A Whole Branch of Wartleaf Ceanothus, Chopped into Cuttings

Wart leaf ceanothus with blossom

Wartleaf ceanothus,  Ceanothus papillosus, grows here natively. Unlike the tree form of ceanothus that occurs here (Ceanothus thyrsiflorus) it's a shrubby form, somewhat sprawling and angular -and, yes, it has warty leaves that are not too appealing, in a garden way, to be quite honest. But overall, and when it's blooming, it's quite lovely, and quite drought tolerant.

Growing wild along the neighbor fence.
In fact it grows in very poor soil on our chaparral slope and down by the road. It seems OK with sun or part shade. It pops up in the most unpromising spots. But I have so far failed to propagate this shrub. The tree form, Ceanothus thyrsiflorus, yes, from seeds. But this one - I tried cuttings in 2009, no success. I tried seeds. Nada. On Las Pilitas Nursery web site, I read:
This species is difficult in the nursery and in gardens. Not for a beginner. Some years, not for experts. 
 Well, at least I don't feel so all alone.

Anyway I took a notion last weekend, and cut a fairly large branch off one specimen that was growing out into the road. Like a good hunter-gatherer who uses up every bit of an animal, I made cuttings out of every morsel of that branch. I figure I'll try it all. Hardwood cuttings from the base, semi-ripe (which I take to mean not quite hard) cuttings from the thinner, somewhat softer woody bits, and tip cuttings.

I got most of my info about hardwood cuttings from this great book: The American Horticultural Society Plant Propagation. Editor in chief is the wonderfully-named, Alan Toogood. It says you can take hardwood cuttings from late autumn to mid winter. But on the Native Plant Network propagation protocol page for ceanothus in general, it says to take propagate using semi-hard cuttings in May. So if this lot doesn't work, well, that's the thing with propagation - there's generally always another chance. I'll also try from seed again next season. Try, try, try, again!

So, according to the above book, to prepare hardwood cuttings of evergreens, you cut them into sections 8 to 10 inches long. Just below a node at the bottom, just above a node at the top. Strip the leaves off the lower half, and stick them in a large pot (if you're doing just a few). You can also put them directly in the ground. Plant Propagation recommends soil-based rooting medium, defined as follows:

  • 2 parts soil
  • 1 part peat or peat substitute
  • 1 part sand
  • To each 8 gallons (36 litres), add 1.5 ounces (42 grams) superphosfate, and 3/4 oz (21 grams) limestone.
This book is not specifically for native plants, so I took the general idea and adapted it. What I did in fact was use about equal parts perlite, potting soil, and native sandy soil. Then I added a bit more soil. And a bit of sand. And a few granules Osmocote. I was aiming to get a fairly well-draining and not too rich mix. Not very scientific, but quite a lot of fun.

To prepare the tip cuttings, I took three- to five-inch cuttings, cutting just below a node, stripped the bottom half of the leaves, trimmed the leaves I left on the top half so they didn't make it too top-heavy, and removed any buds. Then I popped them into a seed flat full of a mix that is mostly perlite with a bit of potting soil and vermiculite.

Also I soaked their ends in a liquid rooting hormone for a bit before putting them in. I did the same to the hardwood cuttings though it didn't say to do that. One day I'll take a class in propagation, and get much more informed about all this, but in the meantime, I'm having fun learning by doing.

Hardwood, semi-hardwood, and tip cuttings of wartleaf ceanothus. Bamboo stakes added round the edge to keep the plastic cover off them.

I put them all on the heating pad set to 85 degrees F, and draped them in plastic. Oops - I read on the Native Plant Network that they use 21 degrees C (70 degrees F)!! -- I just ran out and turned down the thermostat!

Plastic cover keeps them from drying out - but I also don't want to keep them too moist
 I haven't been keeping them totally covered because they are chaparral plants and don't lose moisture from their leaves like softer-leaved plants, and they can get mildew or fungus if they're too damp. But I do have to go to work, so they have to survive all day without spritzing. One of these days, we'll put in a misting system. I'm going to follow the Curbstone Valley folk post on how they went about it.

In the meantime, I recently bought a "mini-greenhouse," which arrived today ready to assemble. It's a set of wire shelves with a zip-up plastic cover. I think it'll be handy for keeping cuttings in so they don't dry out. I plan to assemble it and keep it in the greenhouse.

Hardwood cuttings are supposed to take 6 to 10 weeks to root, according to the book. So I'll keep you posted on their progress or lack thereof in the upcoming month or two.

Using the same general method, I made some other hardwood cuttings a few weeks ago, of California hazel, Corylus cornuta, and rose, Rosa californica, and creeping snowberry, Symphocarpos mollis, all growing natively on our property. They all seem to have rooted nicely and are starting to bud out. I'll write more about those when I take them out of the pot to check out their roots, in a few more weeks.

The nice thing about propagation is that you get to enjoy the pleasure of anticipation every day!