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To prune erysimum, you simply need to snip off spent flower spikes and lightly shape the plant after its main blooming flush to encourage a second round of flowers.
Learning how to prune erysimum is one of the most rewarding tasks in the garden because these vibrant perennials respond so beautifully to a quick trim.
Whether you’re growing the classic Bowles’s Mauve or a fiery orange variety, pruning erysimum regularly keeps the plant compact, bushy, and covered in blooms for months on end.
In this post, we’ll cover exactly when to prune erysimum, the best technique for cutting back erysimum, and how a simple deadheading routine can transform your border.
Let’s dive into the simple art of pruning erysimum so you can keep your wallflowers looking their very best.
How to Prune Erysimum: The Core Method
Pruning erysimum is all about timing and using the right snip.
The golden rule for pruning erysimum is to avoid cutting into old, woody growth because these plants don’t regenerate from bare stems.
Instead, you’ll focus your pruning erysimum efforts on the soft, green growth and the fading flower spikes.
Let’s break down the step-by-step method for pruning erysimum that works for every variety.
1. Deadhead Spent Blooms Regularly
The simplest way to prune erysimum is to deadhead as soon as flowers start to fade.
When you deadhead erysimum, you’re removing the entire flower spike down to where it meets the main stem or a healthy leaf joint.
This prevents the plant from putting energy into seed production and instead forces it to push out new flower buds.
Regularly pruning erysimum this way during the growing season can keep it blooming from spring well into early autumn.
Just use clean, sharp secateurs and make a clean cut at a slight angle.
2. Give It a Hard Trim After the First Flush
After the main spring bloom has finished, you should prune erysimum more aggressively.
At this point, take your shears and cut the entire plant back by about one-third to one-half of its height.
This hard pruning erysimum works wonders because it encourages a fresh flush of new basal growth and a second, reliable round of flowers later in the season.
When you prune erysimum this hard, be sure to cut just above a leaf node or a small side shoot.
This keeps the plant looking neat and prevents it from becoming leggy and sprawling.
3. Shape and Tidy the Plant’s Form
Beyond just removing spent flowers, you can prune erysimum to shape it into a tidy, rounded mound.
As you’re pruning erysimum, look for any stems that are sticking out awkwardly or growing too tall.
Trim these back to match the overall shape of the plant.
Even a simple light trim of the tips of the green growth will encourage bushiness and make pruning erysimum feel like an instant makeover.
When to Prune Erysimum for the Best Results
Knowing when to prune erysimum is just as important as knowing how.
Doing it at the wrong time can mean sacrificing a season of flowers.
Here’s the timing you need for pruning erysimum in different seasons.
1. Prune Erysimum in Early Spring
If the winter has left your erysimum looking ragged, you can lightly prune erysimum in early spring.
At this point, you’re just tidying up any frost-damaged or broken stems and trimming back the tips to encourage branching.
Just avoid heavy pruning erysimum at this stage because the plant is about to set its flower buds.
A gentle finger-and-thumb pinch of the growing tips is the perfect spring pruning erysimum move.
2. Prune Erysimum in Mid-Summer
The most important time to prune erysimum is right after the first big flowering wave in early summer.
This is your window for the hard cut-back that will define the rest of the season.
When you prune erysimum in mid-summer, you’re essentially resetting the plant for a glorious autumn display.
Don’t be shy with the shears at this point; the plant is vigorous and will bounce back quickly.
3. Avoid Late Autumn Pruning Erysimum
You should generally avoid hard pruning erysimum in late autumn.
Cutting back erysimum this late will encourage tender new growth that won’t have time to harden off before the first frost arrives.
That fresh, soft growth will likely get killed off and can weaken the whole plant.
Instead, leave your pruning erysimum for early spring unless it’s a very mild climate.
Common Mistakes When Pruning Erysimum
Even the most experienced gardeners can slip up when they prune erysimum.
Let’s look at the common pitfalls so you can avoid them.
1. Cutting into the Woody Base
The biggest mistake you can make when pruning erysimum is cutting down into the woody, old stems.
Unlike some shrubs, erysimum does not sprout new growth from old wood.
If you prune erysimum back to the bare, brown woody stems, you might kill the plant entirely.
Always keep your cuts in the green, leafy part of the stems.
2. Pruning Erysimum Too Early in Spring
While a light tidy is fine, pruning erysimum too hard in early spring can remove the emerging flower buds.
You might end up with a lovely bushy plant that produces no flowers at all.
So, always wait until the first flowers have started to fade before you do any serious pruning erysimum.
3. Using Blunt or Dirty Tools
When you prune erysimum, you want a clean cut.
Blunt secateurs can crush the stems, making them vulnerable to fungal diseases.
Wipe your blades down with a bit of disinfectant before you begin pruning erysimum to avoid transferring any diseases from other plants.
So, How to Prune Erysimum the Right Way?
Pruning erysimum is all about deadheading spent flowers and a timely hard trim after the first flush.
By learning how to prune erysimum with these simple steps, you avoid the woody center and promote endless fresh growth.
Remember, when you prune erysimum, use sharp shears, keep your cuts clean, and always cut above a leaf joint in the soft green growth.
This easy maintenance keeps your wallflowers compact, healthy, and smothered in gorgeous, fragrant flowers for the longest possible season.
So, get out your secateurs and give your erysimum the confident prune it deserves.