8 Plants That Need To Be Pruned In Spring (And 7 That Don't)

As you start to notice the warm and verdant hints of spring's arrival, it's tempting to grab our garden tools and head outside to tackle the first round of cleanup. When it comes to tidying your plants, however, you'll want to be careful about how and when you prune them. Some plants will benefit from a spring trim, like butterfly bush and hydrangea, but clematis and azalea could be damaged by cutting so close to bloom time.

In general, most plants should be pruned just after they've finished flowering — late summer or fall. But some plants benefit from leaving their old growth to protect them over the winter. These plants tend to sprout "new wood" for their spring growth, whereas the others use their "old wood" to set their flower buds on the stem before winter begins. Old wood plants could be stunted by spring pruning and could remove its future blooms. Although it seems counterintuitive, the new wood plants benefit greatly from spring pruning, as cutting them back actually stimulates growth. In any event, if you notice dead or diseased material on your plants, cut it out immediately, regardless of season.

Any time you're pruning or trimming plants, be sure your tools are sharp and sanitized so they're making clean cuts all the way through the branch. Also, try to cut as close to a 45-degree angle as possible to help the plant heal faster. After pruning, put down a layer of compost or other fertilizer to send your plants into their growing season with the nutrients they need. Now, what else needs snipping?

Butterfly bush (Buddleia spp.) grows in zones 5 through 9 and depends on a dramatic annual spring pruning to guarantee good flowering. Using a pruning process called rejuvenation, every branch is cut back to a length of about 1 foot. It sounds extreme, but anything less will result in a leggy plant and fewer flowers during blooming time. Each remaining piece also needs to have dead stems removed all the way down to the plant's base. Don't be alarmed by your plant's barren new look; it will regrow quickly. 

Like many of the spring-flowering shrubs, rhododendrons also don't require much maintenance in the way of pruning — this include the most popular type of rhododendron, azaleas. When they do outgrow their confines, it's best to wait until summer flowering has peaked. With this type of evergreen shrub, the only pruning that usually needs to happen is removal of dead or diseased shoots that can appear each spring. If you see these, it's okay to remove them at any time.

In general, you don't need to prune a rose of Sharon (Hibiscus syriacus)​ much. This hardy tree-like shrub puts out trumpet-shaped flowers from summer to early fall. While rose of Sharon needs little pruning, some gardeners do it for uniform shape or to remove dead and damaged branches. If you find any dead stems, cut them all the way down to the base. If only damaged, cut just below the damaged area so they can regrow. An annual pruning won't harm your plant, but it will mean fewer (but larger) flowers on each branch. 

This member of the honeysuckle family (Weigela florida) is better left to prune later in the growing season just after it's finished flowering, generally midsummer.  This is because the new flowers will then set themselves on the old wood to bloom next spring. If your weigela plant has matured to a point that it needs some reshaping, it's best to remove the old, interior branches in late winter.

Lavender requires regular pruning to maintain healthy growth and to help it keep its shape. It can be pruned in summer once the fragrant flowers have died off or in early spring before new growth begins. If you wait until spring, it can help rid the plant of dead foliage and stimulate new growth. When you prune, try to stay at least two inches above the woody base and shape the plant into a rounded mound. An added bonus to pruning lavender is how amazing your garden will smell!

This fragrant climber (hopefully a native variety and not an invasive one) is a delight in the summer garden. It doesn't need much coaxing to grow. You'll need to do some casual pruning, however, to help it keep its shape or meander in a different direction. Note what variety you have to know when to prune. If you have an early-flowering honeysuckle, prune just after flowering has finished in the summertime. Late-flowering varieties should be left alone. If a trim is absolutely needed, do it as early in the growing season as possible — even spring!

Ornamental grasses go dormant when the cold weather hits. But don't cut them back before winter. Instead of pulling out the shears and lopping them off, let them add texture and movement to your winter yard and provide seeds for birds looking for meals in hard times. When spring rolls around, cut them back to a height of about 3 to 6 inches for small grasses or about 10 inches for taller ones. Prune anytime after the grasses are brown and dormant, but do it by mid-spring before they green up and start growing again.

These beautiful bright yellow shocks make a strong appearance in the spring, but can become a bit tall and misshapen over time. If you find yours in need of a trim, it's best to time your removal efforts for early summer when the flowering has stopped. This will prevent any cutting of next year's buds that will grow on the old wood. To maintain a healthy flowering next spring, trim no later than late July.

Dogwoods (Cornus spp.) don't depend on an annual pruning, but can benefit if they've grown too large or have damaged or diseased limbs. However, if you prune them at the wrong time, the living branches will bleed sap. Therefore, the tree should be dormant when you prune, which will help it heal faster. For best results, simply trim off dead or damaged branches or any overgrowth to reduce the size of the plant. If the tree has any suckers, those should be removed as well.

Put down the gardening shears and step away from the camellias. Generally speaking, these plants don't need pruning unless they're diseased or they've outgrown their prescribed area. Any time you cut down a camellia bush, you risk disrupting the blooming process for multiple seasons. If you need to cut your camellias back, do so just as they've finished flowering — usually early summer.

The crepe myrtle (Lagerstroemia indica) is a multi-trunked blooming shrub or tree. Unfortunately, these beautiful plants tend to be over-pruned. They may not actually need any pruning at all, but if you need to trim them back, do it when they're young and can be still be shaped to your liking. The prime time to prune your crepe myrtle tree is in late winter or early spring before any new growth has begun. This plant does not need to be "topped," where all the branches are sawed off at around 5 feet high — which will result in uneven regrowth and poor health for a crepe myrtle.

Wait until early summer to prune your lilacs, just after the beautiful and fragrant flower bursts have faded. The twice-blooming varieties also benefit from an early summer trim so the fall blooms come in fuller and heartier. If you wait any later, you could damage next year's buds. If you want to ensure next spring's flowers, don't prune after the month of July.

Evergreens don't often need care unless they're damaged, diseased, or growing too large. And since evergreens are always, well, green, it's hard to know when to prune. Because this category of trees is broad, so are pruning recommendations. Pine trees are best to prune in early spring just as new growth is forming. Arborvitae, hemlocks, and yews, however, can be shorn in early spring or summer regardless of new growth. Spruce and fir trees should be trimmed back in late winter or early spring. Junipers can be trimmed a little later, in mid- to late-spring.

This one comes with a caveat. Whether these hearty vines are spreading or climbing, clematis come in three types and that will determine what kind of pruning needs they have. Group 1 sets its flowers on old wood and requires little to no pruning. Group 2 bloom on both old and new wood and mild pruning for shaping only can take place in early spring before blooming. Group 3 is new wood clematis and these bloom much later in the season. They should be cut back extensively in late winter.

This category is also a little more complex. Some hydrangeas that grow need a spring trim, while others don't. The panicle hydrangea (Hydrangea paniculata) and the smooth hydrangea (Hydrangea arborescens) both benefit from being left alone over winter and trimmed back in the spring. The big leaf hydrangea (Hydrangea macrophylla), however, should be pruned in the summer just as soon as it's finished blooming. That's because this variety produces next year's buds on its stems before heading into the winter. Oakleaf hydrangeas (Hydrangea quercifolia) should never be pruned in the springtime.