In contrast to the native Ilex, the Japanese holly, Ilex crenata, is only partially hardy. This is especially true for young plants. This is how you get the decorative hedge plant through the winter.
Is Ilex crenata hardy and how do I protect it in winter?
Japanese holly, Ilex crenata, is hardy for older plants, while young plants require frost protection. Outdoors they should be in a protected location with a mulch cover and not fertilized too late. Potted plants need additional winter protection and regular watering on frost-free days.
How hardy is Ilex crenata?
Ilex crenata can generally cope with low temperatures. However, this only applies to older plants that have been in the same place for a long time. They have a well-developed root system and the shoots are also mature, so the cold doesn't bother them that much.
You need to protect younger Ilex crenata from frost.
Overwintering Ilex crenata outdoors
- Choose a protected location
- Lay out mulch cover
- don’t fertilize too late
- maybe. Put on fleece
When planting, make sure you have a place where it is not too drafty, as too much draft is very hard on the Ilex, especially in winter.
Place a layer of mulch under the plants. You can use lawn clippings, bark mulch, leaves and other garden debris. The mulch cover not only protects against frost, but also prevents the soil from drying out too much.
You can also protect young plants from frost with garden fleece (€6.00 on Amazon) or brushwood.
Don’t fertilize Ilex crenata too late
You actually don't need to fertilize the Japanese holly. However, if you don't want to do without fertilizer completely, you should add additional nutrients until the end of July at the latest.
If you fertilize later, the new shoots will no longer be able to harden properly and will freeze to death in frosty temperatures.
How to overwinter Japanese holly in a pot
If you care for Ilex crenata in a pot, you should always ensure winter protection. The soil freezes much faster in the pot than in the open ground.
If you have to overwinter the plants outside, place the pot on an insulating surface. Choose a place where there is little draft and where there is enough light. The location should not be too humid either.
Bright basements, garages or attics are well suited for wintering.
Tip
Ilex crenata does not like waterlogging, but it cannot tolerate complete dryness either. Especially in very dry winters, you should definitely water the Japanese holly on frost-free days so that it doesn't dry out.
