Can An Older Hydrangeas Plant Have A Rose Collar Placed Around It With Straw During Winter?

Question

I have received several older hydrangeas plants and would like to know if it would help to place rose collars with straw on them during the winter months to help root system? I will be planting soon. I live at 7100′, zone 5 in Southeastern Colorado. Thank you for your article and help.

Answer 1

Yes, you can add the collars for additional warmth during the winter. You don't say what type of hydrangeas you have, but the only type I would really be concerned about are the macrophylla types, also called big leaf or mopheads. They are generally hardy only to USDA zone 6, and they are famous for getting nipped by frosts in early spring. They bloom on old wood, so the buds are already formed. If that is the type you have, I suggest more coverage than just the root zone. They would benefit from the entire shrubs being covered. For example, you can surround the shrubs with chicken wire and fill those with straw or leaves, or something similar.

Other types of hydrangeas are hardier and a thick mulch over the root zone should suffice. Also, planting them in sheltered areas away from harsh wind helps. The hydrangeas that bloom on new wood, H. paniculata and H. arborescens are the best choice for cold zones.

Here is more:

https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/mophead-hydrangea-care.htm

https://www.gardeningknowhow.com/plant-problems/environmental/protecting-plants-winter.htm

https://www.gardeningknowhow.com/plant-problems/environmental/plant-covering-materials.htm

https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/growing-hydrangeas-hydrangea-care-guide.htm