Lupins are probably one of the most robust ornamental perennials in the garden. They can tolerate sub-zero temperatures and can survive without any winter protection in winter. Only if you keep lupins in pots on the terrace do you need to protect them from temperatures that are too low.
Are lupins hardy and do they need winter protection?
Lupins are hardy and can easily survive temperatures down to -25 degrees Celsius. Outdoors they do not require winter protection, while potted lupins should be protected from drought by covering them and insulating the pot.
Overwintering lupins outdoors
Lupins that grow freely in the garden do not need to be protected from frost. They even survive temperatures of minus 25 degrees without any problems. The perennial forms long roots that can penetrate up to two meters into the ground. This means that the plant has access to groundwater even when it is cold and does not dry out completely even in sub-zero temperatures.
It is often recommended to cut the lupins down to the ground in autumn for overwintering. Of course you can do that. However, this is not necessary.
Most of the above-ground components absorb themselves over the winter. The remains remain on the surface and are overgrown by new shoots in spring. In this way they serve as additional fertilizer.
Protect lupins in the pot from frost
Lupins in pots do not necessarily freeze to death at low temperatures. What really damages them is the dryness. It occurs when the moisture in the ground has frozen rock hard and the roots can no longer absorb liquid.
The lupine is more likely to dry out. That's why it needs winter protection so that it can absorb some water even in winter.
- Place pot on Styrofoam plate
- Cover plant with branches of conifers
- Cover the pot with bubble wrap, bags or cardboard
- Place the pot in a corner protected from the wind
- During long dry periods, give some water
Preparations for winter
Short the lupine in the pot and cut off all the inflorescences. You don't have to cut the plant down completely.
Cover the surface with permeable material. Fir branches are well suited because they keep out the cold but still allow moisture to pass through. The earth will then not mold.
Tips & Tricks
Older plants that no longer produce as many flowers should be pulled out in the fall. If you divide the roots and plant the sections before winter, you will get young plants. They bloom the following year, so the missing perennials are not even noticeable.
