Immortelle are actually annual plants. But there are also perennial varieties that you have to bring well over the winter.
Did you know that there are over 600 different types of everlasting flowers? Many of these species, including the well-known helichrysum, are annuals and need to be resown each year (information on this here). Perennial species such as the Italian helichrysum or the helichrysum, on the other hand, can get you through the cold season well. And even in the garden! You don't even have to pay that much attention to it.
Winter immortelle indoors
If your everlasting flowers (helichrysum) are growing in a bed, it is advisable to dig them up together with the roots in autumn and transplant them into a pot or tub. You then bring this bucket into the house. Choose a bright location in an unheated room. 12 degrees Celsius are ideal for the plant. However, three to four degrees more or less does not harm the plant either.
Do not fertilize the helichrysum during the dormant period and water sparingly. It is sufficient if the soil in the bucket does not dry out completely. On the other hand, too much moisture damages the roots in winter.
If you then want to put out the helichrysum again in spring, you should wait until after the ice saints in mid-May. However, spring frosts are rarely severe. By the end of March at the latest, it is very unlikely that the everlasting flowers will suffer frost damage.
Winter helichrysum in the garden
It is also possible to overwinter perennial helichrysum outdoors. Many species are frost hardy, but only tolerate relatively mild temperatures of around -5 degrees Celsius. If the temperature drops significantly below this for a long period of time, the plant will probably not survive. However, there are some safeguards you can take to prevent this from happening:
❶ Cover the shoots with branches of coniferous trees such as spruce or fir.
❷ Surround the helichrysum with a thick layer of mulch or fall foliage to protect the roots.
❸ Shade the plant with a shading net, for example, or simply place the pots with the plants closer to the house. A great dangerin addition to severe frost, is that the water in the tubs thaws too quickly. This leads to tears in the cell walls of the plant. In contrast, frozen water thaws more slowly in the shade.
Our tip for all cases: grow cuttings as a replacement
Have you decided to leave your straw flowers well protected in the garden during the winter? Then grow a few cuttings in smaller pots during the summer months and only overwinter these pots indoors. If the mother plant dies off in the cold season, you will at least have a nice replacement in spring. However, cuttings can only be taken from sufficiently woody species and specimens. There are other ways you can propagate helichrysum.