Wanna learn how to grow a Luffa? Yeah. So did I. So when I figured it out I thought … I’d better tell you exactly how to do it too. This year I’ve added WAY more information (and tips) to this post with a few new things I’m going to try myself.
As a matter of fact, no they do not grow in the ocean. Or the sea. Or any other body of water. That’s always the biggest shock to people when you tell them they can grow their own luffa sponges; the fact that they grow on land, not in the water. You’re thinking of Spongebob Squarepants.
A bit about the Luffa.
- Luffa, Loofah. All the same thing just different spellings.
- Luffas are part of the gourd family and grow on vines that can get to be 30′ long. Trust me on this.
- The part of the Luffa you’re used to seeing is actually the inside fibres of the gourd, which lay beneath the green skin.
- Immature Luffas look pretty much like a cucumber or zucchini and can be eaten when they’re very young (4-8″ long).
- Luffas turn brown and become light as a feather when they’re ready to pick but if there’s a danger of frost you can pick them earlier (like I did).
- Luffas are shitheads.
For the past decade or so I’ve been killing myself trying to figure out how to be completely successful growing luffa in my zone 6 climate. Luffa need a longggg growing season and they also seem to be easily frightened. Like you can frighten a Luffa to death. More on that in a few moments.
To figure out how to successfully grow a Luffa sponge, you have to know how to very, very unsuccessfully grow a Luffa sponge. Luckily for you, I have all kinds of experience in that particular area. In fact, I’ve spent the better part of a decade being really great at unsuccessfully growing Luffa sponges. Not to brag.
There are 3 main areas where things can go horribly wrong.
- Your seeds won’t germinate. Because they’re little asshead seeds that hate you.
- Your little luffa seedling goes into shock when you transplant it outside and it dies of fright or at least goes into a month long coma.
- Your vine grows but you never get to the point of seeing fruit before the frost kills it.
I’m going to show you how to overcome all of those issues so you can grow your very own organic Luffa sponge this summer.
Handy for showers, scrubbing pots and whacking people on the head with.
So how can you overcome these obstacles so that you can proudly peel your very first luffa sponge? These few simple tips are the only thing between you and a Luffa.
HOW TO GROW LUFFA (LOOFAH) SPONGE
- If you’re in a cooler zone, start your Luffa seeds early, indoors, 6 – 8 weeks before the last frost date.
- Use new Luffa seeds and soak them in water for 24 hours prior to planting. Seeds that have been hanging around for years probably won’t germinate.
- Increase your success at germination by starting your seeds on a seed heat pad.
- Transplant into biodegradable or paper pots once the first “true” set of leaves have formed. Using pots that decompose reduces the risk of transplant shock which Luffa plants are prone to.
- For an even BETTER chance of reducing transplant shock, grow in soil blocks instead of pots.
- When the weather is right (warm soil and air) start hardening off your seedlings. This is more important than with most other plants because Luffa are so prone to transplant shock.
- After a week or so of hardening off, plant your seedlings in an area that gets FULL sun. As much sun as possible. Anything less and you won’t get any Luffas.
- Plant your seedlings at the base of a really strong structure that its vines can climb on and cling to. Chain link fence or something similar is perfect.
- If after planting out, a cold snap threatens, cover the seedlings with a vented cloche. A plastic pop bottle cut in half with a lot of air holes punched into it would work fine. A few days of cold weather will STOP a luffa from growing and it could take a month before they get over the shock.
- Keep the Luffa watered. No water equals no growing! Now you wait. And wait. And wait.
- 2 months before your first frost date (by the early middle of August for me in zone 6) you need to pinch away all the flowers on the vine. This is important because it will direct all the plant’s remaining energy to growing the luffas that are on the vine now instead of starting all new tiny luffas from the flowers that have no chance of ever getting big enough to harvest. THIS IS CRUCIAL.
- By October you should have big, green Luffas. Pick your Luffa sponges BEFORE they’re hit by frost even if they’re still green. Technically you aren’t supposed to pick them until they’re dried out and brown, but in Zone 6 it’s rare for them to get to that stage. You can still pick them when they’re green and get perfectly acceptable Luffas. They’re just a bit harder to peel.
To increase your chances at success even MORE try growing your luffas in a little hoop house/low tunnel like this:
- Build a small hoop house and cover it with 2 layers of 5 or 6mm plastic. It only needs to be 1-2 feet high.
- Heat the hoop house with a single lightbulb.
- After your seeds have germinated in your house immediately put them into the heated hoop house remembering to monitor it every day and vent it on sunny days or when it starts to get warm.
- When the soil is very warm and it’s nice out (for me that’s June 1st) plant your luffa seedlings in their final location.
A fellow luffa grower in my area starts and grows her luffas like this and has had HUGE success. I’m going to try it myself this year with half of my luffa plants.
This is what my luffa plant looks like when it’s starting to grow. You should expect this much growth after about a month in the ground outside.
By the end of the season the luffa plants will fill the entire fence. They’re had to spot in the photo below but to the right of the straw umbrella you can see the wall of luffa green climbing up the fence with the odd yellow flower at the top of it.
Like I said, it isn’t easy and definitely not for the half assed gardener. But if you really want to grow luffas where you have a shorter than ideal growing season, YOU CAN.
I’ve been getting full sized luffas from my zone 6b garden for years now, always picking them in October when they’re still green. If you read any other article on Luffa sponges that tells you you’ll only get a useable sponge from a Luffa that’s dried to a dark brown on the vine don’t believe it. It ain’t true.
There’s a bit of a funny story behind picking my Luffa sponges this year actually.
It was Thanksgiving at my house and all but 2 of the dinner guests were slouching in the family room waiting for the turkey to hit the table and the last 2 guests to arrive. I went in to check to see if anyone needed anything and everyone in the room happened to be discussing the weather. Because we’re Canadian. And not especially well versed in politics. Apparently there was going to be frost that night.
WAIT?!!! [email protected]!!! TONIGHT??!! THERE’S GOING TO BE FROST TONIGHT??!!!! SHITMOFARKLESPARX!!
And out the door I went, my bewildered Uncle Jack in tow, whizzing past the last 2 guests who were just pulling up.
B E B A C K L A T E R !!!!!!!
In the middle of hosting Thanksgiving dinner I left all of my guests in my house and dragged my Uncle up to my community garden, a 5 minute drive away, to pick all of my Luffas. They weren’t dried and brown on the vine yet but I knew if they got hit by frost they’d be ruined. They’d either turn to “ick” or they’d become all discoloured inside. Since we were already there I figured I might as well pick the rest of my tomatoes, kale, green beans, jalapenos and red peppers. Since we were there.
In an ideal world Luffa gourds will become around 24″ inches long and go from dark green, the light green, to yellowish, to completely dried out, crispy and brown on the vine. But if your growing climate isn’t long enough, you may just end up with vines covered in dark and light green gourds, which is what I end up with.
I used to think it was best to let them dry for a month on the front porch after picking them but I WAS WRONG. It’s better to peel those suckers right away. Leaving them could lead to rot inside and discoloured luffa sponges.
To your amazement, underneath all that luffa skin and guts you will find an actual sponge.
The green skin is hard to get off but with with my stubby, bionic, man-baby thumbs I managed quite nicely.
Two of my 6 Luffas this particular year had matured enough that the seeds inside were big and dark. THESE are the perfect seeds for saving for planting.
Seeds that are light and haven’t matured inside the plant enough won’t be viable and won’t grow plants. The seeds you see below aren’t ideal for planting and 98% of them wouldn’t produce a plant with the exception being the few very dark seeds in the bunch.
So let’s talk about how to plant your seeds and WHY a seed heat pad is so important to successful germination of Luffa seeds.
For the first several years that I planted my Luffa seeds I would plant them, keep them watered and wait. Nothin’. I got nothin’ for over a month. Then maybe one would sprout. Or 3. Or none.
Since 2017 I’ve been starting my luffa (tomato, pepper and other heat loving seeds) on heat pads.
Luffa seeds like a lot of consistent heat to germinate and grow. I figured the $20 it cost for the seed heating pad would be worth it if it would guarantee germination.
And it did.
I started 2 pots with fresh Luffa seeds. I set one pot on the heating pad and one on an unheated tray.
The seeds on the heating pad germinated within 3 days at a rate of 100% (all 6 seeds sprouted). The seeds that were unheated germinated in 10 days at a rate of 50% (3 seeds sprouted).
I kept the seeded pots in their respective places as they grew and the heated seedlings grew at twice the speed as the unheated ones.
If you’re serious about growing your own Luffa buy the heated seed pad. It also happens to be the perfect size for sitting an entire seed tray on so you can use it to increase the germination rate of other seeds that like bottom warmth to germinate like tomatoes, asparagus, peas and peppers.
It’s also working GREAT for my Sweet Potato slips using my updated sweet potato growing method.
Once your Luffa seedlings have their first “true” set of leaves (the leaves that look like the leaves of the actual plant, not the first set of leaves which are just practice leaves basically) you can transplant them into their own pots.
UPDATE: LUFFA ARE SO VERY sensitive to root disturbance that I now grow them in individual pots so there’s no need to separate them. And this year I’ll be doing them in soil blocks.
Gently separate the seedlings and plant them in either store bought biodegradable pots or make your own newspaper pots like I show you here.
Biodegradable pots can be planted right in the ground making the very, VERY finicky Luffa plant less likely to go into transplant shock. BUT biodegradable pots don’t biodegrade very quickly, making it difficult for plant roots to get out into the soil that they need to.
Newspaper pots or growing in soil blocks is a better option.
Don’t have a big vegetable garden? No problem. You can plant Luffa plants in a big pot or even better, grow bag. Make sure it’s big enough though.
Size sized pot for a luffa plant?
You’ll need a 25 – 30 gallon pot or grow bag. If you don’t speak “gallons”, just look for pots or grow bags that are about 20 – 24″ across the top. This will ensure you don’t have to water every 30 seconds, and hold enough soil to provide enough nutrients to the VERY large luffa.
Don’t forget they can easily get to be 30′ long under the right conditions so if you want to grow them on a balcony make sure there’s somewhere for them to grow. It wouldn’t be out of the question for them to grow up your balcony and onto your upstairs neighbour’s balcony.
You’ll be super pissed if they get all your luffa sponges.
Part of the reason I had such good success with my germination rate is that I harvested the seeds myself, from my own Luffa, only a few months ago. That’s half the battle, having fresh seeds. But if you don’t have that luxury you can buy luffa seeds from reputable growers. I got my original seeds from William Dam Seeds.
And don’t be discouraged if you only get small luffas. They’re just as useful and infinitely more cute than huge ones. I used my small luffas in gift baskets that I gave everyone at Thanksgiving.
So there. Now I’ve told you how to do it. My job is done.
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