A lot of cutting propagation tips from a pro

Let it just be said that the chief propagator of a well respected nursery that supports our CNPS propagation group recently gave up his Sunday morning to train the group in the art of taking cuttings. My task is to create documentation for new volunteers. As I work on the material - I'd like to give you an abbreviated version, to share a few of the wonderful tips he shared with us. Tips. That's a pun, get it? I'm including the basics here too.

General hygiene
Keep it clean! A professional nursery knows the value of hygiene. They wipe down the stainless steel tables with dilute bleach solution between sessions, and spray rubbing alcohol on the clippers between batches of cutting material, in case of bacterial infections.

Cutting material and preparing different types of soft cuttings:

Use soft material, not woody hard material. Use judgment. If you have good, controlled conditions, soft tips are the very best for most plants.

If you use hard woody material, the cutting will just sit there. Soft cuttings - three to four weeks to rooting generally. Woody cuttings - a year. (Note that there are different techniques for woody cuttings that take a long time - not covered in this post.)

Use material that has good form - not twisty. If you only have twisty material - use it and later prune for form.

Top right clockwise: tip, second, hammer, heel cuttings

To form the bottom of the cutting, cut below a node, not too close to the node.

To form the top of a second or heel cutting: Cut above a node - leave a quarter inch max above the node.

Some plants can grow without a bottom node if cuttings are made in spring but - why bother trying?

For tip cuttings, cut out any buds or fruits. Sometimes it's a good idea to wait a  few days to do that because the stem of the buds or fruits may grow a little making it easier to cut off without damaging the cutting.

CUT the lower leaves off. Do not strip them down with your finger. Damage invites fungus.

If a plant has been stressed, if it has grown lanky and soft - tips are not so good. Also if it's hot and you don't have ideal conditions - keeping the plants a bit cooler than the outside air -- don't use tips. Use judgment.

Leave a node at the bottom and don't cut too close to the node

One node - two cuttings. Hammer cutting

Summary of Types:

-- Tips: the growing end of the stem and two or three nodes depending.
-- Seconds: the cutting(s) below the tip (or more than one cutting if a long stem). Two or three nodes.
-- Heels: Where the side stem you are using for cuttings joins the main stem, and you tear off the side stem and take a little of the main stem with the cutting.
-- Hammers: For plants with opposite leaves like salvias and garryas - you can get two cuttings by splitting a stem in two - the side shoots grow into separate cuttings. Good if you are short of material. they tend also to make bushier plants.

Very soft cuttings will not do well in hot weather - they need controlled conditions.

Toyon better propagated from seed. Also Holodiscus discolor.

Bushy plants are a challenge

You can take short cuttings, removing lower leaves.
Check for disease and infestations in the cutting material. If aphids, just dunk for three minutes in soapy water and rinse. If fungus - do not touch! You'll infect the other material. After you're done with other cuttings - bag and throw in the trash.

Cut off all flowers and fruits. Energy needs to go to roots.

You don't need to keep cuttings in water. They can stay out for up to a day - not in the sun of course.

TIP!  You can make cuttings from cuttings -- After cuttings grow, it's common to pinch the tips to encourage bushy plants -- you can use those pinched out tips to make more cuttings! Excellent material. If you have good growing conditions for them.

Rooting hormone 

Wear surgical gloves to keep the rooting hormone off your skin. Not good for you.

Just dip the end of the cutting in the hormone powder (Hormex for example).

In general: use hormone powder #3 for soft, #8 for woodier material - and certain plants that are difficult to root (you have to find this out yourself from books, on-line, expert people, etc).

Sometimes you may want to use #3 for harder cuttings. They will take twice as long to root. This can be useful to get more robust cuttings - slower but stronger. Or perhaps because the cutting material is not the strongest due to stress of some sort.

Planting cuttings in the trays

Fill the cutting trays full of media all the way to the top and pack them firm. I didn't ask what the media mix is, unfortunately.  It's generally lean for cuttings - perlite, vermiculite and peat with sometimes other ingredients.

Flats are filled to the top and firmed down. When picking up a flat keep the sides squeezed in.

You don't want to let the flat twist so that cracks open. (Especially after cuttings are placed)
At the nursery they cut open a narrow trench for each row cuttings to drop into using special blades they make at the nursery. At home you might use a pencil to make a hole and drop the cutting in. Or you could use one of those kitchen blades you can buy for scraping stuff off a pastry board.

Don't mix cuttings with different needs in one flat: Just as you don't plant different types of plants in one bed - don't mix cuttings with different requirements in one flat. Mist or no mist. Fast or slow growing - Tall or short (if that makes a difference to the time they will take or water they need) -- keep them separate.

Don't push the cuttings in--especially soft cuttings.

When planting, don't cover the first pair of leaves. How deep varies by plant. In all cases the cutting has to be stable, not wobbly in the flat. Harder wood cuttings are planted deeper.

Close the trench or hole firmly.  Cuttings need to be very firmly snug. No air pockets - roots don't grow if there are air pockets.

Water the cuttings in twice - once when you just put them in, and then again when you place them where they will grow. Water gently from all angles not just one angle. Water gently.

Water from all directions - to the left,

... to the right

You can carefully firm in any cuttings that are loose

The second watering also ensures that any extra hormone is washed off the base of the cutting. Too much hormone can cause burning.

Check the cuttings after you water. If you have small nimble fingers you can firm in any that are knocked askew.

Caring for Cuttings

In general: Not all cuttings require mist. Think about the habitat - if they are chaparral plants, generally no mist. If riparian - mist. The leaves are a clue.

No mist examples: epilobium, salvia, mimulus, artemisia, penstemon, solanum, keckiella, malacothamnus

Mist examples: Spirea, philadelphus, cornus (manzanita in summer but not winter), symphocarpos, lonicera, holodiscus (but better from seed), rosa

Also if hairy leaves - no mist. It traps moisture leading to fungus.

Botrytis - grey fungus - happens easily, with moisture and warmth.

Hormone 8: in general the mallows (Malacothamnus) and Vaccinium ovatum.

Epilobium, manzanita, ceanothus, toyon - have better success in winter, outside in the shade house. But if you do them in summer - then they need mist because of the change in temperature daily, to avoid temperature swings. You have to check on them daily and make adjustments.

It's important for the temperature to remain fairly steady - even 10 degrees Fahrenheit difference in a day can cause damage. If it gets hot - increase mist.

At the nursery they have a table where the cuttings are not automatically misted - someone visits them once or twice a day and gives them custom watering as needed to maintain the consistent conditions they need.

Many plants take three to four weeks to root.

TIP! You can leave many types of cuttings in the trays an extra three to four weeks after they have rooted. This can be useful to delay growth so they are ready for planting (or selling) when you want to do so. Some cuttings don't do well if left in too long. Dendromecon (bush poppies, Romneya (also poppy family), for example, have soft easily-broken roots.

[From another nurseryperson I learned that you can also keep them in their 2" liners for longer too - in general the rule seems to be to delay the time to planting, keep them longer in the earlier stages.]

Check the cuttings frequently. You may need to prune and pinch them. Also clean out dead leaves. At the nursery they use a special gentle blower for this to avoid damaging the plants with clumsy fingers.

Wow - so many great tips were shared. I hope you have benefited from them as much as we all did.


Town Mouse said…
Great tips! I'm not always so careful about cleaning my tools, this is good advice. (Now I just need a greenhouse)
Brent said…
Nice information!
Ed Morrow said…
Great stuff - there is no substitute for experience.

If you are going to put together a more formal version of what's presented here, I bet you could make a few bucks for the CNPS by selling copies to your blog readers. I'd dearly love to know exactly goes into that rooting media. I wonder if it varies by what's being propagated?

Again thanks for the excellent info.
Country Mouse said…
Thanks for the comments. I do plant to create a handbook based on our propagation group's collective wisdom and we would perhaps sell hard copies at plant sales and so on as a fundraiser. I'd like to make a PDF available from our CNPS chapter web site for download, and hope to have chapter 1 up before too long, if that's OK with the chapter.