This Unexpected Propagation Hack Uses a Cucumber to Multiply Your Lemon Tree—but Does It Work?

Lemon trees can be costly and finicky to grow, especially outside of warm climates. Propagating them is also tricky, but a few simple tools might make that easier—and you may have one in your refrigerator.

In a recent Instagram Reel, the creator @gardeningwithmom_ explains how to propagate a lemon tree using a cucumber, a small plastic cup, and a little bit of potting soil, all applied directly on the branch. We’ll explain how this process works and whether the cucumber plays a vital role or if it was included just for a fun twist. 

How to Propagate a Lemon Tree with a Cucumber

This popular gardening trick comes from Mr. Wong, the creator’s neighbor, who has been growing lemon trees for years. The caption simply reads: “What happens when you bury a cucumber like this? Cut it in half, stick it to a tree, fill a cup with soil... and wait. You won’t believe the results!” While this description makes the process seem exceptionally easy, the video shows 10 steps that take 40 days to complete. 

Air Layering

The process shown is known as air layering, a propagation technique that has been used for thousands of years. The benefit is that it skips the seedling and early growth stages, where a plant is especially vulnerable.

After the process, the video explains that you get a new lemon tree with the roots, leaves, and original genetics of the mother plant. In theory, this technique should work on most woody plants, like pear, fig, and apple trees.

Propagating Steps 

To try this version of air layering, you’ll first need an existing adult lemon tree, a cucumber, a plastic cup, plastic wrap, potting soil, tape, and a box cutter. Here’s how to proceed:

1. Make two cuts around the circumference of a young lemon tree branch about 2 inches apart.
2. Use a knife to remove the bark between them and lightly scrape the area, which the video says stops nutrient flow and encourages root growth.
3. Cut the ends off a cucumber, slice it lengthwise, and carve out a groove in the middle.
4. Secure the cucumber around the branch using toothpicks.
5. Cut open a plastic cup, and wrap it around the cucumber, then secure it closed with tape and fill it with firmly-packed potting soil. 
6. Water the soil thoroughly, and wrap everything with a black plastic bag to keep it moist and warm.

After 40 days, remove the bag and, barring any rot, you should see roots have filled the cup and no more cucumber (it decomposes).

Do You Really Need a Cucumber for This?

The video claims that the cucumber acts as a natural fertilizer in the propagation process, but it’s unclear if it’s actually necessary. According to one plant biologist in the comments, the cucumber isn’t needed. “Neither is the plastic cup,” they wrote, adding that the branch “should be wrapped to keep out contaminants.”

A horticultural scientist weighed in, too, mentioning that not only is the cucumber not needed, but it could be harmful.

“Air layering is a highly effective propagation method for many species, but the cucumber is unnecessary,” they wrote. “I know if I had taken an exam asking about whether to include or not include the cucumber—the answer would have been not to include the cucumber due to the many infections it could introduce.”

According to this horticultural scientist, the tree will produce new roots perfectly fine with just soil, and you could even add compost, which to them is better than a decomposing piece of plant tissue that inevitably rots over the open wound of your lemon tree.

Another hobbyist shared their experience of propagating by just planting a lemon tree stem in soil, which seems like a much simpler option. “I made two lemon trees last year from cuttings off my existing lemon trees,” they wrote. “I just cut off about a 3 to 4 foot branch end, removed lower leaves, and stuck it in a pot of Miracle-Gro soil.” Their lemon trees rooted just fine and have already grown into little trees this year. Whether you want to do all that extra in the video is up to you.