Gardeners' World expert Frances Tophill has shared a top tip for growing lemongrass, a plant that thrives in hot weather, by propagating it from supermarket cuttings.
2026 has already seen more days exceeding 30C than the entirety of 1976, a famously hot year. Based on Met Office data, this marks the first year on record where temperatures have hit 35C in May, June and July, while overnight temperatures have been reaching record highs for this point in the summer.
How to propagate lemongrass
"Lemongrass is a great one to grow because you can propagate it by cutting, and you just do that in water," she says. "It's time of year dependent, so I wouldn't do it in the winter, but when the weather is warm, they'll go quite quickly."
In the latest episode of the BBC Gardeners' World podcast, she reveals that when you purchase a stick of lemongrass from the supermarket, it will typically include its basal plate, which means it's relatively simple to propagate at home.
If your lemongrass has that basal plate - readily recognised as a slight bulge at the base of its stem - it will be remarkably easy if you just place that directly into a glass of water on the windowsill, somewhere warm, two or three weeks will be sufficient for it to begin developing roots.
Growing and harvesting
Once your lemongrass cuttings have established some roots, you can transfer them into a pot. "Pot them all up together and chop them down," Frances says. "Leave about three centimetres above the soil, so you're not completely getting rid of them. But then they'll start to sort of bulk up a little bit, and they do produce little clusters and grow from that."
"If you do that in the spring, you can put that pot outside for the summer, and it will get a really big, healthy growth. They like quite a lot of moisture, and they're not really heavy feeders, but if you give them some feed, then they will get bigger and healthier. You can then either dig them up in the winter and just use it, but I don't know anyone who gets through that much lemongrass."
Rather than harvesting all at once, Frances suggests trimming your lemongrass gradually as and when you require it. Provided you protect it from frost, she notes, it will continue to thrive year after year, ensuring a ready supply of lemongrass whenever needed: "I have lemongrass that's about six years old in my greenhouse, and I can chop it back whenever I want and get fresh, homegrown lemongrass."
Tune in to watch Frances Tophill on Gardeners' World tonight (Friday, July 24) on BBC2 at 8pm.
