- How to determine if the summer lilac has frozen
- Buddleia frozen back rescue operations
- Young summer lilacs are more sensitive
In general, the summer lilac is considered to be very frost-tolerant and hardy to around minus 20 °C. However, this does not apply to all species and varieties, but only to Buddleja davidii, also known as butterfly bush. Rarer species such as the globe summer lilac (Buddleja globosa), on the other hand, are not hardy. But even the robust Buddleja davidii can freeze back in severe frost - but it usually sprout again.
If it gets cold again in spring, the summer lilac can freeze to death
How to determine if the summer lilac has frozen
Frosty winters usually don't bother planted buddleia. It only becomes problematic in late winter/early spring, when the weather and incidence of light signal the plant's "beginning of spring" and it gradually wakes up from hibernation. A frosty night at this time can have fatal consequences, not only for the summer lilac. Therefore, you should always cover it with a protective fleece during late frosts, which you remove again during the day. However, if the bush has frozen, you can use the thumbnail test to determine whether it is still alive. To do this, carefully scratch the bark on several shoots with your thumbnail so that the underlying layer becomes visible. If this is green, the bush is still alive and can be started again.
Buddleia frozen back rescue operations
You should “put frozen buddleia on the stick”, as the gardener says. For this purpose, shorten all shoots to about 20 to 30 centimeters, so that the shrub puts its energy into new shoots. You can support it by carefully working a generous handful of horn shavings (€32.93) and a generous shovel of compost into the soil around the root disk. After that, the only thing that helps is waiting - since summer lilac is very robust, it will in all probability sprout again.
Young summer lilacs are more sensitive
However, you should be particularly careful with young buddleia: These are much more sensitive than older, well-rooted and therefore established specimens and therefore freeze back faster. A light winter protection during the winter months can prevent freezing. The same applies to Buddleia cultivated in pots, which in any case do not have the same hardiness as their outdoor relatives. Proper winter protection or even frost-free hibernation in a cool, bright room can be useful here.
tips
Due to its sheer size, not all varieties of summer lilac are suitable for pot culture. Only the variants that remain small should be cultivated here.