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Plantgasm - I love plants too much. By Derek Powazek.

The Patented Plantgasm Perlite Propagation Process

Okay, so this process is not really patented. It’s also not unique to Plantgasm. I’m a victim of my own love of alliteration. But it is a great way to turn one plant into many plants by rooting cuttings in Perlite. Here’s how I do it.

First, our parent plant.


This is a Philodendron I found in a corner of the San Francisco Botanical Garden nursery, where I’m a volunteer. My guess is that it’s Philodendron ‘Ilsemanii’ variegata. As you can see from its long, wandering stem, it’s not a young plant. It had grown so long in a little corner that it could barely support its own weight, which makes it a great candidate for cuttings.

I cut the main stem into several pieces, making sure that each one had at least three nodes (the spots where the leaves/roots come out). I potted the top cutting straight into soil. The rest of the cuttings went into Perlite in the nursery. I took the runt of the litter home where I could pay special attention to it.

I placed the cutting in a small plastic pot and filled it with Perlite. Magic stuff, Perlite. It’s made of heated volcanic glass and is extremely lightweight. It holds pockets of water and air, which is what the new roots want. It’s strong enough to hold the cutting firmly in place, but light enough to get out of the way for new roots. And it’s neutral, so you don’t have to worry about pH.

I didn’t do it in this case, but you can also treat the edges of the cutting with powdered cinnamon if rot is a worry. Cinnamon has natural antifungal properties. Plus it smells good.

Once all that was in place, I gave it a thorough watering and placed a plastic bag over the top. The idea is to create a super humid environment to inspire roots to grow.

I then placed it on a heating mat. Having a warm bottom is said to help encourage root growth. Since light is not really a factor at this stage (there are no leaves to process it), you could put it anywhere that’s warm. In the past, I’ve put rooting cuttings on top of home electronics that happen to put off a little heat. Energy recycling.

Every few days, I took off the bag and checked on the little cutting. You have to make sure there’s no rot (a sniff is usually enough to tell), run a little more water through it so it doesn’t go stagnant, and let the air cycle.

After about a month, a new growth spike appeared. I tugged on the stem and the resistance showed that there was some root action happening below, so I decided to check it out.

Viola! Here you can see the cutting has put out two new growths! This is exciting because it means it’s happy and that it’ll be a fuller plant ultimately.

You can also see that there’s one meaty root there at the bottom. At this stage, it’s safe to move the cutting to soil. I like to get the cuttings into soil before the roots get too long. It’s a shock to the plant to be repotted, and some of the new roots might not make it, so you don’t want the cutting to do too much growing in Perlite. Plus, there are no nutrients in Perlite, so the plant is living off of stored energy, and that won’t last forever.

Below you can see the final potted plant. I positioned it so that both growth tips are above the soil line. I also made sure that the root had plenty of room to grow down into the new pot. And, needless to say, be very ginger with the new root as it’s fragile. I filled the new pot halfway up with soil, gave it a thorough soak, and then placed the cutting inside. Then I carefully filled the rest with soil and gave it a little more water. I won’t water it again until it dries out a bit. Rot is still a worry.


So there you go! If the rest of the cuttings in the nursery work out as well, we’ll have five copies (clones, really) of the original plant. You can use this technique to propagate many plants. There’s no hard and fast rule about which plants you can clone this way. The best way to find out is to just give it a try.

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1 Response

D! Thank you so much for posting this: I’ve been meaning to ask you how you do this (I *so* need to do this for the ceropaegia woodii — mine is almost 6′ tall now) (!)

Posted by myla kent on 21 December 2011 @ 1am


Plantgasm is where Derek Powazek chronicles his botanical antics and misadventures. More.