Spring Plant Propagation Workshop with Sam Kaup

On April 26th Sam Kaup from Zephyros Farm and Wild Plum Nursery presented a workshop on plant propagation at the Coffa demonstration garden and classroom! He spoke about tips and tricks for how to create many plants from a parent plant, including techniques such as: division, suckering, layering, stooling, root cuttings, stem cuttings, semi hardwood cuttings, and hardwood cuttings. Read on to learn more about each of these techniques.

Sam has spent his life on the western slope of Colorado developing a deep love and appreciation for our native plants, ecosystems, and landscapes. His background is in natural sciences and agriculture, and he has been farming in the North Fork Valley for around 10 years.

Sam presenting at the COFFA demonstration garden about plant propagation

General Best Practices for Propagating Plants

Sanitize shears, pots, and shovels; it helps reduce the spread of disease to new and mother plants
Use sharp shears, clean cuts will help the plant
Light and well-draining sterile potting mix helps maintain correct moisture and reduce rot
High humidity and low light; reduces the transpiration of the plant until roots develop
Keep a warm root zone, but not too hot
If you are wounding the plant, make sure your tools are clean and only do this to expose the cambium
Rooting hormones can be helpful
Take cuttings in the morning when cool and full of moisture

Different propagation methods are described below from easiest to hardest. Already rooted propagations will be easier.

Division

Cutting a chunk of the low ground crown
Possible on plants with spreading crowns
Rhubarb, comfrey, yarrow, etc
Look for pieces with eyes and roots
Remove most of the above-ground surface area
Possible all year, ideal in spring or fall

Suckers

Shoots that initiate below ground, either from primary root systems or rhizomes
Not all plants do this
Plums, hawthorne, elderberry, grasses, lilac, locust, gambleoak, snowberry, sumac, raspberry
Carefully dig so as not to injure the mother plant
Expose and sever sucker below a point where it has already rooted
Possible all year. Ideal in spring and fall

Layering

Different techniques, but all try to get roots to form on an above-ground shoot that is still connected to a mother plant

Ground layering

Rooting a stem that touches the ground and gets covered by soil or debris
Natural way of layering for mint, blackberry, Jade, and low-growing spreading shrubs
How to: Bend the shoot down and wound the stem, use rooting hormone, then bury and staple it down to the ground
It may take 6 to 12 months to root well. Cut off with enough time to establish before winter

Air layering

Same concept as ground layering, but creating an artificial root zone above ground
Wound the stem, apply rooting hormone, and place moist peat around the wound, then wrap in plastic to seal in moisture. Cover the plastic with foil to keep light out and a lower temperature.
Let the roots establish before cutting off the layer
It can be helpful in low quantities with plants that don't naturally divide, sucker or layer or for plants that are difficult to root from cuttings

Stooling

Same layering concept
Coppice mother plant in spring as new shoots grow and wound stems at the base. Use a hormone and cover with peat, composted wood chips, or light soil
Remove the covering once rooted during dormancy
This is common for fruit tree rootstock. Propagation can also be used for chokecherry and Aspen

Root cuttings

Cutting of a medium-sized shoot that will root and put up shoots
Take a pencil to finger-size root that is 3-12 in long
Taken during dormancy to not injure the mother plant, and for peak root energy reserves
Expose the root near the crown and carefully and take clean cuts
Useful for blackberry, choke cherry, elderberry, sumac, locust
Often successful with plants that sucker or have rhizomes

Stem cuttings for softwood

More difficult and generally higher chance of rotting or dying
This is taking a non-rooted cutting of above-ground plant stems
Different age, woodiness, and timing depend on sthe pecies
Pencil-thick cuttings are generally best, but not always possible of fresh young growth before it starts to get Woody
There are different methods for rooting
Look for a healthy, vigorous growth from the canopy
Take a 45° cut on the bottom of the stem
Trim down to a small amount of leaf area
This is good for cannabis, goji, Russian sage, and many herbs
This is generally done in spring and summer

Semi-hardwood cuttings

Stems that are starting to stiffen (will snap like chalk)
Medium ppm rooting hormone
The techniques are the same as taking softwood cuttings
Plants for this technique are false indigo, currant, naking cherry, nine bark, and smoke bush
These cuttings are taken in mid-summer

Hardwood cuttings

Mature Woody stems
Higher ppm of hormone
Willow, cottonwood, dogwood, grape
Most common during dormancy (January or February), but can do whenever

What to do with your cuttings

The water method

Place plants in a jar of water
This is the simplest method and can be surprisingly effective, but the plants can develop a rot and weak root systems. This is best used for house plants

A humidity dome

Use moist soil made of peat, perlite, and sand
Dibble a hole and bury the stem 1 to 2 in
Use a dome or a plastic bag to make a 100% humidity environment
Mist inside the dome 1 to 2 times daily
Use bottom heat for 60 to 80° soil

A mist bed

Use well-draining soil of peat, perlite, and sand
Intermittently mist 5 seconds every 5 minutes or so
Can use a heat coil in the soil
This method maintains high humidity and cool air temperatures while maintaining airflow

Thank you to Sam Kaup for sharing all of this amazing information with our community! if you are interested in items from his Wild Plum Nursery, contact him at swkaup@gmail.com.