Each shrub has different requirements for its care. We show when is the best time to cut each bush and give tips on the correct procedure for pruning.
With their appearance, fruit and flowering, shrubs enrich the aesthetics of our garden, our diet and the diet of wildlife and insects. However, for a variety of reasons, it may become necessary to prune a shrub. Perhaps your shrub or bush has grown too large, is no longer blooming well, or contains a lot of dead wood. You may also be asking yourself the questions: Until when is it permissible to prune bushes and trees? And how does professional pruning actually work? We explain the legal situation, tell you the correct pruning techniques and give examples of different shrubs.
What is a shrub?
Shrubs are plants that are perennial, fully woody and grow with multiple shoots. With this definition, shrubs can be quite clearly distinguished from trees, which are also woody, but grow with only one main shoot – the trunk. Typical examples of shrubs are the rose, witch hazel, gooseberry, hazel or privet. Shrubs are planted as purely ornamental or as a hedge for privacy. Often, however, the fruit or flower of the shrub also plays a role, as is the case with currant, blueberry or elderberry. Because many shrubs provide valuable nesting opportunities and food sources for wildlife, they are also often used for ecological enhancement of gardens and landscapes.
The best time to cut shrubs
Many amateur gardeners are uncertain when it comes to the question of when to cut a shrub. And it’s no wonder: it’s not even possible to determine a common best time to cut all shrubs. Shrubs belong to a wide variety of plant families, are evergreen or deciduous, and flower or fruit at different times. If you want to cut all your shrubs in the fall, that may be optimal for some to stimulate growth the following year. Other shrubs, however, will repay a fall pruning with frostbite in the winter or a poor bloom in the spring. To help you find the right pruning date for your shrubs, we have compiled below when it is best to prune shrubs.
|Spring bloomers||Immediately after flowering||Pruning later in the year would remove flower buds|
|Summer bloomers||December till March||Pruning to thin out, stimulate new growth, rejuvenate, often promotes more vigorous flowering|
|Fruit trees||December till March||pruning, rejuvenation pruning, promotion of new fruiting wood.|
|Fruit trees summer pruning||July till September||Promotes fruit quality and fruit coloration, not mandatory|
|Hedge trimming deciduous trees||December – March, June – August||Pruning to stimulate the branching of the hedge, also possible twice a year if necessary.|
|Roses||After flowering, before 15 July||To maintain frost hardiness, for renewed flowering or to stimulate flower bud formation for the following year.|
Most shrubs do not need and should not be cut annually. Such shrubs that need annual pruning are rather exceptions, which you will learn more about in the course of this article. Aside from the proper timing of pruning throughout the year, two general rules apply when it comes to when to cut shrubs:
Don’t cut shrubs if frost or high heat is expected the following week.
Do not prune in full sun. An overcast, slightly cooler day is optimal, preferably with some rain. You should also avoid pruning shrubs during frosty weather, as this can cause damage to the cut wood.
How to cut back shrubs
Even though shrubs have a typical, even shrub-like growth, the correct pruning in each case varies from plant to plant and also depends on the goal of the pruning.
Hedges, topiaries and groundcovers are regularly pruned on the surface to achieve dense branching. Pruning is not done on the inside.
Shrubs whose shoots arise from the base such as hazelnut, forsythia, deutzia, and philadelphus are thinned only close to the ground. Tightly growing shoots are not pruned in height and at the tips, if possible. Only saws, loppers and rose shears are used. Dead wood is also cut out.
Shrubs that branch halfway up the tree, such as the weigelie, dogwood, or rhododendron, are thinned out internally and, rarely, at the base. The tips of the shoots are left untouched. Only saws, loppers and rose shears are used. In addition, dead wood is cut out.
The rule is that the pruning of a shrub should pick up its normal growth – and in such a way that a good pruning is not obviously noticeable at first glance by its unnaturalness.
Tip: Common pruning mistakes with shrubs
A bad pruning completely ignores the growth habit of a shrub. Good examples are the cubes and bobble heads, also known as “janitor pruning”. This involves using hedge clippers to turn any shrub into a topiary. Unfortunately, however, not every type of shrub is suitable as a topiary and acknowledges the pruning with an unattractive, unnatural growth, a greatly reduced set of blossom and fruit and a broom-like sprouting in the following year.
Pruning ornamental shrubs
When pruning ornamental shrubs, you can well follow the above timing and pruning rules. But, of course, there are some special cases, which we would like to present here in detail.
Ornamental shrubs that need annual pruning
Some ornamental shrubs require mandatory annual pruning. As a rule, these are frost-prone shrubs that suffer frostbite in winter anyway. The following shrubs absolutely need such pruning:
- Butterfly bush (Buddleja davidii).
- Bearded flowers (Caryopteris)
- Säckelblume (Ceanothus americanus – hybrids)
- Scarlet fuchsia (Fuchsia magellanica)
- Many species of St. John’s wort (Hypericum)
- Cinquefoil (Potentialla fruticosa)
- Silver bush (Perovskia abrotanoides)
- Roses (Rosa): noble roses, bedding roses, shrub roses, historical roses
In March, check which shoots have frost damage and therefore do not sprout normally. These are then removed at the base or cut down to the point of emergence of a healthy, strong side shoot or undamaged bud.
Pruning evergreen shrubs
Evergreen shrubs are pruned using what is known as concealed pruning. It is so named because the cuts, if done well, are barely visible. They are located inside the shrub and hidden behind leaves. Pruning is always done in such a way that no bare “stumps” are left. A cut is always made above an existing side shoot or the entire branch is removed completely. This allows shrubs to be thinned out inconspicuously and reduced in size.
Evergreen shrubs can be a bit of a bitch as bushes, so below you’ll find important tips on how to properly prune these green beauties.
Yews (Taxus): Very tolerant of pruning and suitable as topiary or hedging. With free growth no pruning necessary. By pruning also education to tree form possible. Best pruning time: March to July. Heavy pruning into old wood is well tolerated in March.
Spruces (Picea): Difficult as hedge or topiary because not very tolerant of pruning. The remedy is annual pruning between August and September or February and March. This involves hand pruning the youngest shoots just above the clearly visible buds. Cutting into the old wood leads to unpredictable and uneven growth.
Heather (Erica, Calluna): pruning immediately after flowering. With hedge clippers cut only a few centimeters from the top. Late-flowering broom heather (calluna) should not be pruned until spring. Pruning encourages flowering the following year. Severe pruning is not tolerated.
Pines (Pinus): difficult as a hedge and topiary because of uneven growth. The remedy is annual pruning in early June: the youngest shoots are cut in half by hand. However, the pine hedge always remains quite irregular – that is part of its charm. No pruning is recommended for free growth. Pruning into the old wood is not tolerated. Best time for pruning: March to June (unless birds are breeding in the hedge!) or in September. No pruning necessary for free growth. Pruning into old wood is poorly tolerated.
Tree of life and false cypress (Thuja, Chamaecyparis, Cupressozyparis): Are usually pruned as hedges or columns, then surface cut with hedge shears. Care must be taken to ensure that the branches left standing still retain green needles or scales. For more information, see the special article on pruning arborvitae.
Rhododendrons (Rhododendron): after flowering, the old fruiting branches are broken out to increase flowering the following year. Rhododendrons tolerate pruning well and can be cut back to the old wood if necessary. If the shape is only to be maintained, only the young, green shoots should be pruned above the clearly visible buds in each case. The best time for pruning is March. Want to know in more detail? Our special article on pruning rhododendrons can certainly help you.
Tip: Is it okay to cut conifers back to the old wood?
The answer here is a clear no. Most conifers, especially spruces (Picea), firs (Abies) and Douglas firs (Pseudotsuga), but also trees of life (Thuja) and cypresses (Chamaecyparis), as well as many other conifers, do not tolerate heavy pruning into the old wood very well. Heavily cut shoots are unable to sprout again, dry up and die. The resulting damage cannot be repaired. An exception is the extremely pruning-tolerant yew (Taxus).
There are two types of pruning for roses: pruning between March and April and summer pruning in July and August. The March/April date is the appropriate time for almost all roses to stimulate growth and bloom for the new year through vigorous, deep pruning. Even if the rose has not suffered much damage from the winter frost, it is still pruned just above the second to third bud – as seen from the ground. Excluded from this practice are wild roses, ground cover roses and climbing roses. And special rules also apply to stem roses. Summer pruning in July/August promotes abundant flowering of roses. Only the faded inflorescences or even whole young shoots can be removed. However, from July 15, cutting the shoots should be omitted, otherwise the winter hardiness of the rose will suffer.
Tip: Pruning climbing roses and park roses
Single-flowering roses – often the historic varieties – and climbing roses should be pruned only when they get out of shape. Some of them bloom on two-year-old wood, which would be completely lost in a radical pruning.
Pruning the queen of roses is a science in itself. Therefore, more detailed information can be found in the special article on “Pruning roses”.
Pruning berry bushes correctly
As with the timing of pruning, berry bushes have different requirements than most shrubs when it comes to proper technique. Prune berry bushes as follows:
Currants (Ribes): after harvest, remove older shoots (4 years and older) near the ground. For black currants, additionally shorten younger shoots, but do not cut them completely. For details, see the special article on pruning currants.
Blackberries (Rubus fruticosus): the older, biennial shoots can be cut down after harvest, but perennial fruiting is also possible. For more detailed information, see the special article on pruning blackberries.
Raspberries (Rubus idaeus): Worn canes are cut off at ground level after harvest. Double-bearing varieties are not cut until March. For many practical tips, see the special article on pruning raspberries.
Gooseberries (Ribes uva-crispa): the older shoots (older than 2 years) can be pruned, leaving the younger ones. Prune the bushes so that there is enough space between the branches for picking – this makes picking easier and prevents injury to the prickles. If you’d like to know even more, feel free to stop by the special article on pruning gooseberries.
Blueberries (Vaccinium corymbosum): older, gray branches and thin twigs are removed annually, leaving a few strong old biennial and annual branches each. If you are looking for practical, detailed instructions, you will find them in our special article on pruning blueberries and blueberries.
Do not cut shrubs at all or cut them rarely
Wild shrubs, whether free-standing or in wild hedges, should be cut rarely or not at all. This is because they provide shelter and food for birds, mammals and insects. Even solitary, i.e. standing alone, woody plants do not need to be cut – this way, the full beauty of their very own, natural form unfolds over the years. In general, most ornamental shrubs show their best side without pruning. The prerequisite for this is, of course, that the individual shrubs have been given sufficient space when planted. Even if the available standing space is somewhat narrow, a need pruning is sufficient for very many shrubs. In other words, pruning is done only when the plant is bothering, getting out of shape, or becoming lazy with flowering.
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