A Luffa is a tropical & subtropical vining plant related to pumpkin, squash and gourd. It is grown and eaten as a vegetable, but must be harvested at a young stage of development to be edible. The vegetable is popular in India, China, Nepal, Bhutan, Bangladesh and Vietnam. Luffa is a very popular food item. There are various ways to prepare it including in soups or stir frys. Think of them as tropical courgettes.

When you let the fruit grow till its fully ripened, it becomes very fibrous. The fully developed fruit is the source of the loofah scrubbing sponge. Not to be confused with the sea sponge that is more like an animal than a fruit. This makes using a Luffa also vegan.

So, how do you actually grow your own, plant based, plastic free sponge?

*any links to products are just that, things I use and have bought, they are not affiliated

Lets talk seeds first. They are either a creamy white or matte black. They have a smooth end and an end that looks like it has a little bowtie or looks “pinched”. I’ve been very fortunate enough to have grown luffas successfully for 3 years now. This year my 3 plants yielded 7(!) luffas! They even managed to ripen on the vine. And in case anyone tells you that you can’t grow from white seeds cause they wouldn’t be fully matured or anything, its rubbish, I’ve grown mine from saved, white seeds – and with 100% germination rate at that. This year (2024) I grew my luffa plants from “old 2022” seeds. They were still great.

I tend to start my luffa seeds in February as it has quite a long season for it to grow. I usually aim to start my seeds round Valentine’s day to give them the best head start. You can use heat mats and grow lights, I personally don’t use those and grow them just fine without. Just make sure that at the first germinating stage they’re kept warm. After that warmth and light is key. Let’s get to it!

You’ll need:

• Seeds (4-8 depending how much growing space you’ve got – I can plant 4 in my Ikea pot with metal obelisk, links for both in the section below)
• Nail clippers or sharp scissors
• Damp (warm) kitchen roll paper
• Ziplock bag or lidded plastic tub
• Warm spot indoor (warm airing cupboard is best or sunny window sill above a radiator, or your heat mat – remember, these are tropical plants so we want to mimic their natural growing conditions to the best we can)

1. Clip the smooth end of the seed, only a thin slither is needed. This is to let water get inside the hard seed shell and helps speed up germination.
2. Next put your clipped seeds in the damp kitchen roll and put inside your ziplock bag. Close it up and put in a warm spot
3. Check next day or day after to see if the seeds have germinated. Once you see seed roots and/or even some leaves poke out it’s time to plant them up into soil.
4. Use a 9cm pot (or a little bigger) and fill in with soil. Poke a hole with your finger and place the sprouted seed/seedling root down into the hole.
5. Gently press the soil and firm in & around the seedling and water well.
6. Keep indoors in a warm and sunny spot (a dome or upside down clear plastic tub can help create a mini greenhouse effect)

Tip: Try not to handle or touch the roots. They are very sensitive and fragile. Where possible use the seedling leaves or the actual seed casing to handle your seedling.

*More info for the plant profile check here -> Luffa Plant Profile (opens a new tab)

Once your seedlings have grown several true leaves

You’ll need:

• A big pot or space in a greenhouse in the ground (I use this one from Ikea  ~I’m planning on growing luffas outdoors and inside the house next year as well to – hopefully – show you can grow these things anywhere ~
• Peat free compost (the above pot can take just about 40L compost)
• Support structure like an obelisk (I use these or similar) or bamboo & sturdy string

1. In a large pot place an obelisk, or make one out of bamboo canes and strong string, and fill it with soil
2. Plant out your seedling*, I like to do it by each vertical of the obelisk so that the tendrils (little “arms” the plant grows to cling onto things) have a support at the ready
3. Whilst the luffa vines are growing, train your luffa plants up and around the obelisk. I tend to go one up, then left (or right) until the next one up. This makes the most use of your supports.
4. Keep in a warm and sunny spot, greenhouse is best or bright sunny & warm space in the house should be fine too (like a conservatory) – luffas are, after all, a tropical plant so you want to create as close as you can to its natural surroundings.

*Tip: When in doubt, it is best to wait until the last frost date has past in your area before you plant them outside. Greenhouse should be fine but you may want to fleece them if the night temperatures are still below 10°C degrees – this is based on my experiences in South Devon, every garden has a different micro climate

Luffa is a self pollinating plant, meaning that one plant produces both female and male flowers. As soon as there are flowers you will find 2 different kinds, both yellow with the female flowers having the fruit behind the petals whereas the male flowers just have a thin stem attaching them to the vine. The male flowers are usually in a small cluster grouped together, the female flowers are alone on the vine. To help things along and make sure you will have a luffa fruit growing, it is advised to help with the pollination.

• To make sure you have a pollinated fruit which will grow into your sponge you can help the process by taking the pollen from the male flower (stamen) and put them on the female flower (pistil)
• You can use a soft paintbrush or simply pick the male flower and rub the pollen onto the female flower’s centre
• Pollinators can come in and pollinate your flowers, but, it is no guarantee, by doing it yourself you can be pretty sure you’ll have a pollinated fruit.

Some fruit won’t take regardless of what you do to them, this is not your fault, it just happens. Sometimes you’ll only have male flowers for a week and no female flowers – or in reverse, this also just happens. Be patient, both types of flowers will come at the same time at some point, I promise.

once the fruits have set make sure to water your plants regularly, they’re thirsty plants and have a lot of growing to do. It can definitely help them along if you feed your plants a liquid seaweed feed once a week when they start to set fruit.

When your green fruits are mature & ripe, you ideally let them dry out on the vine. Stop watering the plants completely as this will prevent the drying process (the plant will try to keep them growing or even produce more flowers and mini fruit, these won’t stand a chance as it’ll be too late in the season for them to reach maturity), you want the plant to die back and dry out. I usually start this process something in the second half of September or beginning of October.

• Once fully dry, the luffa will have a hard crispy golden brown shell and when you shake the fruit you can hear the seeds rattling around in it.
• Gently squeezing the fruit may make a crackling crunchy sound
• Once you pick your ripe luffa off the vine you get to peel it! Peeling is the fun part and the reward of all your hard work.

1. Simply gently make a dent in the bottom (there where it had the flower) with your fingers and peel it off
2. Next you can now peel the skin off, some of it will come off as a whole, sometimes in little bits & stringy, just keep going
3. Make sure you remove all and any seeds that are in your luffa. There will be loads! And more again will come out during the washing process
4. Next up is washing your luffa sponge. I tend to rinse mine under a running tap first whilst squeezing out any excess juices, flesh and seeds
5. Then wash it with some soap like fairy liquid and rinse very well after until clean water comes out
6. Let your sponges dry out fully before doing anything else with them
7. Place on a clean & dry new towel and let them dry out completely or hang them up, somewhere with good ventilation and out of direct sunlight

In the event that your luffa doesn’t ripen on the vine or stays green and is still pretty hard, you can still get a sponge! Please note that this method is for hard, green, unripe in any way luffas. Ones that have any give in them need to be handled a little differently.

What do you have to do;

– Cut off both ends of the unripe luffa, just the tips but enough so that you can look inside and see the dense flesh of the fruit
– Cut a slit along the length on one side of the luffa
– Place in a preheated oven between 100-120°C for about an hour and a half (90 minutes)
– At this time it’ll start to smell like a baked potato and should be soft to touch
– Take it out and leave to rest & cool for about 15-20 mins (you’ll burn your hands otherwise)
– Once cool enough to handle you can peel your luffa
– Wash thoroughly to remove any leftover flesh and seeds and dry as described above

My neighbour has grown luffas outside in her south Devon garden and has an unripe luffa currently sat in my greenhouse. Should the heat in there not do anything quick enough I’m going to stick it in the oven and do the above described method to help her get her sponge ☺️

*Main photo is of my neighbour’s luffa that got accidentally mistaken for a large cucumber. It’s rock hard and i’ve put it in my greenhouse to help the drying out along. I checked a few days later and so far so good!

The options are (almost) endless. But to name some of my favourite ways to use them up;

1. You can use them as they are in the shower (they’re great for lathering soap foam due to their fibrous structure) as a big sponge
2. You can cut them into little disks and use them in individual soap making, great to give as a little gift or hand out to guests when they stay
3. You can carefully cut them open and cut the centre support/spine out, fold & sew it together like a square and you’ve got yourself a little dish sponge
4. Some people even sow the little square sponges together to make nesting pads for their chickens! (have a look at Bree’s creative ways @itsbreellis)

I mainly use mine in a little soap as an exfoliator in the shower, the longer bigger chunks (or whole ones) as a bath sponge, and the flat square version for some dishes (like glasses).
The beauty of these things is that they don’t rot whilst you’re using them and once they’re tired and worn – I have yet to reach that point – they can go straight into the compost heap and get worked into compost that can eventually feed new luffa plants! Growing your own sponges is a sustainable alternative to shop bought sponges and once you’ve got your own sponge harvested, you’ll have seeds for the year after and after and many years to come. You’ll never run out of sponges again 😆

Good luck and let me know how you get on growing your own luffa sponges. Find me on instagram via @cornerstonegardenlife and feel free to ask any questions, should you have any ☺️