Be Fearless & Prune These 7 Plants in May – Here’s EXACTLY How Much to Snip Off Garden Shrubs to Get Way More Flowers

May is the time to prune the early spring-flowering shrubs in your garden. Most deciduous spring-flowering shrubs bloom on stems grown the previous year. So, prune immediately after they’ve finished flowering this year and new stems will have lots of time to grow while the warmer weather’s here. And guess what? Those long, strong stems mean you’ll get maximum flowers next year.

Pruning spring-flowering shrubs is a simple task, even if you’re a beginner gardener. All these plants are vigorous growers so they’ll tolerate less-than-perfect cuts while you learn the pruning mistakes to avoid. You just need to be brave! Everything you need to know about the plants to prune in May is right here, so let’s get cracking.

When Should I Prune Spring-Flowering Shrubs?

All these shrubs will finish flowering in late spring, depending on your USDA zone, and for best results, you need to prune them as soon as the flower show is over. In most zones this will be in May but, in colder zones, could be early June. Do check for any nesting birds first, and wait until after any babies have fledged before pruning if needs be.

What Shrubs Should I Prune in May?

1. Forsythia

Once the wonderfully bright show of vibrant yellow flowers on your Forsythia has faded, it’s time to give it a trim. First, remove any dead, diseased or damaged stems. Next, cut one in five stems from the base of the plant. This seems harsh but if you do this every year, your forsythia shrub will be continually rejuvenated for plenty of flowers. It will prevent the shrub's center from becoming congested, too. Then shorten the rest of the stems by up to a half, cutting to a strong young shoot so you don’t leave any stubby ends.

Do this and next spring, you’ll have a well-shaped shrub that’s smothered in flowers around the base as well as the top of the plant.

2. Mock Orange

Philadelphus puts on one of the most beautifully scented displays in spring, filling gardens with its sweet, citrussy fragrance. When the show is over, a trim will encourage new growth and, as this shrub flowers on old growth, lots of flowers next year. It’s not vital to prune mock orange every year, but doing so will keep it healthy and invigorated.

You can safely remove up a third of the stem length, all over. Philadelphus is a fast grower and, depending on variety, grows around 2 feet a year, so judge how much height to remove after considering whether you want the shrub to be bigger next year, or remain a similar size. Cut stems just above a strong shoot, and remove any dead, diseased or damaged growth as you go.

Next, cut a few stems at ground level to thin out the base, removing up to a fifth of the older, thicker growth. This helps to reduce congestion in the center of the shrub and, over time, ensures main stems aren’t left to become old and unproductive.

Finally, remove about a third of the length of remaining stems, cutting just above a strong side shoot. Think about which side shoot to choose as the new growth will follow in that direction: by selecting an outward-facing shoot, you’ll help your mock orange to grow into a pleasing shape and is another way to reduce congestion.

3. Japanese Kerria

Spring just wouldn’t be spring without the dramatic egg-yolk yellow flowers of Japanese kerria, and a prune when it’s done blooming will ensure another vibrant show next year.

You’ll need to be brave because the best way to prune Kerria japonica for lots of flowers is to remove one in three stems at ground level. Obviously, prioritise getting rid of any dead, diseased or damaged stems, then move on to the oldest stems. This will encourage lots of new canes to shoot up, and these are the ones that will bear the most blooms next year. This is a tough shrub so don’t worry!

Shorten the stems that are left, too, removing around two-thirds of last year’s growth.

4. Weigela

Once you’ve enjoyed the spring carnival of Weigela flowers, it’s time for some tough love to ensure next year’s show is just as dazzling. Depending on the variety, weigela can reach up to 10 feet high and wide, so pruning will also keep this vigorous shrub to a manageable size.

Reduce the length of all the stems by up to a half, cutting just above a strong shoot. If you can, choose a shoot that’s facing outwards as then the new stem will grow in that direction, helping to avoid congestion in the center of your shrub. Remove any dead, diseased or damaged stems you find.

Then cut a fifth of the stems down to ground level, as low as you can go. Choose the oldest, thickest stems to remove and this will keep your Weigela invigorated and flowering well.

5. Flowering Quince

If you’re growing an ornamental quince for its flowers, pruning once its pretty petals have faded in May will ensure a great display the following year. Whether your shrub is Chaenomeles japonica (Japanese quince), C. speciosa (Chinese) or the hybrid Chaenomeles x superba that’s a cross between the two, it needs pruning in the same way.

All flower on old wood, so a trim now will encourage plenty of strong stems for lots of blooms next spring. Shorten all the side shoots to 2–4 buds to leave a permanent framework of branches, and remove any dead, diseased or damaged growth. Flowering quince has thorns so do wear protective gauntlet gloves such as these thornproof gloves from Amazon.

It’s also a smart move to reduce congestion by taking out a fifth of older stems at ground level. There’s no need to do this every year with C. speciosa but don’t skip this step with C. japonica as it’s far more dense and twiggy. Snip off any suckers you spot at ground level, too.

6. Spring-Flowering Spirea

If you have a Spiraea (commonly spelt 'spirea') that flowers in spring, prune it after it’s finished blooming. Some spiraea shrubs bloom in summer though, so leave these well alone or you’ll chop off this year’s flowers!

Trim the flowered shoots, cutting just above a pair of buds, to create a pleasing shape. A light trim is usually all that’s needed but, if you want to reduce the size of your spirea, you can safely chop off up to a third of the stem length. Older shrubs have a tendency to become very congested in their centers and only put on fresh growth around the outside of the base – if this is happening to your spirea, cut a fifth of the oldest central stems to the ground to encourage it to reshoot.

7. Flowering Currant

You don’t have to prune Ribes sanguineum (flowering currant), but giving it a trim will keep your shrub healthy, improve its shape and, as it blooms on stems grown the previous year, bring lots more flowers next spring. And these rosy-red tubular blooms are such a treat, it’s good to have as many as possible!

Prune as soon as flowers have faded, and cut all stems back by a third. Always cut just above a strong stem as this is where the new growth will come from. Remove any dead, diseased or damaged stems as you go. Snipping stems will of course mean you get fewer ornamental berries so your shrub will be fine if left to grow larger but there’s a happy balance to be struck in growing maximum food for your backyard birds long-term: a trim now will reduce this year’s berries but it will stimulate new growth for lots of flowers, and therefore berries, next year.

Finally, remove one in five stems at ground level to reduce congestion and keep the plant invigorated. Look for the oldest, thickest stems to remove – these are usually a darker color. Job done!

What Pruning Tools Are Best to Use?

Many of these shrubs have woody stems, so the key is to have the right pruning tools to make the job easy, not just for you but for the plant, too. If you’re able to easily slice through a stem, you make a clean cut that is quick to heal. If you struggle, you’re likely crushing and tearing the stem, making a ragged cut that takes more time and energy to heal. Pruning shouldn’t be hard work – if it is, you’re using the wrong tool!

For stems up to ¾ inch in diameter, a pair of hand pruners is best. As a general rule, bypass pruners make cleaner, healthier cuts than anvil hand pruners, as long as the stem is soft enough to slice easily. The blades of bypass pruners such as Fiskars Bypass Pruning Shears, available from Amazon, pass each other, the top blade doing the cutting while the bottom blade holds the stem in place. Anvil pruners, however, work like a knife against a chopping board, which can crush softer stems. But, when you’re dealing with old, woody stems which are tough to cut through, anvil pruning shears are better as they’re more powerful. Many designs, such as these TGF Anvil Pruners available from Amazon, have a ratcheting motion which brings you even more power.

Another option for tough, woody stems is a pair of long-handled loppers such as Fiskar’s Bypass Loppers, available from Amazon. The handle length gives you more leverage, affording more power to those bypass blades. Loppers are also great for old, woody stems up to 1½ inches in diameter, and are especially handy for removing old stems at the base of a plant.

For stems bigger than 1½ inches in diameter, you should be using a pruning saw such as a Rexbeti Folding Saw, available from Amazon. This makes light work of cutting through stems up to 5 inches in diameter.

Do make sure your pruner or lopper blades are sharp before you start cutting. Simply run a sharpening tool such as this pocket-sized tool from Amazon along the blade to create a fresh, sharp edge, and resharpen as you prune.

Should I Feed & Water After Pruning?

After pruning your shrub, give it a thorough water to help it cope with the stress of healing its stems. This is a good time to feed your plant, too. Either use a balanced slow-release fertilizer such as Miracle-Gro Shake ’n Feed For Flowering Trees and Shrubs, available from Amazon, or spread a 2-inch layer of mulch, such as homemade compost or Back to the Roots organic Mulch, also available from Amazon, around the base, keeping it away from stems.