Summer pruning can help certain plants stay compact, rebloom, or push out new shoots. But beware: pruning in summer does not mean cutting every plant indiscriminately. A too-severe intervention, performed during a heat wave or drought, can instead leave them more vulnerable.
Lavender, mock orange, wisteria, and aromatic herbs… Here are the plants that appreciate summer pruning and the precautions to take to protect their health as well as the garden’s biodiversity.
Which plants can be pruned in summer?
Not all plants respond to summer pruning in the same way. Some respond well to a prune after flowering. Others simply need cleaning up or a light trim.
Flowering plants and shrubs to prune in summer
Several flowering plants can be maintained during the summer. The intervention should, however, stay appropriate to their flowering cycle.
- Lavender is pruned after flowering, typically between July and September. Remove spent flower spikes and lightly shorten the foliage, never cutting into old wood.
- Mock orange can be pruned right after flowering. On an established specimen, remove some of the oldest branches at their base to encourage new flowering shoots.
- Perennial geraniums can be cut back after their main flowering. They may produce a fresh flush of foliage and some flowers. For pelargoniums in pots, simply remove spent flowers regularly.
- Viburnum can be pruned after flowering if needed. The exact timing depends on the species cultivated.
- Forsythia should ideally be pruned just after spring flowering. In mid-summer, only remove dead wood or damaged branches.
- Campanula can have spent flowers removed to extend blooming and limit self-seeding.
- Small-leaved sage tolerates a light prune after the first wave of flowers. However, avoid heavy cutting during extreme heat.
The right move
You can leave a few spent blooms to go to seed. They will feed birds and provide shelter to many insects during the winter.
Aromatic herbs to cut back regularly
In the vegetable garden or on the balcony, regular harvests keep many aromatic herbs vigorous. You can pinch or shorten mint, chives, basil, oregano, or lemon balm.
Remove diseased leaves and completely dried stems. For basil, also pinch off the flowers as soon as they appear if you want to prolong leaf production.
Avoid pruning back an herb plant entirely during a heat spell. Leave enough foliage so it can continue photosynthesis and better withstand the heat.
Which vegetables can be pruned in summer?
Vegetable pruning isn’t always essential. It can, however, encourage ripening or prevent the plant from becoming exhausted unnecessarily.
- An Artichokes: cut at the base the flower stalks that no longer bear buds. Leave the still-green foliage in place.
- Eggplants: in regions with short summers, light pruning can help formed fruits ripen. Primarily remove shoots beneath the first branching and diseased leaves. This intervention is optional in hot regions.
After every cut, watch the plant for a few days. Excessive pruning can trigger a water-demanding vegetative restart, especially when the soil is dry.
Climbing plants to manage during summer
Some climbing plants grow quickly and can reach gutters, windows, or the roof. A light intervention helps keep their growth in check.
- Virgin’s bower (Virginia creeper) can be shortened several times during the summer if it becomes invasive. Clear openings and monitor the tiles, but don’t harshly cut back the entire plant.
- Wisteria is usually pruned in July or August. Shorten the long shoots of the current year, leaving five or six leaves on each such shoot.
- English ivy does not always require summer pruning. Remove dead stems and those that threaten windows or the roof. Remember that a dense ivy also serves as shelter for many animals.
Before working on a lush climbing plant, carefully check that no nest is active. If you notice birds coming and going, postpone pruning.
Can hedges be pruned in summer?
Even though privets, boxwoods, or some conifers produce a lot of shoots in summer, it’s better to postpone hedge pruning to September. Hedges serve as shelter and breeding grounds for many birds.
The Audubon Society recommends not pruning hedges or trimming trees from March 16 to August 31. Local rules may be stricter in some areas. In all cases, removing eggs or nests of protected species is illegal.
Summer pruning should therefore only occur when necessary, such as to remove a dangerous branch or to clear a passage. Before any cut, carefully inspect the inside of the hedge.
Once the sensitive period is over:
- privets can be lightly shaped at the end of summer or early autumn;
- boxwoods can be shaped again using clean, disinfected tools to limit disease spread;
- conifers should be pruned moderately, as many do not produce new growth when cut into old wood.
How to prune your plants well in summer?
In the summer, pruning should stay moderate. A large cut reduces the foliage that protects branches and soil from sun. It can also stimulate new growth that is thirsty for water.
Avoid hot, droughty days
Do not prune during extreme heat, during a severe drought, or just before a heat wave. Wait for a cooler period and choose a dry day.
If the plant is water-stressed, start by giving it a deep soak and allow time to recover. Pruning is not a cure for drought.
Prioritize removing unnecessary parts
Summer pruning mostly involves removing:
- spent flowers, unless you want to keep their seeds for biodiversity;
- dead, broken, or diseased stems;
- shoots that crowd a passage or threaten a structure;
- branches that cross and injure each other.
Don’t remove more vegetation than necessary. For shrubs, a major renovation pruning is usually better tolerated during the period appropriate to each species.
Use clean, well-sharpened tools
A dull pruner crushes stems and leaves ragged wounds. Sharpen the blades and clean them before you begin. Disinfect them after cutting a diseased part and before moving to another plant.
Make a clean cut just above a bud or a well-oriented branch. After pruning, monitor the watering and protect the soil with mulch, being careful not to press it against the stems.
