I just stick cuttings of pentas either in water (makes a nice indoor bouquet) or in the ground. Most will root that easily.
Anna is the penta queen and might be here sometime with more info. (Look at her pics and you'll see what I mean!)
Hester

Hi Tropicalfreak!

I do have a lot of pentas, but am in no way a "penta queen." I only use the tall pentas in my garden because I find they last longer, the butterflies and hummers seem to like them more, and although all pentas are nematode prone, the tall ones seem a bit more resistant- at least for a while. Either way, even the tall ones last only three years for me, but the dwarf only would last for one season or a year at most for me.

Therefore, because the tall ones are hard to find at nurseries, I am always attempting to make more. I usually cut a long branch (at least two nodes, but works better with three. I wait for a good rain, and then stick them in the ground to cover at least two of the nodes. I cut all the large leaves and buds/flowers off, usually the tips of new growth, and cut most of the remaining leaves half-way. Where many of mine fail is that I then forget to water them. Ideally, a good soaking every couple of days is good. Because of my neglect, only two or three out of five take. It will take almost a year to become a large plant like I love, and I keep doing that over all the warm, wet season, every place I have a spot. I love, love, love tall pentas and all creatures do also. If you ever run into the tall ones, and have the space, definitely try them! Local nurseries are the best source (not big box stores), and if they get to know you, sometimes they will order them for you.

Hester seems to have good luck with rooting them in water, so try both approaches and see what works best for you! Good luck and happy propagating.

Anna

If anyone wants cuttings of the tall red ones, I have A BUNCH from my trimming today. I've put them in water and will keep them till the trash comes this Friday. Mine are either Ruby Red or Ruby Glo. Some of my came from the USF plant sale from a guy out of Brooksville. Last year I didn't see him there and was told that the freeze did most of his plants in - but since we had a mild winter this time, hope fully he will be back. He usually only has Pentas and a few other natives, not a large display.

But I have plenty someone wants to drive to Lakeland.

I have to say, Anna, that in all my years of gardening, your August 2011 advice to plant two nodes (or even better, three nodes) has been the single piece of gardening advice from which I have benefited most. Up until I read that post, I had never read anywhere, and it had never occurred to me, to take LONGER cuttings, thereby putting more nodes in the ground and giving the cutting a better chance of rooting . Being thrifty, I always took as little plant material from the mother plant as possible (so as to leave more plant for more cuttings). But boy did I learn something from you that day. I now use that method on all my cuttings, no matter what type plant. I use it on hypoestes (polka dot plants), firespike, poinsettias, pentas, mona lavender, cat's whiskers, impatiens (in the past, before the fungus-among-us), bloodleaf, joseph's coat, hydrangeas, shrimp plant and others. Because the method is so successful, I start most cuttings directly into the ground, skipping the intermediary step of starter pots. Maybe planting two or more nodes was obvious to others, but I never even thought of it.

So Anna, I say to you, that you have had a bigger impact on my gardening than any other single piece of advice I have ever received. It was absolutely a gem and I thank you! New gardeners, take heed!

Carol in Jacksonville

Hi Carol,

Isn't it wonderful to resurrect old post and actually have them show up at the forefront for everyone to see ;-)

I need to take some penta and firespike cuttings this weekend so I'll give this a try, like you I was always taking just one node....

Tom

Tom and Leekle,

Reading Anna's post was such an Ah-Ha! moment for me that I still think of it every time I am rooting cuttings. I hope Anna sees this... I think she comes here to read every so often.

I find firespike very, very easy to root. I just make a hole in the ground with a stipple/stick, pour water into the hole, put the cutting into the hole and firm up the soil around it. I think I am at 100% survival directly in the ground when starting early in the year (now) and watering daily. That method will not work June/July/August when it gets really hot or in direct, full sun.

Never tried it horizontally but I know that if you can get plant material to root horizontally, you get more plants (one node per plant vs. using two nodes per plant when rooting a cutting vertically). Let us know how that goes!

Tom, I still struggle with pentas. From my research it appears they take 3-4 weeks to root no matter what method is used.

Aren't we having FUN?! :)

Carol

I like to put the cuttings in clear plastic drink cups so I can see the roots. Some stuff I root, like hibiscus, will start to bud out first and it drives me crazy to think it's time to pot up, only to find there's no roots yet when I lift them.

And even though I know that, it seems like if there are little leaves forming, there should be a bunch of nice white roots, too. So being able to see them through the plastic keeps my curiosty in check.

Yes, Carol -it sure is FUN! (Wasn't that a line from "Moonlighting"?)

Susie

HOLY COW. I mean, really, HOLY COW! I finally rooted pentas!!!!! It took 15 days in water in an east-facing window.

I bought three new tall, hot pink pentas plants this year. Being as that I just haven't had that much luck with rooting pentas, I was somewhat reluctant to cut much to fool with. But I remembered what Hester wrote above about rooting in water and thought, "I'll give it a try."

I took four cuttings and put two each in small clear jars of water. I put them in an east-facing window. I only partially open the blinds each morning until the sun has passed overhead so they got no direct sun. I never changed the water because I really wasn't paying much attention.

I started them on April 9 and on April 24, 15 days later, I took a closer look and by darn, if there weren't white roots on those babies! Unbelievable - I have never had good luck with these things. The three cuttings with only one node in water all rooted. I had one cutting with two nodes below the water line and it did not root. The lower node appeared to be rotting. I cut it off just below the higher node and put it in fresh water. I potted up the other three in tiny starter pots. They are in full shade while they get a little stronger.

Of course, I immediately went and made more cuttings. I used the method linked below to prepare the cutting and nodes. Now I'm acting all like I have this down. I hope I don't disappoint myself, LOL. Here's photos of the first batch.

Thanks, Hester, for more of your good tips! That was way easier than prepping them in tiny pots and watching them cycle through wilt/rot/wilt/rot.

Carol in Jacksonville

Here is a link that might be useful: Rose Propagation Forum - Is this how you scrape the cuttings for rooting?

"Never tried it horizontally but I know that if you can get plant material to root horizontally, you get more plants (one node per plant vs. using two nodes per plant when rooting a cutting vertically). Let us know how that goes!

Well, here it is. Apparently 'planting' firespike stems horizontally in a pot will indeed result in plants coming up at each node.

In fact, not that I was trying, it just kind of happened, you can even root the leaves.

Oh wow. At my very first plant sale last July, I purchased a 3' red Firespike from Vince (Island Stylin) and he gave me 2 small rooted cuttings to go with it.

Since then, I'd propagated a few from cuttings and separated a few plants to the point I've probably got 10 or 15 3' firespikes growing currently. They do root easily, but I hadn't even considered horizontal propagation, let alone propagating from leaves. That's something I'll definitely have to try soon.

Gosh I love learning something new and useful each day.

Are they leaf stubs, or are they branch stubs?

Not sure, since it's been several years. Highest success rate in March and early April, the start of growing season, when you can root just about anything, including a pencil. Lowest success rate during Oct - Jan when everything is/is going dormant.