We know them in bloom in a wide variety of colors. Whether on the windowsill in the living room, in the balcony box or in the garden bed, primroses ensure spring feelings. But what happens to them in winter? Can they tolerate frost?
Can primroses tolerate frost in winter?
Are primroses hardy? Most primroses are sensitive to frost and do not tolerate temperatures below -5 °C. Tropical primroses are not hardy. Cushion primroses, cyclamen and cowslips, on the other hand, survive frost better. Protect primroses in the bed with leaves and brushwood or place potted primroses indoors when temperatures are below -2 °C.
Primroses – few species are sensitive to frost
Primrose family includes a wide range of species. Depending on the species, they inhabit high mountains in Europe and Asia, regions of the Arctic, the tropics or other climes. This results in considerable differences in tolerance to low temperatures.
Primroses, which come from the tropics, are not frost-hardy and should be kept in this country over the winter. Even well-known primrose species such as the cup primrose are not very resistant to frost. On the other hand, cushion primroses, cyclamens and cowslips cope well with frost.
It becomes critical from -5 °C
For most primroses, things become critical when the thermometer reading falls below -5 °C. The rhizomes in the ground can survive these sub-zero temperatures. But the flower buds, which tend to open between January and April, tolerate such low temperatures poorly.
To protect them, all you need to do is cover the primroses with some newspaper. As soon as the temperatures rise again, the newspaper can be removed. This is the only way the flowers have a chance to open.
Protect sensitive primroses in the bed
Primroses that are in the garden bed should be protected in harsh winter times. Various materials can be used to protect them. A mixture of leaves and brushwood has proven successful. Other suitable materials are:
- fleece
- Compost soil
- Spruce or fir branches
- Moss
- Bark mulch
Primroses in pots should always be protected in winter
Primroses in pots can be kept outside on the balcony or terrace or indoors over the winter. For wintering outside:
- Place the pot on the wall of the house (protection from freezing rain, snow, east wind, etc.)
- Wrap the pot with fleece or newspaper
For wintering indoors:
- Place primroses at temperatures below -2 °C
- do not put in the living room
- Suitable locations: garage, basement, attic, hallway
- Keep soil moderately moist
- do not fertilize
Tips & Tricks
If you buy primroses in winter, you should not plant them immediately. Since they spent most of their time in the warm greenhouse, they have to slowly get used to lower outside temperatures. Otherwise they will get a frost shock.