Even though lilac - botanically Syringa vulgaris - can be found in many gardens and is sometimes very old, it is still not a native plant. In fact, the popular flowering tree was introduced to our latitudes from southeastern Europe in the 16th century and was able to quickly establish itself here due to its robustness. In fact, lilacs are sufficiently hardy and do not need any special protection as long as they are not in a pot.
How to protect lilacs in winter?
To protect lilacs in winter, young shrubs or potted plants need special care: layer of mulch on the root disc, warming fleece around the planter or protection from late frosts with fleece. Noble lilacs are more frost-resistant than old lilac varieties.
Overwintering lilacs properly – this is how it works
If it is a lilac planted in the garden, it is usually sufficiently hardy and only needs winter protection in two cases:
- It is a young, freshly planted specimen.
- The lilac is cultivated in a planter.
Young lilac bushes first have to build up their winter hardiness and can be a bit sensitive, especially in the first two to three years. However, you can protect them with a thick layer of mulch on the root disc, although if possible you should not use bark mulch. This material keeps the water in the ground, which the lilac doesn't like. However, spruce or fir branches spread out on the ground are very suitable. For lilacs grown in pots, you should wrap the planters with a warming fleece (€72.00 on Amazon) and place the pot on an insulating surface (for example made of wood or Styrofoam).
Be careful of late frosts: protective fleece often makes sense
In some regions of Germany, late night frosts can still occur even in May. These particularly threaten the flowering and shoots of the lilac, as both can freeze back due to the sudden cold combined with otherwise warm weather. Therefore, if frost is imminent, you should protect the above-ground parts of the lilac with a fleece or similar, provided the bush is not yet too large.
Carry out radical cuts in winter
A radical pruning of lilacs is actually only necessary if an old bush is already heavily bare and needs to be rejuvenated in this way. If possible, carry out this cut in late winter, during the vegetation break, and choose a frost-free and dry day for it.
Tip
New noble lilacs are often more robust than the old lilac varieties when it comes to frost sensitivity. They are specifically bred for winter hardiness and disease resistance.