22 March 2021

How to grow your own loofah

22 March 2021

They’re best known as back scrubbers, for use in the bath or shower, but loofahs are also tipped to be among the must-have plants to grow this year, in an effort to help ditch unnecessary plastic.

“When you mention ‘loofah’ to people, 90% of people think they’re a sponge that grows in the sea,” says Rob Smith, product development manager for Suttons (suttons.co.uk) and a keen grower himself.

Suttons launched Luffa (that’s the botanical spelling) cylindrica seeds in September. They should be sown between January and March, but the company will also be selling plug plants in April and May for people who missed the sowing period and still want to have a go. “There are so many newcomers to gardening and a lot of them are looking for something different to grow,” observes Smith.

So how do you go about growing them? Smith explains…

Which family are luffas from?

They are a gourd, native to south and southeast Asia and are grown in conditions similar to greenhouse cucumbers.

What conditions do they need?They need warmth, so you’ll need a heated greenhouse or suitable windowsill on which to sow the seeds or grow the young plants. They can take two or three weeks to germinate. Ideally the seeds should be sown in a heated propagator, or a warm spot on a windowsill.

Pot them on, adding pea sticks or canes for the tendrils to grab on to as they grow, until you can transfer them to an unheated greenhouse when all danger of frost has passed, in late May or early June.

If they seem to be growing too quickly in your home before you can transfer them, you can slow them down by leaving them in their pots, so their roots are restricted.

How long do they take to grow?

It’s a long season. Once the plant starts growing, it grows quickly, but can be cut back if it gets out of control. They can grow extremely tall – to more than 10ft – and will fill any space you give them.

I grow them in big pots of multipurpose compost, as I would do cucumbers or tomatoes, but they’ll need to be spaced around 45-60cm apart. They will grow into each other.

Do you need to prop them up?

Yes. They will need netting, canes or wires to climb up, but they won’t need little hammocks underneath them, as you would with melons, because the stem is quite tough and as they become more fibrous, they get lighter.

What about pollination?I leave my greenhouse doors open in the day and then close them at night, so the insects will have done their work.

Can you eat them?

Yes, they are just like a climbing courgette or pumpkin. The foliage looks more like a fruit, but the luffa has a beautiful big yellow flower the size of the palm of your hand, a bit like a courgette flower but a bit more dainty.

The first few flowers don’t set, but once they start setting you can eat them, until they are 5-6in long, using them like you would a courgette. They look like courgettes, although they are not as smooth-skinned, and are lighter than a dark courgette.

How do you maximise the crop?

Luffa fruits on the vine (Rob Smith/PA)

If you want to eat them, harvest them small. Leave, say, three to grow on each plant to become the big luffa. Once they reach more than 6in long you wouldn’t want to eat them because the inside starts to form the fibrous skeleton.

As it develops, it starts to look almost like a marrow. If you grow them well they can be as thick as your forearm.

How do you know when the luffa is ready to harvest?

Leave it on the plant until the plant starts dying back in late summer and early autumn, when the foliage starts to go brown.

The luffa will start to go to a brown-khaki colour and you see it physically dehydrating as the skin wrinkles and the fruit becomes light. Cut them off and leave them in a dry shed to dehydrate a bit more, then when the skin is almost crispy you can peel it off or submerge them in a bucket of water which helps the skin come off more easily.

Then you have your luffa, but you need to shake it to remove the hundreds of seeds inside. Its natural colour is off-white, as the pure white ones you see in shops have often been bleached.

What can you use it for?

Obviously, you can use it when you have a bath or shower to exfoliate and remove dead skin, but you can also slice it thickly into rings and use it as pan scrubs instead of metal or plastic-based pan scourers. Some people even fill the thick-cut luffa circles with home-made soap and give them as Christmas gifts.

How do you dispose of them?The whole plant and spent luffas can be put on the compost heap where they will degrade naturally.

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