Growing lemongrass is both easy and rewarding. This delicious herb is not only delicious in all types of Asian cooking, but it’s also quite an attractive ornamental plant. For landscape planting, you might be wondering how tall lemongrass grows.
Each lemongrass clump can reach a height of between 3 feet (0.9 m) and 6 feet (1.8 m). However, it’s also possible to trim down lemongrass if you’re finding that it’s getting too tall for its location.
Here are some tips on what you can do to keep your lemongrass from getting too tall.
Give Your Lemongrass A Regular Prune
Like most clumping grasses, lemongrass can be kept in check with a regular prune. This will not affect the health of your plant, but it will ensure a nice even shape and a beautifully trimmed plant.
Even when you harvest the stalks regularly, because lemongrass grows so quickly, you will find that regular trimming is necessary to keep your plant in check.
The best time to cut back your lemongrass is early spring, while your plant is still dormant. This is, of course, assuming that your lemongrass is growing outdoors and you live in an area that doesn’t receive winter frosts.
Before you start trimming, it’s a good idea to clean up your plant by removing any dead material that may have accumulated over winter. Make sure that you always wear gloves when tending your lemongrass to avoid nasty cuts to your fingers.
You might find that there are some dead stalks, primarily around the edges of your plant, that you can easily pull out. Once that is done, and there’s only green plant material left, you can begin the trimming process.
You might be surprised to learn that you can cut your lemongrass back quite drastically, and it won’t harm the plant at all. With a sharp pair of grass shears or hedging shears, just cut off the top foot or two of green growth.
Cut the tops of the leaves straight across until they’re all the same height. You can easily cut your plant down to around 3 feet (0.9 m) or, basically, take off half of its top growth.
After this, it’s just a case of giving the top of your plant a regular trim to control the height and keep the nice trim shape.
How To Prune Lemongrass Growing In A Colder Climate
If you live in a colder climate, but your lemongrass is growing outside, it has, most likely, gone dormant over winter. This will have caused all the leaves to turn brown.
If this has happened, in early spring, you can cut off all the old growth right down until you see the tender white part of the stalk. Don’t be afraid to do this, although it might seem a little extreme.
Once the weather starts to warm up, you’ll soon see fresh new growth starting to appear. Then, over the warmer months, if the growth starts to get too tall, you can simply trim it back with a pair of shears.
This allows your lemongrass to put all its energy into producing new stalks that you can harvest to use in your cooking.
If you live in USDA zones 8b to 9, cover the entire plant with a thick layer of straw mulch over winter. Alternatively, you can use a frost blanket. This will protect your plant from any unexpected frosts and ensure that it will come back again in the summer.
Then, once the temperatures start to rise in early spring, pull back the mulch or the frost blanket and cut back the dead leaves as mentioned above.
If you would like to know more about growing lemongrass in a colder climate, check out this article that I wrote on the topic.
What To Do With Lemongrass That Is Growing In A Pot
The same rules apply for trimming lemongrass that is growing in a pot. Whether you have it outdoors or bring it inside over winter, your plant can still be pruned and trimmed regularly to stop it from getting too large.
If you’re in USDA zones 8b or above, you can happily leave your pot-grown lemongrass outdoors over winter. However, if you live in a colder zone, you’ll want to bring it indoors over the colder months.
Remember that lemongrass will go dormant over the winter period, so it doesn’t need a lot of light or water.
The best time to trim back your lemongrass is either as soon as it becomes dormant or in early spring, just before it comes out of dormancy. Trimming your plant before the winter makes it easier to bring indoors and keep it in a dimly lit room with a temperature that’s above 50 degrees Fahrenheit (10 degrees Celsius).
Your plant won’t grow during its dormant period, so you won’t have to do much to keep it alive. Once the weather starts to warm up again, you can give it a good clean-up to remove any dead foliage and place it back outside again.
Remember to harden off your lemongrass that has been living indoors over winter. To do this, just put it outside for a couple of hours, to begin with, during the warmer parts of the day. Then, increase the amount of time that you leave it outside day by day until you can leave it out all day and night.
Summary Of When To Trim Your Lemongrass Depending On Your Climatic Zone
Here’s a quick summary of when and how to prune your lemongrass, depending on your climatic zone.
USDA zone 10 and above – Give your lemongrass a hard prune in early spring, cutting back up to half its top growth. During the growing season, continue to lightly trim the top of the plant to keep it contained and neat.
USDA zones 8b to 9 – In early spring, remove all the dead foliage by cutting your plant back down to the white stalks. During the warmer months, keep your plant trimmed to control its growth and keep its shape.
USDA zones 7 and below – Trim back the top growth of your lemongrass in the fall and bring it indoors to overwinter. In early spring, cut back any dead foliage and harden your plant off to go back outside again. During the summer months, keep the top of your plant lightly trimmed to control its growth and shape.
Lemongrass Grown Indoors All Year Round
If you’re growing your lemongrass indoors in a pot all year round, you want to ensure that you keep it nicely trimmed. You can do this all during the growing season, as it’s not likely that your plant is going to get out of hand when it’s in full view all the time.
Just keep trimming the tops of the leaves as the plant grows. You can use these to make lemongrass tea. This will keep your plant in check and will ensure that it keeps producing more of those tasty stalks.
During the colder months, it won’t be necessary to do much trimming because your lemongrass won’t be growing much anyway. Then, once you start to see new growth in the warmer weather, you can continue to trim your plant on a regular basis.
If you would like to know more about growing this perennial grass, please check out the complete guide I wrote about growing lemongrass.