The Best Time to Prune Nandinas

Nandina (Nandina domestica) is also known as heavenly bamboo, although it has no relation to the bamboo plant. It takes the nickname from the fact that its foliage bears an uncanny resemblance to that of bamboo plants. Found in USDA plant hardiness zones 6 through 9, nandina is a woody shrub with year-round interest. It bears flowers in the spring and berries in the fall when its foliage turns red, gold and orange. In warmer climates, it is evergreen through the winter. One of the most important aspects of nandina care is annual pruning—which is best done in late winter or very early spring.

nandina domestica background
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Nandina foliage and berries provide brightly colored fall and winter interest.

When to Prune

Nandina produces flowers in late spring or summer, which then give way to attractive green berries. These ripen to a striking red color in autumn and remain on the plant throughout fall and sometimes through winter. While spring pruning is appropriate for many shrubs, if you prune the nandina too late in the spring, you run the risk of not having berries the following season. The ideal time to prune is in late winter or early spring.

Pruning Tools

The act of pruning a plant causes wounds, and the best way to minimize wounding is by using the right tools and keeping them sharp. Two types of tools are used to prune the nandina. Use bypass pruning shears to cut branches and shoots that measure 3/4 inches in diameter and smaller. Bypass pruners, while more expensive than anvil-type pruners, make a cleaner cut. For growth measuring up to 1 3/4 inches in diameter use lopping shears.

Strategy

When you prune the nandina, you set the stage for the following season's growth. These are vigorous growers, so aggressive yearly pruning is in order.

  1. Prune one-third of the stems, spaced randomly around the nandina, all the way back to the soil level.
  2. Prune another one-third of the stems down to one-half the shrub's height—these stems will sprout new growth and fill in the middle of the shrub.
  3. Allow the final third of the stems to remain unpruned. This staggered effect will show off next season's flowers and berries.

After-Pruning Care

After pruning is a good time to fertilize the nandina to get it ready for the upcoming season. Use a 10-10-10 water-soluble fertilizer </ahref="http:>at half strength or apply a rhododendron and azalea fertilizer, which is high in acid. You can also use a granular fertilizer according to the rate listed on the package for the size of your nandina. Sprinkle the fertilizer over the soil, starting 6 inches away from the shrub's base, and use a rake to spread it out 1 foot beyond the dripline. Water to a depth of 8 inches, and lay down a fresh layer of mulch if you use it.