Hydrangea Oakleaf – Pruning, Winter Care and Fertilizing

Fall Color

This is a slow growing plant that will need a minimal amount of pruning. Pruning, however, can be very important to the overall look of the plant. Only prune in early spring before the plant leafs out. Crossing, badly formed or damaged branches should be removed back to a main branch. This plant grows and develops best in acidic soil. Most of the soil, all of the rainwater and all of the ground water in southeastern Wisconsin is basic or alkaline. Therefore, for some plants to thrive, they need to have special care.

Initially, the soil the plant is installed into should be amended to make it more acidic and to increase the amount of organic matter in the soil. Over time, the soils acidity should be supplemented with an acid-based fertilizer. A liquid fertilizer, like Miracid works well. This liquid fertilizer is mixed with water and applied the same as you would water the plant (see product for specific details). This type of fertilization should be done three or four times per year, starting in April and ending by mid-July. Soil can also be acidified with soil sulfur, aluminum sulfate or cotton seed meal, however, these products will not fertilize the plant. Mulch is also important to acid loving plants. A 2-4″ thickness of bark or needle mulch should surround the plant at least as far out as its drip line.

Surprisingly this shrub is susceptible to rabbit  damage, one of the only hydrangea that is. If rabbit problems are found, you can protected them with a fence formed with hardware cloth (looks like chicken wire , with small square holes). The plant is tied in, then a section of hardware cloth is put around the outside. The base of the cloth is buried in soil or mulch. This protection is put on in late November and removed in mid April.