How To Grow A Luffa

A sustainable dream come true, I grew a sponge!! This is a long detailed post, but I wanted to include all info to help others. I will highlight the important parts to help the reading move smoother. 

Luffas sometimes spelled as loofah are a tropical vine from the cucumber and gourd family. When pollinated it bears a fruit, then left on the vine to dry out is what the luffa sponge will come to be. They have a long growing season of over 100 days. 

I am by no means any type of expert gardener. I’m fact I tried growing luffas last year and wasn’t successful. This year is a different story. I live in zone 9a which is a warm climate and luffas like it warm. However if you live in a colder climate don’t be intimidated I have heard of others in the UK successfully growing them. It’s all about timing.  I’ll give you some tips I have learned along the way. 

Where to get seeds?  I found mine at a state park’s gift shop actually 😂. If you didn’t accidentally stumble upon some like me, then check out Cheryl’s seed shop here. Please be aware she only seeds luffa seeds from December through April usually. Cheryl is the one to follow for container gardening and luffas! I learned a lot of the below tips from her.  In addition depending on my growing season I like to give luffa seeds out for free.  You need to have a postal address within the US (sorry to my international friends!).  If you would like some contact me here and I’ll let you know if I have any left.

How to start seeds? Start your seeds early. For me I start in February indoors, here in the northern hemisphere. I have found the best technique is doing the snip method. I learned about this method from Amy over on chicksandveg on Instagram. 

This helps speed up germination as the luffa seeds have a hard outer shell. Clip a tiny bit off of the non-pinched side of the seed and place in a damp towel inside of a tubberwear or bag. Check daily until you see any sprouting action. Then immediately transfer to your soil.  I would recommended to start more seeds than you think you will need. Often some don’t germinate or survive the outdoor world. They take awhile to germinate and you want to be prepared. 

What to start the seeds in? I personally use those tall plastic soup containers (5.5 inches tall by 4.5 wide)  you get as take away from restaurants. Make sure to add a few drainage holes at the bottom. I like these because they are clear. You’ll be able to see how much you are watering and you’ll be able to see how the roots grow.  The young luffa seedlings don’t like to be overwatered – just keep the soil damp. A small syringe can help with watering. Start with a seed starting soil mix and only plant one seed per container. Then place your sprouted luffa seed with the root facing down. Cover lightly with soil.  From past experience don’t start with a small container (for example toilet paper roll or newspaper pot).  Luffas do not like to be transplanted and if you start with a small pot the roots will have nowhere to grow. 

Where to place the seeds? Place in a warm sunny spot in a window indoors. Cheryl over at my Brentwood gardens on Instagram suggests to use a foil reflector. And this is a must do tip! You want to give your little seedlings all the light possible. Cheryl is the one to follow if you want expert luffa info! She also sells all her own seeds as well. I have to give her a big shoutout because everything I learned about luffa came from her!!  Seriously go give her a follow right now!

How long to grow indoors? Grow indoors until you have 6-8 true leaves. As the plant starts to grow you’ll need to add a stake to the middle for the vine to grow on. Use a stick or a chopstick. This can typically take up to 2-3 months to get 6 true leaves.  If you happen to notice some of the flowers starting to form at this point, you should immediately pinch them off. You need the vine to focus on growing its leaves and not the flowers at this point.

Hardening off: Before you plant outside you need to give your luffa babies time to adjust to the big outside world. They need to get used to wind and climate. Start by placing them outside in a shaded area on a day that is not windy, and only for 1 hour on the first day. The second day increase your time to another hour, still in the shade. The third day you’re up to 3 hours in partial shade. The fourth day up to 4 hours in partial shade. The fifth day up to 5 hours in full sun. Do this until you reach a minimum of a week. You’ll need to check for bugs daily as you bring them inside at night. Aphids are a common pest while the luffas are young. They look like a tiny black dot usual on the underneath of the leave. If you see them carefully squish it with your finger to remove them. You’ll often see a lot of green dots on the back of the leaves too; just be aware these aren’t bugs. The leaves give off this sweet nectar through the leaves pores.

Where and what to plant them outside? Find a sunny location that will get the most sunlight. Make sure that your evening temperature are 55°F (12°C) or above. You can choose to plant directly in the ground or a large container or raised bed with a trellis works well (this is what I use). Your trellis should be very sturdy, something made from metal would be good.  I’ve seen a lot of DIY tutorials online about using cattle panels.  However I didn’t have a large vehicle to transport this.  So I made my own using a 1/2 in mesh,19 gauge hardware cloth and two rebars (3/8 in X 10 feet) bent to size. Make sure you wear gloves to bend the rebar.  It actually bends quite easy with a little pressure, I used my foot on the ground to bend it to shape. I then attached the rebar and hardware cloth with heavy duty zip ties.  Its stood up well over time and cost me under $40.

What type of soil to use? Use a high quality potting soil mix, preferably with an added compost mix. This will help give your luffas a strong base to grow strong and tall. I keep the stick in my soil that I used to train them to grow upwards. Just in case the roots are attached to the stick. The young luffa doesn’t like having its roots disturbed, so when transplanting leave the stick in.

How to train the vine? You’ll need to the luffa to grow around your trellis (especially if you planted in a container.) I use old twist ties from grocery store produce. Naturally they will want to grow upwards towards the light. If you don’t train it to grow around you will quickly run out of room with no support for your luffas. They have tendrils that will grab onto anything, so giving them a good support system will help ensure for a larger, healthy plant.  Make sure to be gentle when adding the twist ties, especially on the end of the vines.  The vine ends are very delicate and can break if you aren’t careful.  If you’re using the DIY trellis like I mentioned above – you’ll need to train the vine to make a zigzag or go up and down on the trellis to allow for growth. 

How will I know when it’s ready to produce a luffa? Some quick background on the luffa plant. Unlike tomato plants where the flower has both female and male parts the luffas have theirs separate. Which means you need a male and a female flower to bloom at the same time in order for an actual luffa fruit to be pollinated.  The female flower will look like it already has a little tiny luffa in it. Usually close to the vine. The male will normally be in clusters and it comes way off from the vine. 

I was surprised myself when I went on vacation and came home to two luffas that were pollinated by nature! It’s normal that often a male will bloom without a female (or vice a versa), be patient they will eventually both bloom together in time. If you notice you have only a few males blooming and more females on the way. You can save a male flower in a baggie for a day (maybe two) and use that later to pollinate the female when in bloom. I have done this successfully before. 

Each the male and female flower will normally bloom in the very early morning. The blooms will only last for the day. So when you see its started to wilt off, thats normal. You’ll know immediately the next day if the female was pollinated or not. You’ll be able to see the luffa start to form and slowly grow bigger. If its not pollinated it will not grow and soon become bendy and fall off the vine.

Should I fertilize the soil? You can if you like. I have had success using a fish fertilizer especially when I know I’ll be on vacation and not watering them as often as I should. This will give them extra nutrients while you are away. If you’re unsure if you should do this, test it out with just one of the luffas; and wait a week to see if there are any changes.

How often to water? This is a tricky question, depending on where you live. I live in Texas where we have triple digits summers so I often water every day. Make sure that the soil doesn’t dry out but don’t over water.  They like medium watering and if you’re over watering everyday the plant may develop root rot. I like to use a water gauge and try to keep the soil in the moist section.

How to deal with pests: Ants, you’ll see these all over the luffa’s leaves and vines. It’s normal don’t worry about it. They are attracted to this sweet nectar that the luffa vines and leaves give off. 

Where I live, I often deal with sharpshooter insects. They have piercing teeth that like to eat on the flesh of the vine. Often if left untreated they will eat right through it. If possible inspect daily for these pests and apply some safer soap to keep anymore bugs from hatching. It’s hard to control all bugs. It’s a part of the eco system and sometimes it does happen sadly.

Can I eat the luffa? You actually can! But only when it is very young and green. I personally haven’t tried this myself yet but I have heard it tastes like a zucchini.

How to know when the luffa is ready to be picked? You’ll be able to see by the color of the fruit. It will turn to be a light brown color and kind of look like a big wrinkly cucumber. If you touch it you’ll notice how light it is and you can hear (and feel) the dryness of the skin. If you leave it on the vine for too long the luffa can develop some black spots inside, which is hard to remove. So it’s best to harvest them when you see they are ready.

Peel off the skin of the luffa to see the fibrous sponge that is inside! That’s the luffa!! You’ll have alot of black seeds inside. I often take a chopstick to loosen out any seeds, they sometimes stick to the inside of the sponge. From my experience one luffa can have 150-200 seeds inside. Save those seeds for future planting!

How to clean the luffa? After taking off all the seeds place the luffa in some hot water. The inside of the luffa will have some dried up sap and hot water will take it off and brighten the color. That’s it. Some people like to beach them but I don’t think that’s necessary. If you have some spots that don’t come off try pouring some boiling water over it and leave it to soak overnight.

What if the weather is expected to have a freeze before they are ready to be harvested? Cut them off the vine and bring them inside. They can dry out on their own inside off the vine. Be sure to hang or place them somewhere they will get a lot of air circulation. Never place them in a bag before they are dry because it end up with mold.

What do you use a luffa for? It’s great for exfoliating your skin in the shower. Exfoliation is great for simulating circulation and improving skin tone. I like to use my luffa in the shower a few times a week. Also try using it to clean for household chores, like dishes. Some people even place them inside their soaps! They are very easy to cut to whatever size you want. To sanitize them between uses you an always leave it to soak in some boiling water overnight. They can also be used for making crafts and decorations as well.