We are starting our fourth year of growing loofah and we’ve certainly learned a few things on how to grow loofah successfully (and unsuccessfully) from trial and error. Year one, we tried direct sowing in a partial shade location. The vines grew like crazy. All the way to the top of a nearby juniper tree…but it only produced a single blossom and zero fruit. Womp womp.
From that first failure, we learned that loofah is a tropical plant that needs a very long growing season. Even the long summers of zone 7b/zone 8a are apparently not long enough for direct sowing! Read on for more practical tips on growing loofah sponges.
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What is loofah?
Despite often being associated with the seaside in marketing, loofah doesn’t actually come from the ocean. It’s a vegetable. That’s right, a vegetable. Loofah (also known as luffa or sponge gourd) is in the same family (cucurbit) as squash, melons, and cucumbers. The fruit looks a bit like an overgrown zucchini, but the vine grows and sprawls similar to a pumpkin.
Most often loofah is used as a sponge in the shower or for scrubbing pots and pans in the kitchen. But when young and small, the fruit is edible and can be prepared like zucchini or other summer squash. You won’t want to eat it after it reaches about 2 inches in diameter as that’s when the fibrous interior starts forming. Oh, and the flowers are also edible!
How to grow loofah
Location, location, location
Loofah needs 100% full sun. Our first mistake when trying to grow loofah our first year was to plant it in an area that only got about 5-6 hours of sunlight. Nope! That vine grew and grew but not a single fruit formed. It needs to soak up plenty of rays all season long to produce successfully.
In this very sunny spot, you will also need a sturdy trellis. Loofah vines can grow 30+ feet long by the end of the growing season! Two years we’ve had it climb a nearby tree up to the top. It’s crazy! We’ve tried a few forms of trellis, but have found that along a fence works great with a little training it can grow along the whole fence line rather than take over the entire garden.
Patience
For how voracious the vine grows later in the summer, the first 2 months it will seem like it is taking FOREVER to grow or begin climbing. Unlike its cousin the cucumber, do not expect to see sprouts from loofah for closer to 2 weeks. The first year we planted them, we replanted at day 10 thinking we had failed germination. It will also feel like it takes a long time for them to begin climbing your trellis. Enjoy the honeymoon period while you have it. Later in the season you’ll be nearly watching it grow before your eyes!
Sultry Weather
Loofah originates in the tropics, so the plant needs it nice and toasty to grow well and they need a long warm growing season on top of that. Even in our zone 7b/8a climate, we have to start seed indoors and transplant later to ensure the temperature is fair enough for long enough. (Check out our favorite seed starting supplies here)
Loofah is also very frost sensitive. Not only will it kill off your plant, it will ruin your gourds if they are not picked ahead of time. Keep a close eye on the weather at the end of the growing season and make sure to harvest your loofah before the first freeze. (Click here to check your frost dates by zip code)
I’ve also read that 1-2 months before your first frost date, begin pinching off blooms to redirect the plant’s energy into the existing fruit. We haven’t tried this yet, but will give it a try this year to see if it helps the gourds develop and ripen sooner. But do watch out for ants! They love to pollinate loofah flowers and will bite you if you aren’t careful.
Transplanting and Spacing
Like most cucurbits, loofah are not huge fans of being transplanted…but with needing such a long growing season it is often a necessity if you don’t live in Florida or along the equator. To prevent transplant shock, be sure to harden off the plants and then very carefully remove the baby loofah plants from their pots and try not to disturb their roots. When planting, we like to allow about 3 feet of space between plants in a row as it is quite the vigorous grower.
When to harvest
Harvesting loofah is a balancing act. If at all possible, you want to allow the loofah to turn yellow and begin drying on the vine before the frost arrives. If you harvest before this point is a matter of your climate.
If you live in a very humid and/or rainy climate, you may need to harvest your loofah as soon as the skin turns yellow and feels loose enough to peel off the sponge inside. If you leave them too long in humidity or allow them to get wet during the drying process, the sponges will mold inside or develop black rot spots on the outside. Brown is good. Black is not.
If you live in a climate that has an earlier frost, you will want to harvest your loofah the first night frost or a freeze is forecast. If they are not completely dry on the vine when harvested, you will want to peel them within a few days and hose off the sponges and allow them to air dry. Otherwise you’ll be dealing with mold or rot issues. For more detailed harvesting and seed saving tips for loofah, check out our previous blog post.
