Plants To Prune In August: 8 Garden Favorites

August is an excellent time to prune rambling roses, wisteria, honeysuckle, hardy geraniums, catmint, summer-flowering spirea, escallonia, and tired perennials. A light, timely trim improves shape, encourages repeat bloom where possible, and prevents energetic plants from treating your back yard as a personal expansion project.

The aim is not to go berserk with the pruners. In the heat of late summer, clean, selective cuts are far more useful than heroic hacking, particularly in temperate zones where plants need time to recover before fall.

Once the trimmings are gathered, there is still plenty of opportunity in what to plant in August to fill a gap, refresh a container, or make plans for the cooler months ahead.

Start With Clean, Sharp Tools

Before approaching any plant with intent, give your pruning tools a moment of attention. Blunt blades crush stems rather than cutting them cleanly, which is rather like trying to slice a tomato with a deck chair.

For everyday jobs, I reach for bypass secateurs such as these Okatsune secateurs from Amazon. For mature wood, Corona loppers from Amazon give you reach and leverage without requiring the upper-body strength of a medieval blacksmith. A Silky pruning saw from Amazon is useful for the occasional old cane or branch that has become too stout for pruners.

Wipe blades with rubbing alcohol between plants, especially if anything looks diseased. And wear gloves: roses, in particular, have an unnerving ability to locate the one patch of skin you neglected to cover.

Tidy Rambling Roses After Their Main Display

Rosa 'Westerland' blooming with orange flowers

Rambling roses make a spectacular early-summer performance, then seem to retire backstage in a tangle of long canes and fallen petals. August is a good moment to restore a little order once their main flush has finished.

Remove a few of the oldest, flowered canes right down at the base, then tie in vigorous new stems to wires or a support. These younger canes are the ones that will carry next year’s flowers.

Shorten unruly side shoots to around two or three leaves from the main framework, but resist the temptation to shear everything into a neat dome. A rambler should look generous and romantic, not like a green pom-pom with thorns.

I have learned, usually while standing on a ladder with a rose hooked into my sweater, that tying in comes before cutting. You can see the plant’s true structure only once its best new growth has been gently persuaded into place. Climbing plants don’t always have to grow up trellis, and our guide will give you lots of inspirational alternatives.

Put Wisteria Back In Its Place

Wisteria (Wisteria sinensis and Wisteria floribunda) is glorious in bloom and entirely without manners afterward. Given a summer, it will explore gutters, windows, rooflines, and potentially your neighbor’s opinions on property boundaries.

In August, shorten this season’s long, whippy shoots to five or six leaves from their base. This neatens the plant, lets in more sun, and helps encourage the formation of flower buds for next year. Keep the permanent framework intact; it is the elegant skeleton on which the whole theatrical display depends.

Use pruning shears for pencil-thick shoots and a pruning saw only for genuinely old wood. Never make every cut identical, as though you are trimming a hedge in a municipal parking lot.

Follow each shoot back to a sensible bud or side branch. If you are adding a climber to a fence or pergola, our advice on what to do with wisteria will save a great deal of future negotiation.

Refresh Catmint For A Second, Softer Flush

Purple flowers of a catmint plant in a garden

Catmint (Nepeta spp.) is one of the most forgiving perennials in the summer garden. Its first flowering often ends in a faintly melancholy puddle of gray-green stems and spent blue flowers, as though it has been caught in a rainstorm after a very good party.

Shear the whole clump back by around one-third to one-half after the first major bloom. Make a rounded cut, leaving healthy foliage and a few inches of stem above the crown. Water afterward if conditions are dry, and you may be rewarded with a fresh, more compact flowering later in the season.

This is a very satisfying job: rapid, low-risk, and instantly transformative. In Zones 3–8, catmint is generally tough enough to shrug off the haircut and get on with things. It is also among the most generous plants for pollinators, so leave any flowers that are still buzzing with activity until their visitors have moved on.

Cut Back Hardy Geraniums That Have Gone Flat

Hardy geraniums make excellent ground cover plants

Hardy geraniums, not to be confused with annual pelargoniums, often produce a long and lovely early-summer display before splaying across neighboring plants with the languid confidence of a guest who has stayed through breakfast.

By August, many varieties benefit from a firm cutback. Remove the tired flower stems and trim the foliage to a few inches above the soil, taking care not to damage the crown. In warm, dry regions, water deeply afterward; in cooler temperate areas, the plant will often respond with handsome fresh leaves and, in some cases, a second scattering of bloom.

I tend to tackle hardy geraniums in stages, leaving any clumps that still look lively and cutting back only the ones that have become floppy. It keeps the border from briefly resembling a freshly mown lawn. Pair the revived foliage with late performers such as salvias or rudbeckias for a sunning late summer evening display.

What to Shop

Deadhead And Lightly Shape Summer Spirea

Japanese spirea (Spiraea japonica) is one of those useful flowering shrubs that will work remarkably hard if you meet it halfway. Once the flat pink or white flower clusters have faded, deadhead them promptly by cutting back to a healthy set of leaves.

For a tired, straggly plant, lightly shorten the outer stems to restore a neat outline, but do not reduce it savagely in August. This is a grooming session, not a demolition project. The goal is to encourage a possible repeat bloom and keep the shrub looking intentional through fall.

Spirea is hardy in many temperate gardens, commonly Zones 4–8, and handles the changeable conditions of late summer with admirable composure. I particularly like it near ornamental grasses, where its tidy mounds provide a useful contrast. A few minutes spent deadheading is one of those summer gardening jobs that makes the whole border look more awake.

Keep Honeysuckle Flowering Where You Can

Honeysuckle (Lonicera spp.) can be an enchanting climber: scented, generous, and beloved by hummingbirds and moths. It can also, when neglected, become a knot of old stems that appears to have been assembled by a determined spider.

For repeat-flowering types, remove spent blooms and shorten the flowering side shoots lightly after the main flush. If there are dead, weak, or crossing stems, take those out completely. Keep the principal stems tied to their support, then work slowly from the outside in; this prevents the kind of accidental pruning that leaves you holding the only branch that mattered.

The exact timing varies by species and climate, so avoid a major renovation in August. In Zones 4–9, light summer shaping is usually enough to maintain a healthy, flowering plant. For a little more fragrance near seating areas, climbing plants for pots offer plenty of companions for honeysuckle.

Neaten Escallonia After Flowering

An escallonia shrub is covered in pink flowers in the summer

Escallonia is an excellent evergreen or semi-evergreen shrub for mild, coastal, or sheltered gardens, with glossy leaves and clusters of pink, red, or white flowers. Once flowering finishes in late summer, a light trim prevents it becoming leggy and keeps hedges pleasingly dense.

Use hand pruners rather than hedge shears if possible such as these secateurs from Amazon, cutting individual shoots back to a side branch. It takes longer, yes, but the result looks natural and allows light into the plant. If yours is used as a hedge, a restrained clip is perfectly acceptable; just avoid cutting back into old, leafless wood, which may not regenerate willingly.

Escallonia is best suited to milder temperate conditions, typically Zones 7–9, and deserves a position out of harsh winter wind. It is especially effective in a low-maintenance garden with evergreen structure, where its foliage quietly earns its keep all year.

Give Faded Salvias A Second Chance

Savlia amistad with a hummingbird feeding on its nectar

Perennial salvias are the reliable extroverts of the August border. They flower generously, attract pollinators in droves, and then, after the first big display, look a little as if they have forgotten why they came into the room.

Snip away spent flower spikes to just above a strong pair of leaves, working through the plant as flowers fade. I like using a pair of Okatsune snips from Amazon to get into tight spaces. If most spikes are finished, cut the entire plant back by roughly one-third, keeping plenty of leafy growth below the cuts. Water well in dry weather, and a second flush is often not far behind.

For hardy varieties in Zones 4–9, this is a simple route to a longer season of color. I favor doing it in the cool of morning, preferably with coffee nearby, because a salvia border full of bees is not an activity to rush. The same thoughtful approach works for the plants to deadhead in August, where a small cut can keep flowers coming until fall.

The best August pruning is selective, calm, and based on what is actually in front of you. Remove what has flowered, flopped, crossed, or outgrown its allotted space; leave healthy growth to capture the last generous weeks of summer.

A sharpened blade, good gloves, and a little botanical restraint will take you a long way. Most plants do not need a dramatic intervention. They simply need you to look closely, make a few confident cuts, and then stand back long enough to admire the improvement.

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