospermum (African daisies) can stay green all winter if you prepare them well. They are hardy plants that look great all year round. While they will only have a few flowers over winter they will be covering with flowers in spring if you deadhead the plant, fertilize them at the start of spring and surround them with bark mulch.
This article will explore all you need to know about caring for osteospermum over winter and how to get them ready for the cold weather.
8 Ways to care for your osteospermum over winter
Check out my top 8 ways to care for your osteospermum plants over winter so you get loads of flowers in spring.
1. Prune at the end of Fall
Prepare osteospermum before the cold weather hits so they look great over the winter months. Osteospermum will slow their growth over winter and can survive very cold temperatures and frosts. At the end of fall take sharp secateurs and trim off old flower heads.
Fall is the best time to shape your osteospermum. They can grow rapidly and spread over a 4-5 foot area, so you can remove extra stems that have started to take over other areas. My osteospermum has grown from 4-5 inches across to around 4 feet wide.
Before winter arrives, I like to shape the plant by removing the lower branches that are starting to grow over the lawn or to grow over my nearby dianthus. This will keep the osteospermum in this basic shape over winter and the new flowers will grow right where you want them.
2. Add slow release fertilizer
Add slow release fertilizer to the soil under the daisies during the middle of Fall before winter arrives. This will allow the plant to absorb the nutrients before winter which will strengthen it and help it to survive the cold.
Choose a well balanced fertilizer based on organic matter. Pelleted chicken manure works well and you can top dress with aged manures. Mix together aged cow manure and compost and sprinkle around the base of the plant. Avoid putting the mix on the main stem and water it all in well.
Avoid adding fertilizer in winter as the daisy’s growth will slow and it could burn the roots.
3. Mulch around the base of the plant
Mulch is important for osteospermum over winter because any area that is not covered by the stems will start to grow weeds. Mulch will help to insulate the plant from very cold weather and protect the roots. Use bark mulch because it takes at least 4 months to break down.
It is best to layer some aged cow manure on the soil first to give the plant a small amount of nitrogen to offset the bit that will be taken up when the mulch starts to break down.
4. Water sparingly
Osteospermum only need small amounts of water over winter as they slow their growth. They are drought hardy so can survive any dry spells I will usually water them every 2 weeks over winter if they are not getting watered by the rain.
The soil will dry out much slower when the weather is cooler so it is important not to overwater the plant.
5. Move potted daisies indoors or under protection
If you live in an area with harsh winters you can to bring your African daisies indoors. Place them in a sunny position where they can receive at least six hours of sunlight per day. You can also place them under a verandah where they are protected from the winter winds and snow.
6. Watch out for pests
Check the leaves of your African Daisies for common pests such as aphids, spider mites, or whiteflies. If you spot any, treat the plant with Neem oil. Repeat the process again if the bugs are still there after 1 week.
7. Check for diseases
African daisies can be prone to fungal diseases like powdery mildew over winter. Look out for grey, white or black marks on the leaves. Treat the plants with fungicide if the mildew is spreading and avoid watering directly on the leaves.
8. Move them gradually into the sun in Spring
As winter ends and the weather warms up, gradually move your African daisies outdoors before transplanting them outside. This process, known as hardening off, helps the plants adjust to direct sunlight and outdoor temperatures.
Caring for osteospermum in winter FAQ
How do you overwinter African daisies?
African daisies can be protected over winter by adding a thin layer of cow manure on the soil, a handful of pelleted chicken manure and a 3 inch layer of bark mulch around the base of the plant.
Water all of this in well to feed the plant gently, protect the soil and the soil bacteria over winter. Do this at the end of fall before the cold weather hits and remove any damaged stems or flowers to keep the plant looking neat.
Can African daisies (osteospermum) survive frost?
African daisies can survive frost so they are a great plant for very cold regions. Prepare the plant for winter by feeding it with a balanced organic fertilizer and mulch and it will stay green all year. While you will get few flowers over winter it will be covered in spring if you prepare it well.
When the weather warms in early spring and the chance of frost has passed, trim off any damaged or brown leaves to keep the plant looking neat.
Do you cut back osteospermum for winter?
I like to cut back osteospermum to a neat shape over winter. Osteospermum will grow very slowly over winter so it will maintain its shape over this time. I like to shape the plant at the start of winter and I won’t need to trim it again until after its first flowering in spring.
After it has flowered in spring you can deadhead the whole plant, remove all of the flowers and you will have another coverage in 2-3 weeks.
African daisy winter growing tips
Here are my top tips for keeping osteospermum (African daisies) happy over winter.
- Plant new osteospermum in fall before the winter weather arrives so that they have time to settle in and establish their roots.
- Plant flowering annuals next to osteospermum to bring some color into the space.
- Plant osteospermum in pots so you can move them around to the sunniest spot in winter. This will keep them growing strong and give you early flowers.
- Plant African daisies near your citrus trees to attract bees in early spring. Trim back any dead flower heads so they flower as early as possible in spring or even late winter.
Osteospermum care over winter | Summary
Osteospermum or African daisies will survive even very cold winters with some proper preparation. Add some general, all purpose fertilizer in spring and remove any old flowers. African daisies are one my favorite plants because they are so easy to grow they can survive drought when they are established and they can flower from late winter all the way to fall.
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.