We want to enjoy its impressive flowers every summer. So the question of the winter hardiness of butterfly lilac is obvious. Read here to what extent a butterfly bush tolerates frosty temperatures. Benefit from our tips for he althy wintering in beds and pots.
Is butterfly lilac hardy?
Butterfly lilac (Buddleja davidii) is hardy with a frost tolerance of up to -20 degrees Celsius, but only as an established plant. In the planting year and the following 3-4 years it needs winter protection with layers of leaves, brushwood or fleece. Container plants should be protected annually.
Winter hardiness builds up gradually
In contrast to native flowering bushes, the Asian butterfly bush has to develop its winter hardiness from year to year. Only as an established, well-rooted plant does your Buddleja davidii in the bed have a frost tolerance of up to -20 degrees Celsius. In the planting year and in the following 3 to 4 years, help your flower tower with the following precautions:
- Leave the fallen leaves lying around in autumn
- Use additional leaves and brushwood to create a protective layer of 10 to 20 cm on the root disc
- Water a little in dry winter weather
Since the shoots are cut in late winter anyway, further measures are unnecessary at this point. If delayed ground frosts are expected after budding in spring, protect the young branches from frost damage with a fleece cover.
Winter protection in the bucket is indispensable every year
In contrast to its counterparts in the bed, a butterfly bush in a pot depends on the following precautions every year in order to survive the cold season unscathed. How to do it right:
- Before the onset of winter, move the pot under a canopy or in front of a house wall
- Place the vessel on a wooden block and cover it with bubble wrap (€14.00 on Amazon)
- Cover the substrate with autumn leaves, wood shavings or straw
In harsh winter regions, ideally place the pot in a sturdy wooden box whose bottom is covered with bark mulch. You can also fill the spaces between the wooden wall and the bucket with mulch. Furthermore, the root disc receives a layer of leaves as winter protection. Water the butterfly bush occasionally during the winter to prevent the root ball from drying out.
Tip
Limiting winter hardiness to a base value of -20 degrees Celsius does not affect the seeds. If a butterfly bush is given the opportunity to distribute its seeds in the bed, the seeds will survive even bitter frost. To prevent the neophyte from spreading invasively, cut off the withered flowers in good time in late summer.