If you’re growing lemongrass, knowing how to prune lemongrass is essential for a healthy, productive plant. This simple step-by-step guide will show you exactly when and how to cut it back for the best results.
Pruning isn’t just about control. It encourages fresh, tender growth, prevents the plant from becoming woody, and gives you plenty of flavorful stalks to use in the kitchen. Whether your plant is in a pot or the ground, the process is straightforward.
How to Prune Lemongrass – Simple Step-by-Step Guide
Let’s get straight to the main process. You only need a few tools, and the whole job takes just a few minutes. Here’s what you’ll need to gather first.
Tools You Will Need
- Sharp Pruning Shears or Scissors: Clean, sharp blades make a clean cut that heals quickly. Dull tools can crush the stalks.
- Gardening Gloves: The edges of lemongrass leaves can be surprisingly sharp and cause minor cuts.
- A Container or Basket: For collecting your harvested stalks and trimmings.
When is the Best Time to Prune?
Timing is key for a successful prune. The best time for a major cutback is in late winter or early spring, just as new growth begins to appear at the base. This gives the plant the entire growing season to recover and flourish.
During the active growing season (spring and summer), you can do light, frequent pruning for harvest. In fall, you should stop pruning to allow the plant to harden off before colder weather. If you live in a frost-free climate, you can prune year-round.
Step-by-Step Pruning Instructions
Follow these steps in order for the healthiest plant. Always start by inspecting your lemongrass clump from all sides.
Step 1: Identify the Stalks to Cut
Look for older, outer stalks. These are typically thicker, woodier, and may be turning brown or yellow. Also target any stalks that are dead, damaged, or flowering. The fresh, green, and tender new growth usually comes from the center of the clump.
Step 2: Make Your Cut at the Right Place
For harvesting or thinning, cut the selected stalk as close to the soil level as possible. Aim for within an inch of the base. Cutting higher up leaves a stump that can die back and look unsightly.
If you just want to trim the leafy tops, you can cut the leaves about halfway down. This is less common but useful if the plant is getting too tall and leggy in a pot.
Step 3: Thin Out the Clump
Don’t be afraid to remove entire stalks. This opens up the center of the plant, improving air circulation and allowing sunlight to reach new shoots. A crowded clump is more prone to pest and disease issues.
As a general rule, you can remove up to about one-third of the total clump at one time without stressing the plant to much. If your plant is very overgrown, you might need to do this over two seasons.
Step 4: Clean Up and Use Your Cuttings
Remove all the cut debris from around the base of the plant. This helps prevent rot and fungal diseases. Now, you can process your harvest!
For the woody base of a harvested stalk, peel away the tough outer layers to reveal the soft, pale core. This part is perfect for cooking. The green, leafy tops you trimmed off are fantastic for making tea or adding flavor to broths.
Pruning Potted vs. In-Ground Lemongrass
The basic method is the same, but potted plants have some special considerations. They can become root-bound more quickly, which limits their growth.
- Potted Lemongrass: Prune more regularly to control size. If the clump is extremely dense, consider dividing the plant every couple of years in the spring. This involves lifting it, splitting it into sections with a sharp knife, and repotting.
- In-Ground Lemongrass: These plants can grow into large clumps. Your pruning focus here is often more on harvesting and preventing them from taking over too much garden space. They may also need dividing every few years to maintain vigor.
Common Pruning Mistakes to Avoid
Even with good intentions, it’s easy to make a few errors. Here’s what to watch out for.
- Pruning Too Late in the Season: Cutting back in fall stimulates new growth that will be too tender to survive winter cold.
- Using Dull or Dirty Tools: This can damage the plant and spread disease. Wipe blades with rubbing alcohol before moving to another plant.
- Cutting All the Green Growth: Never remove every green stalk. The plant needs leaves to photosynthesize and create energy for regrowth.
- Not Pruning at All: This is the biggest mistake! An unpruned plant becomes a tangled, woody thicket with little usable harvest.
What to Do After Pruning
A little post-prune care ensures a strong comeback. Your plant will appreciate the attention.
Water the plant deeply after a major pruning session. This helps reduce stress. You can also apply a balanced, slow-release fertilizer to support the burst of new growth. Keep the area weeded so your lemongrass doesn’t have to compete for nutrients.
In colder climates, if you’ve pruned in late winter, be prepared to protect new shoots from a late frost with a row cover or by moving pots indoors temporarily.
FAQ: Your Lemongrass Pruning Questions Answered
How often should I prune my lemongrass?
Do a major prune once a year in early spring. During the growing season, you can harvest stalks lightly every few weeks as needed.
Can I prune lemongrass in summer?
Yes, summer is fine for light pruning and harvesting. Just avoid heavy cutting during extreme heat, as the plant is already under some stress.
Why is my lemongrass turning brown after pruning?
A little browning on the cut end is normal. If entire stalks are browning, you may have cut to much at once or pruned at the wrong time. Ensure the plant is getting enough water after pruning.
Should I cut back lemongrass for winter?
In areas with frost, you can cut it back to about 6 inches after the first frost kills the foliage. This neatens the plant for winter. In warmer zones, you don’t need to do this.
How do I prune lemongrass to make it bushy?
Regular harvesting of the outer stalks from the base encourages the plant to produce new shoots from the center, resulting in a fuller, bushier clump over time.
Can I grow new plants from the cuttings?
Absolutely! The best method is to place a stalk with a intact base in a glass of water. Roots will sprout in a couple of weeks, and then you can pot it up. Not all pruned stalks are suitable for this, though—choose healthy, firm ones.
Pruning lemongrass is a simple, rewarding task. With these clear steps, you can keep your plant vigorous and ensure a steady supply of fresh stalks. Remember, the more you harvest correctly, the more your plant will grow. Your garden and your cooking will both benefit from this easy routine maintenance.