Your Cool Home is supported by its readers. Please assume all links are affiliate links. If you purchase something from one of our links, we make a small commission from Amazon. Thank you!
When to prune lemongrass is a question that comes up for every gardener who grows this fragrant, fast-growing beauty.
The simple answer is that you should prune lemongrass at several key times throughout the year to keep it healthy, productive, and looking its best.
You’ll want to prune lemongrass in early spring for a fresh start, throughout the growing season for maintenance, and again in late fall to prepare for winter.
Knowing when to prune lemongrass isn’t just about grabbing a pair of shears whenever you feel like it, it’s about timing that matches the plant’s natural growth cycle.
In this post, we’ll dive deep into all the moments when pruning lemongrass is beneficial, plus the simple techniques to do it right every time.
Let’s dig into the perfect schedule for keeping your lemongrass thriving.
When to Prune Lemongrass: The Essential Timing Guide
The best time to prune lemongrass depends on your climate and the season, but there are a few universal rules that apply almost everywhere.
For most gardeners, pruning lemongrass in early spring is the most critical cut you’ll make all year.
This is when you remove all the dead, brown, and frost-damaged foliage from the previous winter to make room for vibrant new green shoots.
If you live in a warm, frost-free region, you can also prune lemongrass lightly throughout the summer to encourage bushier growth and more tender stalks.
And in the fall, pruning lemongrass helps you manage the plant’s size before it goes dormant or before you move it indoors for the colder months.
1. Early Spring: The Major Annual Prune
Early spring is the number one answer to the question of when to prune lemongrass.
Once the danger of frost has passed and you start seeing new green growth poking up from the base, that’s your signal.
At this point, you should cut the entire plant back hard, removing all of last year’s tall, woody, and dried-out stalks.
You can safely cut lemongrass down to just a few inches above the ground because it regrows vigorously from the root system.
This hard prune gives the plant a clean slate and channels all its energy into producing fresh, tender stalks that are perfect for cooking.
Skipping this spring prune is the most common mistake, and it leads to a messy clump full of dead material that chokes out new growth.
2. Mid-Summer: Light Maintenance Pruning
Another great time to prune lemongrass is in the middle of summer when the plant is in full swing.
This isn’t a hard cut like spring; it’s more about tidying up and encouraging a fuller, denser clump.
You can prune lemongrass in summer by snipping off any stalks that are flopping over, looking yellow, or have gone to seed.
Removing spent flower stalks is especially important because they signal the plant to slow down leaf production.
By pruning lemongrass this way, you keep the energy focused on the stalk growth you actually want to harvest.
It’s also a great opportunity to harvest some of those outer stalks for your kitchen, so you’re pruning and reaping at the same time.
3. Late Fall: Pre-Winter Preparation
When to prune lemongrass in the fall is all about preparation for the dormant season.
If you live where winters are cold and freezing is a real threat, fall pruning is your friend.
About four to six weeks before your first expected frost, you should prune lemongrass back by about two-thirds of its height.
This reduction helps the plant focus on strengthening its roots rather than supporting a massive top of leaves that will just die back anyway.
For gardeners in warm climates, this fall prune is more about controlling size and preventing the clump from becoming too unruly.
Either way, pruning lemongrass in the fall keeps the plant manageable and reduces the risk of wind damage or rot from wet, heavy foliage.
How to Tell When Pruning Lemongrass Is Urgent
Beyond the seasonal schedule, there are certain visual cues that tell you it’s time to prune lemongrass regardless of the calendar.
You don’t always have to wait for a specific month, sometimes the plant just tells you it needs a haircut.
1. Dead or Browning Leaves Are Taking Over
If more than a third of your lemongrass clump looks brown, crispy, or dried out, it’s time to act.
This can happen after a heatwave, a drought, or even just at the end of the growing season.
Prune lemongrass by removing all the dead blades right down to the base to keep the center of the clump healthy.
Leaving decaying leaves in place invites pests and fungal diseases that can kill the whole plant.
2. The Clump Has Outgrown Its Space
Another urgent time to prune lemongrass is when it’s invading space meant for other plants or blocking a walkway.
This grass can get huge, reaching four to six feet tall and wide if left unchecked.
When the clump starts to sprawl, do a hard prune and trim it back to a more compact shape.
You can also divide the clump at this time, which is basically pruning lemongrass at the root level, to create new plants.
3. After a Freeze or Frost Event
If an unexpected frost hits your lemongrass, don’t panic, just prune it once the weather warms up again.
You’ll prune lemongrass by cutting away all the mushy, blackened, or water-soaked foliage that the frost killed.
This prevents the dead tissue from rotting and allows any surviving healthy shoots to emerge.
Often, even if the top is totally killed, the roots survive, and a proper prune in spring will bring it back to life.
Signs That You Should NOT Prune Lemongrass
Knowing when to prune lemongrass also means knowing when to leave it alone.
There are a couple of scenarios where pruning is actually harmful to the plant.
1. During Extreme Heat or Drought
Avoid pruning lemongrass during the hottest part of a summer heatwave.
A hard prune removes the leaves that are providing shade and moisture retention for the root system.
This can stress the plant severely and cause it to go into shock when it’s already struggling.
If it’s sweltering, wait until temperatures drop a bit before you do any major pruning.
2. Right Before a Predicted Hard Freeze
You shouldn’t prune lemongrass right before a hard freeze, even if it looks shaggy.
The dead foliage actually acts like a protective blanket for the crown of the plant.
Cutting it down just before a freeze exposes the tender inner core to ice damage.
It’s better to wait until the freeze has passed and then prune lemongrass in the early spring cleanup.
So, When Should You Prune Lemongrass?
You should prune lemongrass primarily in early spring with a hard cutback, lightly in summer for maintenance, and again in fall for winter prep.
This schedule keeps the plant vigorous, productive, and free from dead matter that invites disease.
You should also prune lemongrass whenever you notice excessive browning, overcrowding, or damage from a frost event.
Just remember to avoid pruning during extreme heat or right before a deep freeze, since those times leave the plant vulnerable.
With this timing guide in mind, you can prune lemongrass confidently and enjoy a lush, aromatic clump that gives you fresh stalks all season long.
Happy gardening, and don’t be shy with those shears, your lemongrass will thank you for it.