Is Lemongrass An Annual Or A Perennial?

Lemongrass is a relatively easy-to-grow plant that you can grow either as ornamental grass or a culinary herb. Many people use the lemongrass stalks in Asian cooking, and the leaves can be used to make tea. Lemongrass also contains citronella, so it’s great for repelling insects.

Lemongrass is a tender perennial. That means it will grow for many years, but it is not frost-hardy. So, in areas that get very cold winters, the plant will not survive outside and must be replanted the following spring. People who live in USDA zones below 8b need to treat this plant as an annual.

However, if you grow lemongrass in a pot, you can simply bring it indoors before the first frosts hit.

Is Lemongrass An Annual Or A Perennial?

Lemongrass is a tender perennial. In areas that have only mild winters and no frosts, lemongrass can be left in the ground all year round, and it will continue to grow for many years. This is because lemongrass is a tropical plant and is native to the warmer regions of Australia, Africa, and Asia.

Most tropical plants do not cope with very cold weather, and lemongrass is no exception. In areas that experience frosts during winter, the lemongrass will simply die and will have to be replanted once the soil warms up again.

So, depending on where you live, lemongrass will either grow happily as a perennial, or you will have to treat it as an annual.

MokkieCC BY-SA 4.0, via Wikimedia Commons

As a quick guide, here’s what you can expect your lemongrass to do depending on where you live in the US.

  • USDA zones 10 to 11 – lemongrass will grow as a perennial and will remain green all year round.
  • USDA zones 8b to 9 – the leaves of your lemongrass will die down but the roots will survive the winter and new leaves will start to grow in the spring.
  • USDA zones below 8b – lemongrass will not survive the very cold winter temperatures and will need to be replanted in the following spring.

So, as you can see, even though lemongrass is technically a perennial plant, its survival depends entirely on the climatic zone that it’s grown in.

However, if you do live in a cold region, there is a solution. In this case, you can simply grow your lemongrass in pots and then bring the plant inside before there’s any danger of frost. As long as you give the plant plenty of bright light and ensure that the temperature doesn’t drop too low, your lemongrass will survive. Then, once spring arrives, you can take the plant back outside again.

Bear in mind, though, that a plant that has been growing outside in the warm sun may not look as healthy and lush once you bring it inside over winter. But don’t worry. Once the weather warms up again, and you can take your plant outside, it will spring back with new growth fairly quickly.

How To Prepare Lemongrass For Winter

Depending on where you live, there are certain things that you can do to prepare your lemongrass for winter. Let’s look at these in relation to your climatic zone.

USDA Zones 10 to 11

If you live in these zones, there’s nothing you have to do to prepare your lemongrass for winter because temperatures will not drop too low. However, during the winter months, your lemongrass will not require feeding or as much water. Thus, you can resume fertilizing your plant again in spring as it starts to put on new growth.

USDA Zones 8b to 9

To help your lemongrass deal with the colder temperatures during winter, you should cut back the foliage in late fall. Then, cover your plants with a thick layer of straw or similar mulch. This will help to keep the roots a little warmer and will mean that your plants will spring back to life once the ground starts to warm up again.

USDA Zones below 8b

If your lemongrass is already growing in a pot, you will need to condition it to living indoors. You need to do this before the first frosts arrive.

During the fall, simply bring your plants in during the night and then take the pots back out during the day. Try and do this for at least a week or two before the first frost. Then, when temperatures are predicted to plummet, make sure that you keep your plant indoors both during the day and the night.

Place your lemongrass in a nice, bright window that lets plenty of light in. Water it only when the top inch of soil feels dry, and don’t give it any fertilizer during this time. Then, in early spring, when the danger of frost has passed, you can reverse the process to recondition your plant to living outdoors again.

In the beginning, place the plant outdoors during the warmer parts of the day for a few hours and bring it back in overnight. Increase the amount of time that the plant stays outdoors day after day until finally, you can leave it outdoors right throughout the warmer months.

If you would like to know more about growing lemongrass in cold climates, I wrote an entire article about it.

In Cold Climates Divide Some Plants And Pot Them Up

If your lemongrass is growing in the ground, it’s going to die once the cold winter frosts arrive. But, you can save some of your plants by propagating some of the offshoots and planting them in pots.

To do this, first cut the leaves down to a height of 2 inches (5cm). Be sure to wear gloves when you do this because the leaves have very sharp edges. Dig up one of the plants and then divide it into 6-inch (15cm) sections. Make sure that each section has some healthy roots attached.

Plant each section into a deep pot that is at least 12 inches in diameter. If the roots are very long, you can gently trim them a little so that they will easily fit into the pot. Water well and place the potted lemongrass in a warm spot for a couple of weeks if you can.

Then, condition your plants to indoor life by bringing them in overnight and taking them out during the day. Finally, keep your plants totally indoors, making sure that you place them in a brightly lit spot that remains warm.

How To Care For Lemongrass During The Winter

In general, lemongrass really doesn’t need much extra care during the winter other than following the instructions above. Your plant will not require very much water and doesn’t need to be fertilized over the colder months.

However, if you’ve brought your lemongrass inside to overwinter it, you may need to provide the plant with some extra humidity. If you run your heating continuously, you’ll find that the air becomes fairly dry. As lemongrass is a tropical plant, it does like a fair bit of humidity.

You can give your plant additional humidity by either using a humidifier or placing the pot on a tray filled with pebbles and water. This way, the water will evaporate and create additional humidity around your plant. And, because the pot is sitting on the pebbles, the roots won’t be in constant contact with the water.

If you would like to know everything about growing lemongrass, check out this article that I wrote on the topic.