6 Shrubs You Should Never Prune in Spring, According to Horticulturists Time to put the pruners away. Close Credit: Christophe Lehenaff / GETTY IMAGES The best time to prune most shrubs is in the winter when the plants are dormant, so you can better see their shape. Which means there are many that you should avoid pruning in the spring—with a few exceptions, like forsythia and a few other spring-flowering varieties. So, how do you know which shrubs to prune when? It's always best to check with a local cooperative extension or a gardening professional before you try your hand at pruning. But in the meantime, we chatted with horticulturists about which shrubs you should never trim in the spring. Laura Irish-Hanson, extension horticulture educator at the department of agricultural and natural resource systems, University of Minnesota Extension David Hillock, consumer horticulturist and state coordinator of the Oklahoma State University Extension's master gardener volunteer program 10 Fast-Growing Shrubs to Plant in Your Garden 01 of 06 Virginia Sweetspire Credit: Catherine McQueen / Getty Images Virginia Sweetspire (Itea virginica) is a deciduous shrub with long, thin flower spires at the end of its branches. David Hillock, horticulturist at the Oklahoma State University Extension, recommends keeping the shrub in partial shade and pruning it only after it's done blooming—usually by the end of June. 02 of 06 Some Hydrangeas Credit: Getty Images Not all hydrangeas have the same blooming habits, and some will flower only on new wood. However, bigleaf hydrangea, one of the most popular varieties, blooms on old wood, which means you should wait until after spring to prune. "This is one you would prune in late fall or during winter," says Hillock. For smooth hydrangea, it may be a better idea to let the shrub grow out a season or two before pruning it at all, since this variety blooms on new wood. How to Prune Every Type of Hydrangea (and When to Do It) 03 of 06 Lilacs Credit: Elena Popova / Getty Images Lilacs (Syringa) are a favorite spring-blooming shrub, and are beloved for their fragrant, white and purple flowers. The blooms can last for up to two weeks; the shrub is also a favorite nesting spot for birds. The only downside? Lilacs are susceptible to disease. "They usually don't kill the plant, but they can defoliate it," says Laura Irish-Hanson, horticulture educator at the University of Minnesota Extension. If you start to trim back your lilac bush too much in the spring, you can create even more stress for the plant. 04 of 06 Elderberries Credit: 2ndLookGraphics/Getty This native shrub (Sambucus canadensis) is best pruned in late winter, and maybe very early spring. After that, let them be. "Once they're waking up and out of dormancy, you should leave them alone, unless there's damage," says Irish-Hanson. For example, if a storm hurts the shrub, then making a clean cut is always the best choice. Elderberries will bloom all the way through summer if you don't trim them prematurely. 05 of 06 Bush Cherries Credit: Getty / Naturfoto Hanal A hybrid cherry developed in Canada, bush cherries (Prunus) are known for their hardiness. However, like cherry trees, you don't want to trim a cherry bush in the spring, as you'll lose the shrub's blossoms and fruit, and possibly open it up to disease. Irish-Hanson recommends pruning in winter when the plant is still dormant. 06 of 06 Azaleas Credit: Catherine McQueen / Getty Images The type of azalea you have will determine when you prune them. Deciduous azaleas, for example, can bloom through October. There are also various hybrids that don't just bloom in spring. "There are some ever-bloomers that bloom pretty much all season long," adds Hillock. However, if you're growing a variety that blooms in the spring, then never prune the azaleas in early spring. Doing so can remove the flower buds before they bloom. Explore more: Garden Landscaping