Simple, Bulletproof Plant Propagation

Winter garden blues got you down? This is the best time to propagate some new plants – especially California and Mediterranean natives

I’ll be honest. It’s been winter for all of four weeks and I’m already getting antsy to get back in the yard and get to work on my grand designs for 2023.

Alas, here in California, we’ve been swimming in an atmospheric river and received as much rain in a month as we normally get in six. The Acre is a muddy mess (bright spot: the ducks are happy).

Plus, we’ve still got at least six (probably eight) more weeks of messy winter weather to go. Given my luck, that would pretty much guarantee anything I got started outdoors would be destroyed by the time spring shows up.

So here I sit, staring out the window, getting antsier. But I have a solution.

Propagate in Winter for Spring Success

Fortunately, while it may not be the best time to be rooting around in the garden, it is a great time to propagate new plants—especially woody perennial shrubs—from cuttings.

Here in San Diego, and throughout most of California and the desert southwest, fragrant and colorful natives like sages (salvias), sagebrushes (artemisias), and gooseberries (ribes), are just starting their growing season, which makes their cuttings very easy to root. The same is true for mediterranean plants like rosemary, lavender, rock rose, Jerusalem sage, and many others.

The reason winter is a great time to propagate (or “clone” as some call it) these plants is they all come from places where winter is the rainy season, which gives the plants the chance to expand their roots, shoots, and leaves before putting their energy into flowering and seeding in the warm, dry weather of spring and summer.

In my own experience, I’ve found the success rate of even hard-to-root cuttings goes from about 50% in spring to nearly 80% in winter. For more cutting propagation-friendly plants like lavenders and sages, it’s more like 99% (in fact, I’m actually surprised when some of these cuttings don’t make it).

Bulletproof Propagation the Cheap and Easy Way

You can spend a fair amount of money on materials and equipment for propagating from cuttings, or you can do what I do, and spend next to nothing (which, in my opinion, makes it all the more enjoyable). Here’s what you’ll need:

Supplies

• One gallon plastic milk / water jug(s) – one jug will hold 5 or 6 cuttings
• Rooting medium – use coconut/wood bark, peat, vermiculite, or sand (cactus, not paver sand)
• Tools – scissors/clippers and a small, round stick
• Plant cuttings – cuttings from last year’s wood that’s got green growth

Step 1 – Cut your milk jug in half

If you’ve ever made milk jug greenhouses, you know this one. Use a pair of scissors or a sharp knife to cut your milk jug(s) in half. I generally make the bottom about 2-1/2 inches deep, which is deep enough for good soil contact for the rooting cuttings, but not so deep you have trouble teasing the roots out to transplant.

I also make a slit in each of the corners of the bottom, which makes it easier to squeeze the edges and slip the top of the jug on without disturbing the cuttings

Step 2 – Add rooting medium to the bottom of the jug

After testing all sorts of media and media combinations, my favorite rooting medium is compressed coconut bark and wood shavings. It’s cheap, easy to work with and does a great job of both holding and draining water. Peat, vermiculite, sand, or any other sterile medium that won’t compress when wet works well too.

Add the medium to your jug bottom, add enough water to make it damp, and pack it down a little so it holds its shape when you make the holes for your cuttings.

Step 3 – Make some holes

Using a stick (or what the pros call a “dibble”) make 5 or 6 holes in your rooting medium.

The holes shouldn’t go all the way to the bottom, but they should be far enough apart that the cuttings won’t touch each other when they’re inserted into the medium.

Step 4 – Prep your cuttings

If there’s one “trick” to getting cuttings to root, it’s choosing the right cuttings to begin with. You want to select a stem / branch from last year’s growth that’s actively growing and leafing out.

The easiest way to identify a good candidate for cuttings is to look for stems that are brown and woody with lots of leaf buds going toward the center of the plant, and green and leggy as it gets further from the plant.

Once you’ve got your plant stems, it’s time to turn them into cuttings.

First, cut off and discard the new green growth on the branch. Then cut the remaining brown wood into roughly 2-inch segments. Cut the branch just below a leaf node and leave four or five leaf nodes above it. If you select a long branch, you can make several cuttings from it.

Once you’ve cut the segments, strip off all but the top leaves. (If the leaves are large, you can cut them in half to reduce water loss through the leaves. Otherwise, just leave them as is.)

Each of the stripped off leaf nodes on the cutting’s stem are where the plant will form new roots. If you want to encourage faster rooting, you can dip the stem in rooting powder, but I find with most cuttings, it’s not necessary.

Once your cuttings are prepped, place them in the holes you created in your rooting medium. They should be deep enough that several leaf nodes are in the soil, but not so deep that the bottom of the cutting touches the container or the top leaves touch the medium.

Press the soil in around the cuttings to ensure the stems have good contact. Also, make sure the cuttings aren’t touching each other. Like siblings in the back seat of the car, bad things can happen.

Step 5 – Cover and put them away

Place the top of the milk jug back on the container and set it somewhere with a consistent temperature out of direct sunlight.

The location doesn’t really matter. It can be indoors or out, and doesn’t need to be a warm or cold temperature, just an even one that won’t shock the cuttings with sudden temperature changes. Keeping them out of direct sunlight will let them focus on putting down roots rather than trying to grow leaves and flower.

I keep mine under a bench in my cold greenhouse, but I’ve also kept them in the garage and house and had similar successful results, so you shouldn’t worry about “where” too much.

Step 6 – Watch and wait

At this point, there isn’t much to do other than let nature take its course. Check on the soil every week or so to make sure it stays moist (not wet), and remove any cuttings that drop their top leaves or get moldy.

After four to six weeks you should see the first signs of new leaf buds growing at the top of the cutting. Wait until these leaves get larger and you see a stem and second set of leaf buds growing from the leaf junction.

Step 7 – Transplant into pots

Once you see the plants are actively growing on their own, tease the plants out of the soil with a spoon, hori knife, etc., taking care not to damage the roots.

Transplant into a larger pot (I use 4 inch plastic pots, but peat, clay and other pots are fine too), and move it to a brighter spot (not direct sun just yet). Let the plant(s) continue to grow for several more weeks.

Step 8 – Plant it!

Once the plant has four or five sets of new leaves and looks healthy, it’s ready to transplant into the ground or a container. Keep it moist for the first week or so to ensure it gets established, and it should be fine from there on.

If you’re growing salvias, lavenders, or other late-spring / early summer blooming plants, you’ll probably see flowers in the first year. If they’re plants that take longer to mature, you may not see any flowers in the first year, but you will in the next.

Here are a couple of photos of some salvias I grew from cuttings over last winter. By mid-spring they were a foot tall and blooming like they’d always been here.

Black Sage

I propagated (some would say “proplifted”) this Black Sage (Salvia mellifera) from a plant I saw growing on the hillside near the old San Luis Rey bridge just down the street from here.

What catches my eye is that it’s a lot more “purple” than other black sages, which trend toward the blue/lavender hue.

Cleveland Sage

This Cleveland sage (Salvia Clevelandii) was propagated from a very large, old one on our western slope above the vegetable garden. The parent plant finally died out last fall, but its clones live on in several locations around the homestead.

Try it yourself

If you’ve never tried to propagate your own plants, or you’ve tried but haven’t been very successful, you definitely should try this method out. I think you’ll find it’s cheaper, easier and more rewarding than going to the store add buying them.

I propagated a total of 24 sage plants last year. The cuttings were free, the milk jugs recycled, and the soil brick came from one of my wife’s many bargain-hunting missions to the dollar store. Total cost for each – 8¢!

A pretty good bargain compared to the $12 – $20 I would have spent at the nursery for the same thing!