Are you one of those homeowners who never does ANY pruning? Well, you have lots of company. But really, it’s almost impossible to kill these plants by some pruning error and VERY likely you’ll improve its health and appearance, so give it a go! These are all plants I grow myself, but I’ve researched the pruning advice just in case, and here’s the best I found online.
I take issue with only one bit of Lee’s advice and that’s about Spirea japonica, which he says to prune in late winter/early spring – but for most of them, that would remove this year’s blooms. I suggest Googling the exact variety you have and the word "prune" to find out when to prune, or just do it soon after blooming, no matter which type you have (that’s always safer, anyway).
Now’s the best time to prune deciduous trees and shrubs except those that flower in the spring. If you like the size and shape just fine, at least remove these branches:
- dead ones
- diseased branches
- branches that cross other branches (literally touching, rubbing)
- branches that grow toward the center of the shrub, causing crowding
- branches that are thinner than a pencil or diseased
- suckers and water sprouts – that mess of shoots around the base of the shrub and the branches that shoot straight up at a 90-degree angle from a larger branch
Here’s a Fine Gardening article about pruning wisteria – both in the summer and winter.
Same basics here about removing dead, diseased, crossing, very thin or spindley branches first. But also the old and unproductive branches (they’re darker in color and thicker). Then cut back last year’s growth by 1/3 to 1/2. Cut just above outward-facing branches. (For more on this concept of outward-facing, follow the links above to the Basics article and the Where to cut video).
And I found a video by the rose expert at the Brooklyn Botanic Garden about late winter pruning of shrub roses. I like how bold he is, encouraging us to remove most of the plant, but even a too-dark video can show what healthy wood looks like. For climbers, see how to prune climbing roses by Fine Gardening.
Fine Gardening also has a great article on pruning crape myrtles.
In general, hydrangeas are best planted where they can grow to their full size, and don’t need much pruning – removal of dead flowers (actually that’s deadheading, right?). If you DO prune to reduce size, they quickly return to full size anyway. Then older shrubs (5 years or more) benefit from having a third of their stems – the oldest ones – removed to the ground every year, and now’s a fine time to do that.
Typically the pruning advice for big-leaf types (H. macrophylla) that bloom pink, blue, or purple (H.macrophylla) is to prune after flowering, but the flowers look good in my Zone 7 for 5 months or more, so again, it’s better not prune them at all, except to remove dead branches and to renew older shrubs.
H. paniculatas (like ‘Tardiva’) will have larger flowers on stronger stems if you prune the main branches to within 2 buds of their bases in mid-spring.
And for H. paniculata, H. arborescens (like ‘PeeGee’) and H. quercifolia (oakleaf, like ‘Snow Queen’), now’s the time to remove dead stems. Sources recommend that for bigger blooms, cut way back, even all the way to the ground. OR to avoid flopping, leave a framework of branches 18 to 24 inches tall, and the blooms will be smaller but they’re less likely to flop, and there should be more of them.
Treat them as a perennial, cutting back to 1-2 inches in mid to late spring.
Buddleias need to be pruned HARD annually otherwise they’ll become leggy with all the flowers at the end of tall stems. In a small garden, cut them back close to the ground in the spring. If they have plenty of space, you could instead cut back each stem to within 2 buds of the stump of old wood.
Hack ‘em back to 6-12 inches now, before the new growth starts and you’ll have a mess on your hands trying to remove the old without removing the new
Most bloom early in the season on buds that formed the previous year, so wait til after they bloom to prune. But even these early bloomers could be thinned now if they’re old and too crowded (by removing a third of the stems to the ground.) Same goes for branches that are in your way and dead stems – they might as well go now. If you you’re not sure which stems are dead, wait til mid-spring, and you’ll know the dead ones because they don’t leaf out.