Scotch Broom (Cytisus scoparius) is a bright and lively-looking shrub, often adorned with bright yellow flowers that lend it an aesthetically pleasing look. Introduced as an ornamental plant in the 1800s and later utilized for erosion control, Scotch Broom has since assumed the role of an invasive and highly destructive species, particularly in North Americas Pacific Northwest and Victoria, BC.
Scotch broom (Cytisus scoparius) is a pretty shrub known for its bright yellow spring flowers. However, it can quickly become unruly and take over your garden if not properly maintained. Pruning is key to keeping scotch broom in check and under control. In this comprehensive guide, we will walk through when, how, and why to prune this invasive plant.
Why Prune Scotch Broom?
There are a few key reasons you may want to prune your scotch broom
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To maintain size and shape. Scotch broom can grow quite large if left unpruned, up to 10 feet tall! Pruning helps keep it a reasonable size for your garden.
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To promote healthy growth. Trimming back old wood encourages new, vigorous growth.
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To remove dead or damaged branches Pruning out disease and pests stops them from spreading
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To control spread. Scotch broom spreads aggressively. Pruning helps prevent it from taking over.
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To improve flower display. Pruning at the right time maximizes flowers.
When to Prune Scotch Broom
Timing is critical when pruning scotch broom. For maintaining size and shape, prune in late spring right after flowering. This is when the plant sets buds for the next year’s blooms. Pruning at the wrong time, like in fall or winter, will dramatically reduce flowers.
You can remove dead or damaged branches at any time of year. But for overall pruning, late spring is best.
How to Prune Scotch Broom
Follow these simple steps for pruning scotch broom:
1. Remove Dead Wood
Cut out any dead or diseased branches back to healthy wood. Sterilize your pruning tools first to avoid spreading disease.
2. Cut Back Old Growth
Prune back any old wood until you see fresh, new green leaves emerging. This stimulates new growth.
3. Thin Out Branches
Selectively remove crossing, damaged, or awkward branches. Use hand pruners for smaller stems and loppers for thicker wood.
4. Reduce Height
If your shrub is too tall, you can cut it back by 1/3 its height. But never remove more than 25% in one year.
5. Clean Up Debris
Safely dispose of all clippings so they don’t re-sprout.
Pruning Tips
Follow these best practices when pruning scotch broom:
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Wear gloves to protect your hands from scratches.
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Use clean, sterilized, sharp pruning tools to make clean cuts.
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Cut at a 45 degree angle just above a leaf node.
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Don’t leave stubs – these invite pests and diseases.
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Never remove more than 25% of growth in one year.
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Take your time and don’t rush the job.
When to Start Pruning Scotch Broom
For best results, begin pruning scotch broom while plants are still young. This encourages bushy, compact growth rather than long, leggy stems. Prune lightly each year, rather than severely pruning overgrown plants.
Alternative to Pruning: Removing Scotch Broom
Since scotch broom is highly invasive in many areas, some gardeners opt to remove it altogether. Cutting alone is not effective since its seeds sprout easily. Combining pruning with digging up roots can help fully eradicate scotch broom over time. Always check first if scotch broom is banned in your region.
With its bright yellow blooms, scotch broom adds vibrant color in spring. But its aggressive growth habit means it requires vigilant pruning and maintenance. Follow these tips to prune scotch broom correctly and keep this invasive shrub under control in your garden. Consistent pruning encourages healthy, compact growth, improves flower display, and prevents unwanted spread.
Pull broom out from the roots
Small and young broom plants can be pulled out from the roots. This is easiest when the soil is soft and wet.
Do it at the right time of year
Broom is most likely to die if cut while it is flowering (bright yellow flowers). Broom flowers during spring and summer.
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FAQ
When should you cut back Scotch broom?
Prune or shear back immediately after flowering to control size, and remove stray shoots or damaged limbs anytime. Remove 1/4 of old stems from the base each year. Feed at least twice during the growing season with a slow release fertilizer in early spring and again mid-summer.
How do you prune an overgrown broom?
How to prune broom. Cytisus should be pruned after flowering to ensure a good display of flowers the following year. Cut off the parts of the stems that have flowered, taking care not to cut into old wood.
How to cut Scotch broom?
Cutting is most effective after a period of dry weather in the summer (July to September). Plants should be cut as close to the ground as possible. The cut plants should be monitored for new growth and cut again, as needed. Scotch broom can be controlled using specific herbicides.
What is the best way to control Scotch broom?
Glyphosate (e.g. Aquamaster, Roundup): can effectively control Scotch broom. Apply to actively growing plants in spring.
When should a Scotch broom be pruned?
The first rule for pruning a scotch broom shrub involves timing. Although broken or diseased branches can be pruned off at any time of the year, size or shape pruning should only be undertaken in late spring, immediately after flowering. This rule about pruning a scotch broom shrub in springtime is critical if you want an attractive bush.
How do you prune a Scotch broom?
Here’s how it works. Scotch broom (Cystisus scoparius) is an attractive shrub that rises to about 10 feet (3 m.) high with an open, airy growth pattern. Despite the beauty of its bright yellow spring flowers, it can easily look disheveled if not pruned correctly. Pruning a scotch broom shrub must be done conservatively and at the correct season.
Can you cut a Scotch broom back?
If you cut these branches back severely, you are not likely to get a fuller plant; in fact, if you prune a scotch broom shrub in this manner, you may kill it. Note: Although broom plants produce attractive, sweet-pea like blooms, they have become highly invasive in many areas. Do Scotch Brooms Bloom on old wood?
Do Scotch brooms look disheveled?
Scotch broom (Cystisus scoparius) is an attractive shrub that rises to about 10 feet (3 m.) high with an open, airy growth pattern. Despite the beauty of its bright yellow spring flowers, it can easily look disheveled if not pruned correctly. Pruning a scotch broom shrub must be done conservatively and at the correct season.
Why is my scotch broom not blooming?
Leggy growth with bare lower branches. Dead wood accumulating inside and bottom of shrub. Shrub exceeds its allocated space. Flower production has declined. Pruning scotch broom regularly in spring after flowering removes old wood, shapes growth, and encourages bountiful blooms.
Do Scotch Brooms Bloom on old wood?
Because most varieties of Scotch Broom bloom on old wood, any pruning should be done just after flowering, whether to remove scraggly or damaged stems or for shaping and aesthetic purposes. Do this at the right time of the year to ensure masses of blooms the following season.