How to trim a locust tree

Black locust tree or false acacia

Black locust tree, which is also called false acacia, is a tree species considered invasive.

Black Locust facts, a summary

NameRobinia pseudoacacia
Type – tree

Height – 30 to 50 feet (10 to 15 meters)
Exposure – full sun
Soil – ordinary

Foliage – deciduous
Flowering – June
Fruit formation – summer

  • Read also: other Acacia tree care and varieties

Planting black locust tree

Plant preferably in fall to favor root development before winter and proper regrowth in spring.

If purchased in a container, you can also plant it in spring, taking great care to increase watering at the beginning.

  • Black locust tree loves full sun, that’s where it blooms best.
  • A mix of garden soil and planting soil mix is perfectly suited to grow it.

Pruning and caring for black locust tree, false acacia

No specific pruning is required, but it is important to remove dead or weak branches whenever you notice them.

  • Eliminating dead and diseased branches must be performed regularly.
  • In fall, prune branches that cross over each other and in-growing branches.
  • Snip off suckers in fall, they are quite useless to the tree.

It is also possible to restrict this tree’s growth by pruning it or removing larger branches in fall.

Black locust wood is naturally rot-resistant

Black locust wood naturally resists rot and insects. It is excellent to make fence posts and other garden items from.

A raised garden bed made from black locust will last decades. Use slabs of black locust to make edges in your raised garden. Unlike regular logs, these won’t need to be replaced every three or four years.

Many stores sell swing sets made from chemically treated wood or metal, but black locust is a perfect alternative.

It’s also possible to build a terrace with black locust. Simply check with the supplier that the wood comes from heartwood, not sapwood.

  • Heartwood is the portion of the trunk that is already older than three or four years.

Drawbacks of black locust wood for building

Black locust has a tendency to warp and twist upon drying.

  • It’s important to layer it well, with slats to keep each board in position.
  • Once drying is complete, it won’t budge.

Also, black locust is slightly more brittle than other woods.

  • Cushion gates with a slab of softer wood or a rubber stop. This will avoid slamming that might crack the wood.
  • When building the terrace, drill holes for screws and nails, especially near board ends.

Learn more about black locust tree

Black locust tree got its scientific name Robinia from its inventor or discoverer Jean Robin, the royal botanist of Henry the IVth of France who planted it for the 1st time Place Dauphine, in Paris, in 1601.

Native to the United States of America, false acacia, which also goes by the common name black locust tree, is a very elegant tree with a balanced bearing. Its hardiness leads it to live a very long life.

  • This fast-growing tree is particularly interesting for the color of its flowers.
  • A great nectar producer, the flowers from this tree will enthrall bees who will come to pollinate it.

Fruits form pods and come from flowers that cluster in very fragrant bunches of white or red when they appear in June.

The green leaves may fall off in fall without even having turned brown. They shimmer and sway and make this tree look alive.

Smaller black locust for small gardens

An interesting variety stays smaller as it grows. It’s called Robinia pseudoacacia ‘Umbraculifera’, because the canopy looks similar to an umbrella!

  • This variety doesn’t grow as tall and tops out at around 20 feet or 6 meters.

Smart tip about false acacia

Upon planting, spread some mulch at the base of the tree and you’ll avoid weed growth!

Image credits (edits Gaspard Lorthiois):
Pixabay: Valter Cirillo
CC BY 2.0: Melissa McMasters
own work: Rosalyn & Gaspard Lorthiois

Pruning trees and shrubs | UMN Extension

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Quick facts

  • Pruning changes the form and growth of a plant.
  • Pruning can also be considered preventive maintenance for both insect and disease damage.
  • Many problems may be prevented by pruning correctly during the formative years for a tree or shrub.
  • The late dormant season is the best time for most pruning.

Prune to promote plant health

  • Remove dead or dying branches injured by disease, severe insect infestation, animals, storms, or other adverse mechanical damage.
  • Remove branches that rub together.
  • Remove branch stubs

Avoid topping trees. Removing large branches leaves stubs that can cause several health problems. It also destroys the plant's natural shape and promotes suckering and the development of weak branch structures.

Prune to maintain intended purposes for plants in a landscape

  • To encourage flower and fruit development.
  • To maintain a dense hedge.
  • To maintain or encourage a desired plant form or special garden forms.

Prune to improve plant appearance

Appearance in the landscape is essential to a plant's usefulness. For most landscapes, a plant's natural form is best.

Avoid shearing shrubs into tight geometrical forms unless they need to be confined or trained for a specific purpose. When plants are properly pruned, it's hard to tell that they've been pruned.


  • Controls plant size and shape.
  • Keeps shrubby evergreens well-proportioned and dense.
  • Removes unwanted branches, waterspouts, suckers and undesirable fruiting structures that detract from plant appearance.

Prune to protect people and property

  • Remove dead branches.
  • Have hazardous trees taken down.
  • Prune out weak or narrow-angled tree branches that overhang homes, parking areas, sidewalks and anyplace falling limbs could injure people or damage property.
  • Eliminate branches that interfere with street lights, traffic signals and overhead wires.  
    • DO NOT attempt to prune near electrical and utility wires. Contact utility companies or city maintenance workers to handle it.
  • Prune branches that block vision at intersections.
  • For security purposes, prune shrubs or tree branches that obscure the entry to your home.

How to prune trees and shrubs


When to prune

The late dormant season (late winter to early spring) is best for most pruning.


  • Apricot
  • Azalea
  • Chokeberry
  • Chokecherry
  • Clove currant
  • Flowering plum
  • Flowering cherry
  • Forsythia
  • Juneberry
  • Lilac
  • Magnolia
  • Early blooming spirea
  • Alpine currant
  • Barberry
  • Buffaloberry
  • Burning bush
  • Dogwood
  • Honeysuckle
  • Ninebark
  • Peashrub
  • Purpleleaf sandcherry
  • Smokebush
  • Sumac

Reviewed in 2022

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Why cut acacias?

“They cut all the acacias along the street along our house, but right under the stump! This beauty has been destroyed! That's why they do it, one might say? You journalists, why don't you write about it?!” - a resident of Ust-Ilimsk is indignant . ..

Sawn bushes on the street. Dreamers

Many acquaintances told me about sawing off the green part of the acacias in some parts of the city. For me, the most unsightly picture of bare lawns causes bewilderment and regret. Walk around the city! And you will see completely bare stumps in place of lush, rich bushes. Bald and sad - this is how you can describe the picture that opens up to your eyes. Acacia alleys along Heroiv Truda (1st and 2nd microdistricts), along Dreamers (4th microdistrict) fell under the knife ...

Who did this? What for? Shrubs were cut down not in the local area, but in the municipal area. It is logical to assume that this was done under a municipal contract by contractors who maintain green areas, footpaths in green areas and sidewalks along the perimeters of microdistricts. But, as it turned out, this year it was the pruning and formation of crowns of shrubs on lawns along city roads (between the part and sidewalks) are carried out by other contractors: Avtodor LLC on the right bank, and IP Tarasova on the left bank. As explained on the city website, these works are included in municipal contracts for the maintenance of public roads. It also says that “the overgrown branches of plants close the view on city highways and interfere with the free movement of citizens along footpaths and sidewalks, besides, they worsen the appearance of city streets. Therefore, in order to put green spaces in order, it is necessary to trim them: all randomly protruding branches are removed from shrubs, and the crowns are given the same height and width.

Well, we can say that the task was completed and exceeded. Not only "chaotic protruding branches" have been removed - all branches have been removed from the bushes! And the crowns are indeed given the same height. Only the crowns, in fact, are no longer there, there are only bare stems of acacias sticking out of the ground. Why were they so robbed? And will such a total pruning harm the shrubs?

As the regulatory documents say (for example, the still current Order of the Gosstroy of the Russian Federation dated 15-12-99 153 “On approval of the rules for the creation, protection and maintenance of green spaces in the cities of the Russian Federation . ..” and other documents), when caring for urban plantings, in particular shrubs, the following types of pruning are used: sanitary, molding, rejuvenating. During sanitary pruning of the crown, old, diseased, drying and damaged branches are removed from the shrub. It is recommended to carry out it annually, during the entire growing season. However, it is not recommended to remove a large number of large branches at the same time! Forming pruning is done to even out the height of plants, to give the crown shape. It should be carried out in early spring, before bud break, or in autumn - after leaf fall. When forming pruning, up to a third of the length of the growth of the previous year is cut off. The deepest pruning is rejuvenating, it stimulates the formation of young shoots that create a new crown. It is made for trees and shrubs, which lose their decorative qualities with age, cease to give annual growth, and form dry peaks. With such pruning, the branches are shortened by 50% -70% of the length, but this must be done in two steps: some of the branches are cut in the first year, the rest in the second. Anti-aging pruning is done in early spring, before the start of sap flow.

As you can see, what was done with acacias in Ust-Ilimsk does not fit into any of the listed types of pruning - neither in terms of the nature, nor in terms of the timing of the work. This was confirmed (on condition of anonymity) by an employee of one of the Ust-Ilimsk enterprises, who, by occupation, takes care of shrubs and has knowledge and experience in this area.

This is one hundred percent non-sanitary pruning, in which dead branches are removed. All branches have been removed here! If we talk about rejuvenation, then in this case the acacia is cut off and on a height of 10-15 centimeters from the ground, but only in a certain period: either in early spring or autumn. You see, there is such a thing - sap flow, this is when juice flows through the plant, when it is already all green. At this time, such an extreme "haircut" is not carried out for most plants, acacias - that's for sure. Usually acacia is cut to a height of two-thirds, i.e. if the plant is a meter high, then the maximum that can be removed is 30 cm, and then - from the newly grown branches. The acacias we are talking about are cut off, according to my estimates, up to 60-70% of the length, - explained Irina K.

She drew attention to the fact that cuts on the left stumps are not protected (according to the rules, cuts with a diameter of more than 2 cm are covered with special compounds immediately after cutting). BUT also, that pruning was done mostly in the heat, that after such a deep pruning, fertilizing and watering must be carried out. None of this has been done. All this can not but affect the plant.

The plant is under stress, it will be more difficult for it to get back into shape. Of course, acacia is a plant that recovers, and most bushes will recover someday. But the fact that the pruning was carried out by unskilled personnel, and the plants were subjected to a certain ny harm - this is unequivocal, - said Irina K.

I decided to ask the contractor what kind of pruning they do? Olga Artyushenko, director of Avtodor LLC, said that the terms of reference that her company received from the DZhP technical department indicated a height of 80 cm. She complained that it was actually impossible to cut bushes higher, they were too tall and lignified, and that it was very laborious Job. It’s hard to argue here, we haven’t cut acacia for a long time, and besides, Avtodor, like other contractors, probably doesn’t have either a special tool for trimming and shaping shrubs, or personnel trained in this particular business.

PTO engineer Olesya Chernysheva reported that the wording in the terms of reference was as follows: “pruning and rejuvenation of shrubs” (in fact, acacias have not been cut in the city for a long time!), And the height to which acacias were cut was not indicated ... When asked, where did the number 80 cm come from and why exactly 80 cm of bare branches should be left, Olesya Leonidovna explained that when the contractors had a question about how high they should cut the bushes, it was decided to bring all the acacias to one type.

“We already have trimmed shrubs, for example, on the median strip…” - said Olesya Leonidovna. This argument, frankly, confused me. Landings on the median and shrubs on the lawn separating the roadway from residential development are, to put it mildly, incomparable things. The main purpose of the dividing strip is the constructive allocation of an impassable section of the road, the impossibility of using it for movement by either pedestrians or vehicles. Thus, road safety is ensured. The task of green spaces on lawns separating residential development from the highway inside the settlement is different.

“Green spaces on the streets and roads must protect the population from noise, dust, exhaust gases from automobiles and meet architectural and artistic requirements. ... For better isolation of buildings from traffic ... transport, trees and shrubs with a dense crown are used, ”clause 5.1 reads. SNiP II-K.3-62.

So what kind of pruning is used in Ust-Ilimsk? Obviously, there will be no answer, because, as it seems to me, there is none. They cut it because it needs to be cut, and it doesn't matter how it will be. And not by malicious intent did our green lawns become bald, but because there are no specialists in the city to care for urban plantings - neither in the municipality, nor in contractor companies. And this is our common problem. Having conceived the total pruning of shrubs on the lawn, no one, most likely, thought that acacias are not only a lawn decoration (although from an aesthetic point of view, I think the city was also damaged). The acacia hedge reduced the noise level from the roads and also partially absorbed the dust from the roads. Of course, in a year or two the plants will recover, come to their senses and give new shoots. By the way, it will also need to be formed into a beautiful crown. Let's hope that by this time we will have an appropriate specialist in the city. We can only wait.

Victoria Galiulina, Vestnik UI LPK

Sergey (27 Jul 2018 at 16:50)

And then they will take on little people. ..

Kirill (July 27, 2018 at 03:53 pm)

They sawed all the trees, now they took up the bushes, and then what? Will you uproot all the grass? All the greenery in the city was destroyed... This summer is somehow anomalous and somehow affects the mayor's office in a special way (or whoever is involved in this felling)

Pruning trees and shrubs

Woody Plants - Shrubs, trees, vines need pruning to look good, bloom profusely, and not overgrow. Pruning has some of the most mysterious rumors that scare away even experienced gardeners, but don't worry, pruning is a very simple technique if you follow a few basic rules.

Trimming tools

Prefer sharp and clean tools. When buying them, give priority to quality. Remember: pruning tool should cut, not crush wood .

The main tool is pruner . When buying, make sure that it fits your hand. Secateurs come in different types: cutting with curved or curved blades, chopping with a straight blade.

Secateurs cut shoots with a diameter of 10-12 cm and dry branches up to 8 cm in diameter.

And if you want to cut large stems or branches, use the pruning saw. Rough cuts are cleaned with a garden knife. Professional gardeners also use a knife to shorten small branches. When pruning thorny bushes, you will need strong gloves. Depending on the size of the hedge, use the manual or electric hedge trimmer .

Why trim?

Any pruning causes the flow of nutrients to the place of cut and causes changes in the growth process of the plant . On the one hand, due to the formation of an influx of tissue, the wound heals quickly, on the other hand, a reorientation of the flow of nutrients occurs, as a result of which the dormant buds located near the wound intensively germinate.

Moreover, the germination of dormant buds will be the stronger, the more radical the pruning was.

This means that with a strong (so-called anti-aging) pruning, you can really rejuvenate the plant.

Pruning in the right place

Inept pruning harms the plant and does not lead to the desired result. In no case should you cut the shoot anywhere. The correct cut point is approximately 3 mm above the kidney. (Figure 1)

In this case, we remove only part of the stem, while cutting at an angle so that the cut surface loses water (for plants that have paired buds, you need to make a straight cut so as not to damage any of them). If you cut too far from the bud, the rest of the stem will dry out, forming an ugly knot and opening the way to disease.

If you are removing entire stems from the plant, cut them together and attach them to the main stem.

If the branch is cut too close to the bud (fig. 2), there is a risk of damaging it. Keep in mind that the position of the bud down to the cut will determine the direction of the new shoot. Therefore, you should always cut towards the outward looking bud so as not to overcrowd the center of the plant with many shoots.

Cutting techniques

1. Shortening

Only the ends of branches are trimmed. Shortening can be to reduce the length or completely remove the shoots. Ultimately, the crown decreases, but stimulates the growth of buds located below the cut, so the plant turns out to be well leafy, branched than before pruning.

2. Thinning

Whole branches are removed up to the trunk, you can cut a couple of branches, or you can remove all the lower ones to form a standard plant. As a result, the remaining branches receive additional nutrition, and the plant grows taller and more spreading than before pruning.

3. Haircut

To maintain the desired shape remove all unnecessary (even healthy) branches.

4. Pinching

Needed for more bushiness and longer flowering . At the same time, plants pinch off or cut off the apical points of growth with a small part of the non-lignified stem. Pinching can be done several times per season.

5. Sawing

Complete removal of large branches . In this case, the branch is cut down obliquely.

6. Summer pruning

At lilacs wilted inflorescences are cut, at rhododendrons the flowers are carefully broken out, trying not to damage the buds. Variegated trees and shrubs sometimes have green shoots, usually much stronger than variegated shoots, and should be cut out immediately.

Types of pruning

When you start pruning, you need to choose the right time for it.

Heavy pruning at the wrong time often leads to a complete lack of flowering, and sometimes to the death of the plant.


    1. Ornamental, deciduous trees and shrubs are pruned at the end of winter - the beginning of spring.
    2. Deciduous trees and shrubs that bloom until the end of May should be pruned after flowering ends, preferably without delay.
    3. Deciduous trees and shrubs that bloom later than the end of May are pruned in early spring - without waiting for the start of growth.
    4. Conifers - in autumn.

There are 3 trim types:

    • sanitary
    • anti-aging
    • shaper

Sanitary pruning

Absolutely all plants undergo sanitary pruning, the main thing is to carry it out correctly. First of all, you need to remove dead shoots. They are immediately visible and easily distinguished from living ones. The low branches of some shrubs dry up in the dense shade of the upper leaves, and the shoot dies. Cut the dried branch "on the ring".

Broken and diseased branches (branches affected by diseases and rotting) are also cut out. On the cut, there should not be a brown color characteristic of the diseased tissue.

Sanitary pruning includes the removal of weak and thickening branches. We cut off too thin and weak shoots, if there are a lot of crossing shoots in the middle of the crown, then cutting out part of the old branches, we leave the crown, making it more powerful and beautiful.

Some shrubs produce strong suckers which should be removed. If the offspring are left, then in a few years dense thickets form.

Sanitary pruning involves trimming branches that are too long and detract from the appearance of the plant.

Pruning often works wonders, and thanks to it, we can prolong and improve the quality of flowering.

Spring-blooming deciduous trees and shrubs (currant, mock orange, jasmine, weigela, deutsia) form their flowers on old shoots. Branches that had flowers, shorten by about 1/3.

Trees and shrubs that bloom in summer (fuchsia, cinquefoil, badley David, combs) form their flowers on young shoots of the current year. Trim old shoots as long as the plant requires. As a result, new, strong, vigorous shoots will appear that will bloom in the same year.

Youth pruning

This pruning is stronger than the sanitary pruning. Anti-aging pruning is done for several reasons:

  • If the plant looks weak, it has long shoots, sparse foliage, twisted branches, and it does not bloom well. But such pruning work must be carried out in 2-3 seasons.
  • Fast-growing trees and shrubs that grow too tall, obscure the site, crowd their neighbors, threaten buildings.

Rejuvenating pruning can be of several types:

1. Raising the crown

After that, the garden becomes brighter and more spacious.

2. Crown removal

This method limits the size of large trees, or stimulates the formation of a cap of beautiful young shoots.

3. Crown reduction

With this haircut, we get the desired size for a bush or tree.

4. Pruning "on a stump"

Absolutely all shoots are cut down to 3-5 cm on the soil. As a result, the bush is completely rejuvenated (pruning "on a stump" is not suitable for all shrubs).

Anti-aging pruning "on the stump" occurs in stages. In the first year, cut the oldest shoots under the base (3-4 pieces). The following year, 3 more pieces, and then every year remove 1-2 shoots until the bush is completely renewed.

Formative pruning

This type of pruning is best seen with vines. By tying shoots to guide sticks or cords immediately after planting, we take the first step in forming its branches. In the first summer, the plant develops rapidly, forming new shoots, and while they are still flexible, they give them the desired direction of growth, and carefully fix them on supports. In the spring, the first pruning is done, the side shoots are cut to a suitable bud, and the unnecessary ones are cut off entirely, too thickened places are thinned out in depth. The following spring, several new shoots are formed from dormant buds at the sites of cuts of lateral shoots, to which we give the desired direction of growth, and which already at this stage allows us to predetermine the basic shape (skeleton) of the plant.

Then this procedure is repeated for the next, that is, the third year.

In addition to the sanitary, rejuvenating and shaping pruning from , there is a genus of shrubs that require special pruning . These are shrubs with colored stems, shrubs with ornamental foliage, and shrubs with gray leaves.

Shrubs with colored leaves is dogwood grown for its stems. For vigorous growth of new, richer stems, prune in early spring. Simply reduce the previous season's shoots to about ground level to form a short brush of stems.

Ornamental foliage shrubs These include Elderberry . It has especially attractive foliage when young, and becomes less attractive as it matures.

Learn more