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Wintering summer lilacs: Start now to prepare the butterfly bush for the cold season!

Butterfly bush, still known as summer lilac, is a beautiful shrub that often decorates the home garden. In this country, it is grown both as a garden plant, and as a container plant. In order for it to please the eye with its fragrant flower buds year after year, proper care is very important. This also includes overwintering. We have summarized the most important tips for the fall and explain how to overwinter the summer lilac.

Overwintering summer lilacs: How to get the garden plant through the winter well

Overwintering butterfly bushes Care for butterfly bushes in September Prepare for winter

The butterfly bush is a hardy plant. Nevertheless, it needs suitable protection so that it can survive the cold season without any problems. In the wine regions, around the rivers and in the southern parts of Germany, where the climate is mild and winters – almost frost-free, a layer of mulch is completely sufficient as winter protection.

In northern Germany, the plant sheds its leaves and the tips of the shoots can also freeze. If temperatures fall below -25° Celsius, even all above-ground parts of the plant could die. But this does not mean that the whole plant will die. The butterfly bush will sprout again the next year.

Should I cut back the butterfly bush in the fall?

Pruning butterfly bushes in autumn tips

Usually, pruning is done in late winter or spring for the butterfly bush. However, if strong winds and snowstorms are not uncommon in your area between November and March, you may want to do some pruning of the shrub in the fall. The right time for this is late September, early October at the latest. Only in this way can the plant recover from the nurturing pruning before the frost sets in. Proceed as follows:

  • Remove all dead plant parts
  • Cut off all shoots growing inwards
  • Shorten all other shoots by one third.

Planting the garden plant in a pot: September is the right time.

Alternatively, you can plant smaller plants in containers and overwinter them indoors. The right time for this is early autumn. This gives the woody plant enough time to get used to the new situation. In October, you can then gradually reduce the watering. In this way you give the shrub a sign that the cold period is about to begin. For him, this means the beginning of the rest period.

Care for butterfly bushes in autumn Cut off wilted flowers

The butterfly bush that you transplanted into a container in September can spend the winter outside. Provided that you wrap the pot with fleece and place it in a wind-protected place (preferably directly in front of the house wall) in the garden. A saucer made of styrofoam can additionally protect the roots from frost.

Plants that have at least four weeks to adapt to the new conditions and environment, can be t the end of October into the mulch layer as winter protection.

Wintering butterfly bush outdoors

Protect butterfly bushes from frost tips


If winter temperatures do not fall below – 20 degrees Celsius, then you can overwinter the shrub outdoors. For this purpose, lay a 5 cm to 7 cm layer of mulch over the bed. The mulch will protect the roots from frost and also prevent water from evaporating too quickly.

Propagate summer lilac and overwinter the cuttings

If you have propagated summer lilac via cuttings in late summer, then you can plant the seedlings in the garden in the fall. However, they need sufficient frost protection. Lay a layer of mulch 10 cm thick on the root zone. Cover the above-ground parts of the plant with winter protection made of fleece.

Overwintering butterfly bushes in pots

Summer lilac overwintering in a pot tips on care

Compact summer lilac varieties that are suitable for keeping in pots can be overwintered both indoors and outdoors. Of course, here too there are certain rules or tips that make the gardener’s job easier.

Leave summer lilac outside

If you want to overwinter the summer lilac outside, then place it against a house wall or in a wind-protected place in the garden. It is also important to protect it from rain, as too much water can lead to rot. The best place is a covered terrace or the covered entrance to the house.

Place the tub on a saucer made of styrofoam. Tie fleece loosely around the tub and fill the space between with mulch or autumn leaves. Add another 7 cm layer of mulch to the bottom.

You can wrap the above-ground parts of the plant with special translucent fleece, but it is not absolutely necessary. If the roots are well protected, then the next year the woody plant will quickly recover and sprout again. Even if the shoots dry up completely in the winter, it can still bloom vigorously the next summer. This is because it blooms on this year’s wood.

Wintering summer lilac indoors

If you want to play it safe, if the summer lilac was recently purchased or if you are caring for it as a houseplant anyway, you can overwinter it indoors. Do not place the shrub directly on the windowsill, but in an off-sun place.

Butterfly bush in pot overwinter indoors or outdoors


Care in the winter quarters: As far as care is concerned, the butterfly bush is quite undemanding. It needs regular watering (although you should water it much less during the dormant season). Fertilizing is discontinued completely during the winter months. Remove any ailing shoots or yellow leaves.

At what temperature to overwinter the butterfly bush?

Butterfly bush care in autumn and summer lilac wintering and pruning

In winter, the shrub thrives best at a room temperature of up to 10° Celsius. In this way, you will prevent it from freezing and all its shoots wither. Then, the next year, the container plant will sprout again with full force and will form flowers in the summer.