March Is Your Last Chance to Prune These 8 Plants – Miss the Window and You’ll Get Fewer Flowers

Many plants are best pruned at the end of winter or in very early spring, before they break dormancy and after the risk of a lot of cold weather. Depending on where you live and garden, March might be the last chance to do this crucial task that promotes healthy new growth and flowering and maintains a plant’s size and shape.

Before you get started, be sure you know the pruning basics. You also need to know which plants are best pruned this time of year.

Some should be left for later in the summer or fall, but these are the ones to tackle now, before it’s too late.

Pruning Tips

First, let’s go over a few basics of pruning. While some plants have specific, unique needs, these guidelines are a good general blueprint for all pruning and trimming:

• Use clean, sharp pruners or shears every time you prune. Our team of gardening experts recommend these bypass pruners from Fiskars for clean and easy cuts. Dull or dirty tools can damage branches and introduce disease.
• Remove damaged or diseased branches first. You can actually remove these any time of year.
• Remove suckers.
• Once damaged, branches and suckers are gone, you can do the bulk of the pruning work. Remove no more than one-quarter to one-third of the plant. Prune for shape and size, to eliminate crossed branches, and to let more light into the interior of the plant.
• Make cuts at a 45-degree angle and just above nodes. If you cut at an outward-facing node, new growth will also face outward. Cut at inward-facing nodes for more inward growth.

Plants to Prune in March

In general, you should prune these plants before they break dormancy and start leafing out. If you live in a warmer climate, it might be best to wait until next year, but many gardeners can still do this last-minute chore in March. These are some plants to focus on:

1. Smooth and Panicle Hydrangeas

Hydrangeas are incredibly popular landscaping shrubs for their big, attractive blooms that last throughout the summer and into fall. Only smooth and panicle types should be pruned in early spring. Double check what type of hydrangea you have before you start trimming. Bigleaf and oakleaf hydrangeas bloom on old wood. Trim them now, and you’ll reduce flowering.

For your panicle and smooth hydrangeas, which bloom on new wood, March is a good time to shape them and promote strong new growth. The smooth types grow readily, so you can be more aggressive with pruning. Use a lighter touch with panicles. For both, trim out problem branches and do some light shaping or size management.

2. Butterfly Bush

Butterfly bush blooms in summer with lance-shaped panicles dense with purple flowers. They attract pollinators, like butterflies and bees, to your garden. Like the above hydrangeas, butterfly bush blooms on new wood, so an early spring trim is a good time for shaping, size management, and encouraging fresh growth and bountiful flowers.

Butterfly bush tends to get leggy and overgrown, so they can withstand a fairly hard prune in March. You can cut it all the way back to a foot or two off the ground and still get excellent growth in the coming months. As an aggressive grower, it’s also a good idea to prune butterfly bush's spent flowers later in the summer. This will prevent the spread of seeds and new bushes that can get out of control.

3. Roses

Another good task to tackle now is pruning your rose bush. Timing is important, though. March works for gardeners in colder climates. You don’t want there to be a lot of cold weather to come, but you also can’t wait until the rose bushes have put out a lot of new growth.

If the timing is right in your garden, trim out dead or damaged branches, any branches that cross each other and are at risk of rubbing and creating wounds, and some of the oldest, woodiest growth. This spring pruning shouldn’t be heavy. Use a light hand and remove the most problematic parts of the bush.

4. Dogwoods

March is the perfect time to prune dogwood trees and shrubs. Twig dogwoods are the dogwood shrubs with bright red or yellow stems that provide great color and visual interest in winter. You want to keep them intact throughout the dormant season, so you can enjoy the color, so early spring is a good time to start pruning.

Dogwood shrubs develop their best colors on new growth. As stems age, the color dulls to gray. To promote new, vibrant color, trim the stems all the way to the ground, this is also called rejuvenation pruning. Just be sure to wait to do this annual chore until the shrub has been in the ground long enough to establish strong roots, about two to three years.

Your flowering dogwoods, small trees, can also be pruned now if they are still dormant. If a dogwood tree has already come out of dormancy, it’s a good idea to leave it alone. It will bleed a lot of sap that attracts pests. If it is still dormant, you can do some light pruning in March.

5. Rose of Sharon

Rose of Sharon is a large, tree-like shrub that can grow quite tall and that blooms prolifically in summer and into fall. The flowers form on new wood, meaning late winter and early spring are the right times to prune rose of Sharon. Fortunately, it doesn’t need a lot of trimming, but some light cuts can help you shape the shrub and manage its size.

Timing is important here. March is the right time to trim your rose of Sharon if it hasn’t developed much new growth yet. If you’re in a warmer climate, and it’s growing new branches and buds, it’s too late. Prune to remove damaged, crossing, or diseased branches. Shape the shrub as you see fit. Many gardeners like to trim the rose of Sharon into a narrow pillar shape. For older shrubs, prune out some of the central branches to open up the interior and allow for air and light to penetrate.

6. Broadleaf Evergreens

Late winter and early spring are the ideal times to trim and prune many of your broadleaf evergreens. This includes boxwood, holly, and abelia. If any of your plants in this category put out attractive flowers in spring, you can wait until after they’ve bloomed and faded.

Most broadleaf evergreens benefit from light trimming at this time of year. Manage any damaged or diseased branches, but also clear a path for light and air to the interior. Follow branches down to a larger stem to make a cut. This will open up the inside of the plant, allowing for denser growth. Once it’s dense and healthy, you can trim the outside of the plant to shape it. A cordless, handheld shrub trimmer like this one from Amazon makes smooth shaping easy.

7. Russian Sage

Russian sage is a semi-woody perennial that provides an abundance of glorious purple color in summer. It’s a great filler plant in beds, but it can become overly woody, leggy, and floppy. Pruning it regularly keeps it healthy and full and also promotes a maximum of flowers.

March is an ideal time for this task, just as the perennial is developing early growth. Trimming Russian sage too early can stimulate growth too soon before it’s safe from winter damage. Give your plant a heavy pruning, cutting stems down to between 8 and 18 inches (20 to 46 cm) from the ground. It not only withstands this heavy trim but will reward you later with a dense, compact shrub with an abundance of flowers.

8. Wisteria

Wisteria is a beautiful vine that blooms with hanging clusters of purple flowers like grapes. They look nice growing over an arbor or pergola, but can also be trimmed into a small, weeping tree shape. The only issue with wisteria is that it grows quickly and aggressively. Heavy, regular pruning is a must to manage this robust vine.

If you have wisteria, your first of two pruning sessions each year should take place in late winter or early spring. March isn’t too late in most places. Before the leaves emerge, you have a good sense of the shape and size of the vine. Use this to your advantage to make strategic cuts, keeping in mind that it’s nearly impossible to cut too much. In addition to shaping, trim back some of the lateral vines. Winter pruning wisteria will stimulate more flower production later.

Essential Pruning Tools

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