By: Liz Baessler
Popular in Asian cuisine, lemongrass is a very low maintenance plant that can be grown outdoors in USDA zone 9 and above, and in an indoor/outdoor container in colder zones. It’s fast growing though, and can get a little unruly if not pruned back regularly. Keep reading to learn more about how to cut back lemongrass.
If given plenty of sun, water, and fertilizer, lemongrass can grow to as big as 6 feet (1.8 m.) high and 4 feet (1.2 m.) wide. Pruning lemongrass plants is a good idea for keeping them a manageable size as well as encouraging new growth.
Cutting lemongrass stalks for cooking will keep the plant somewhat in check, but lemongrass grows so quickly that extra pruning is often necessary.
The best time for trimming lemongrass is early spring, when the plant is still dormant. If your lemongrass has been left untended for a while, it has probably accumulated some dead material. The first thing to do is get rid of that.
Rake away anything that’s unattached underneath, then pull out any dead stalks that are still in the ground. These are probably mostly around the outside of the plant. Once all that remains of your plant is green, you can cut down the tops of the stalks to make it a more manageable size.
Lemongrass is very forgiving and can be cut back quite drastically. Cut it down to as little as 3 feet (.9 m.) high and prune it regularly to keep it that size if you so desire.
If you live in a colder climate, your lemongrass may go dormant over the winter, with all of its leaves turning brown. If this is the case, wait until early spring for lemongrass pruning and cut all the leaves away, right down to the tender white part of the stalk. This may look extreme when you do it, but before long, fresh growth should come in to replace all that lost material.
This article was last updated on
Read more about Lemongrass
Justus de Cuveland / Getty Images
Ornamental grasses are fairly new to the landscape scene—they've increased in popularity in the past couple decades. In regions experiencing drought, native and ornamental grasses are a smart and show-stopping part of the landscape. As more grasses are introduced from other parts of the world that share similar climates, landscape professionals aren't always in agreement on how to handle these exotic imports.
Unlike rose bushes or boxwood hedges, there's not really a tried-and-true method for pruning or grooming ornamental grasses. Not every landscaping pro knows how to take care of everything in the garden, including grasses that can grow quite large—as in tall and wide. Follow these steps to groom your grasses and get them to looking great.
Most ornamentals are easy to grow, requiring little water and fertilizer and no pesticides. They look equally beautiful planted poolside, blowing in the breeze, in containers on patios, and as accent plants in other areas of the landscape.
Look for lemongrass transplants or divisions (learn how to divide lemongrass in tip #6) – this is the easiest way to add lemongrass to your garden.
To start lemongrass from cuttings:
Last Updated: February 12, 2021 References Tested
This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. wikiHow's Content Management Team carefully monitors the work from our editorial staff to ensure that each article is backed by trusted research and meets our high quality standards.
There are 11 references cited in this article, which can be found at the bottom of the page.
The wikiHow Video Team also followed the article's instructions and verified that they work.
This article has been viewed 39,475 times.
Lemongrass is a staple of Thai cuisine and is commonly included in many popular Thai dishes. You can purchase bundles of 2–3 lemongrass stalks in large supermarkets and in any Asian market or grocery store. The grass itself is coarse and thick and needs to be prepared in a specific way before it can be used in food preparation. Once you’ve purchased the lemongrass, preparation shouldn’t take more than 15 minutes.
Most of us know what to do with our big grasses that go dormant each winter: Grab a bungee cord, tie the grass up, and use an electric hedge trimmer to buzz the column of foliage to the ground. But what about those tricky grasses that are evergreen or ones that have a ground-hugging habit? When and how do you prune those garden staples that don’t fit neatly into the “large and goes dormant” category?
If you are hesitant to treat your sedge the same as your maiden grass, it’s for good reason. Unconventional grassy plants can’t be trimmed using generalized pruning rules. They require special timing and techniques on your part to look their best. Start by figuring out which category your grasses fall under: evergreen or goes dormant, large or small. This allows you to select the best pruning method, even if you are not sure of the exact varieties you have.
What: Japanese forest grass (Hakonechloa), Japanese blood grass (Imperata cylindrica), switch grass (Panicum), fountain grass (Pennisetum)
Photo: Before and after pruning Japanese forest grass
When: Yearly, late fall to mid-spring
How: If you like to prune, these short, spreading grasses are satisfying to tackle. Though you can prune any time after they go brown, hold off on cutting these grasses back as long as possible. Even brown, they provide winter interest and act as sculptural sentinels when covered in snow. If you clean up too quickly, you miss a lot of winter beauty. Birds also love to pack and scratch at the seeds in late winter when food is harder to come by.
Depending on your weather though, at a certain point these grasses will start to crumple and look thoroughly messy. When that time comes, use hedging shears to cut these grasses back to a height of 3 inches for the smallest selections – those that are under 3 feet tall, and to 6 inches for taller varieties – those that are over 3 feet tall. If you cut too low, you could be in danger of cutting into the crown of the plant. Moisture then tends to settle into the crowns and rots them out.
While some of these grasses have obvious growth points at the base and can be cut a little lower, others form rounded clumps – and it’s not always clear when you are in danger of cutting into the body of the crown. It’s good to leave a couple inches of leeway and not cut directly next to the growth points so that dew or frost settles a couple inches away from the crown. When I cut too close to the crown, I usually lose a few clumps throughout the plant and need to pull out the rotten bits a couple of months into the season. Pruning should be done every year to give the new foliage a clean slate from which to shine.
What: Maiden grass (Miscanthus), feather reed grass (Calamagrostis), Giant pheasant’s tail grass (Stipa gigantea)
Photo: Before, during, and after pruning Miscanthus
While pruning large grasses that go dormant is a similar process to pruning small ones, there’s something about having a huge mass of foliage towering over your head that makes it seem like a more intimidating task. Plus, bigger grasses can have sharp leaf blades, so if you prune without preparing you can get dozens of tiny stinging cuts on your face and arms.
When: Yearly, late fall to mid-spring Just like with small dormant grasses, it’s best to hold off on pruning as long as possible to preserve the winter interest and to provide food for birds. You can prune anytime after the plants go fully brown, as long as you do so before they start growing again in spring (you don’t want to nip the fresh new growth tips). The grasses themselves will give you your cue. Maiden grasses start shedding soon after the new year, so as soon as you notice them making a mess, it’s time to prune.
How: Even if you choose a sunny day to prune, wear a long-sleeved shirt and gloves so the blades of grass don’t cut your skin. Start by wrapping a piece of rope around the outside of the grass and tie it into a tight column of foliage. This way, the grass will stay bundled as you prune and not explode into pieces everywhere. Once your grass is tied up, use handheld or powered hedging shears to cut the entire grass to about 10 inches tall. If you’re using powered hedging shears, it’s helpful to have a friend hold up the grass so it doesn’t fall on you as you cut. Just be careful not to trim anyone’s ankles!
Though small grasses are easy to clean up, big grasses make a big mess. Plan to put down a fresh layer of mulch after you’re done pruning. This covers any tiny bits of grass that won’t rake up. (More on pruning Miscanthus here and here.)
What: Sedge (Carex), sweet flag (Acorus), blue oat grass (Helictotrichon), Mexican feather grass (Nassella tenuissima), lily turf (Liriope), mondo grass (Ophiopogon)
Top: Getting the brown blades out of blue oat grass Bottom: Mexican feather grass before, a month after, and three months after pruning
These little charmers are some of the easiest plants to tuck into your garden, because they fit almost anywhere, have year-round good looks, and need little care. Yet even the most easy-going of grasses need periodic attention to perform their best.
When: any time for cleanup, early to mid-spring for rejuvenation
How: By the end of the growing season, brown foliage can pile up inside these plants and give them an unkempt appearance. Luckily, there’s an easy fix to clean them up: just put on some rubber gloves (cheap dishwashing gloves work great) and run your fingers through the grass as though you were combing its hair. The spent foliage clings to the rubber and comes out in easy clumps. You may not be able to clean out all the spent blades, but removing some will trigger the grass to refresh itself.
Sometimes, of course, a stronger solution is needed. If painters have trampled on your evergreen grasses or if wind or winter cold have damaged even the freshest leaves, it may be time to go in for the big chop. In early to mid-spring, use your hand pruners or hedging shears to reduce the height of your grasses by two-thirds. While this leaves your grasses looking like awkward hedgehogs, these grasses bounce back fairly quickly and usually look good again in 2 to 3 months.
Cutting these grasses back too much will allow moisture to gather on their crowns, which can cause rot. When I’ve experimented with cutting back more than two thirds, portions of the grass died a soggy death. If you’re overly zealous with the pruners, you could also cut into the growth points on the crowns without knowing it – especially on sedges, which can form a mounded crown.
Rejuvenation pruning shouldn’t be done more than every 2 to 3 years because small evergreen grasses have slightly less vigor than grasses that go dormant. When you cut off all that foliage, the plant is losing energy stored in its leaves, so it ends up with less energy to put into producing new growth. I like to give the grasses time to recover before subjecting them again to a stern pruning. The exception is Mexican feather grass, which can be pruned back hard any time its foliage clumps into unsightly dreadlocks:
What: Flax (Phormium), Cordyline (Cordyline), Yucca (Yucca)
Photo: Before, during and after pruning a Phormium/ flax
Although technically not “grasses”, these large, spiky plants stand as focal points in the landscape, drawing attention with their bold colors in dramatic shapes. This makes it all the more important to prune right, because a poor pruning job will be noticed by everyone. Unlike with large deciduous grasses which are whacked back almost to the ground, subtlety is key when pruning large evergreen “grasses”. There are many reasons to prune these plants, ranging from the removal of dead flowers and ratty leaves, to keeping plants in scale with their surroundings. With brightly colored flax, there’s another reason to prune: The new growth is more brilliantly-colored.
When: Anytime for cleanup and resizing mid-spring for rejuvenation
How: When pruning to freshen up foliage, I simply select the oldest or most damaged leaves and cut them out at the base. This might seem like a time-consuming task, but once you get into a rhythm, it goes pretty quickly. Use the same technique to prune for size. Grasp the tallest leaves, and one by one, cut them out as far down towards the base of the plant as possible. When pruning for size, move around the plant as you go, removing up to two thirds of the leaves, which is the point at which the pruning becomes obvious.
Sometimes, however, selective pruning just doesn’t cut it. If your plant is overgrown, has significant winter damage, or must be cut to make room for construction, you can prune severely in mid-spring. Use hedging shears to cut off all the foliage at the base. You’ll end up with a mound about 1 foot tall. While cutting off all the foliage is not an ideal approach, these varieties grow back quickly and look good again in about four months. They do, however, have an awkward phase during their regrowth: When the blades start to regrow, some will look damaged and have clipped tips, so you’ll need to selectively prune again to remove those. This allows the fresh new growth to shine.
Over time, some varieties of Yucca and Cordyline grow quite tall and develop a long trunk. If you don’t want yours to look like a tree from a Dr. Seuss story book, cut the plant midway down the stem it should pre-sprout from just under the cut point. In areas where these plants are marginally hardy, however, cut the trunk back by only one third. Sometimes that stem will re-sprout, but occasionally, the plant will sprout up from the base, instead. One last caveat: Be sure to wear eye protection any time you are pruning spiky grass-like plants. When you are focusing on removing leaves at the base, it’s easy to lean down and get stabbed in the eyeball with a sharp leaf tip. That’s a definite pruning “don’t”.
(Article originally appeared in Fine Gardening Magazine)
Genevieve Schmidt is a landscape designer and owns a fine landscape maintenance company in Arcata, CA. The owner of North Coast Gardening, she is also a contributing writer at Garden Design Magazine and has written for numerous print and online publications.
oh-my-goodness-Jen – This is so helpful. All the answers in one place. I’m bookmarking this one!