How to Propagate Cypress and Thuja: Best Tricks for Successful Growth
Growing new evergreen plants from cuttings can be a rewarding way to expand a garden, replace gaps in a hedge, or reproduce a favorite variety. Cypress and thuja are good candidates for this project, but they need more patience than many soft-stemmed houseplants.
The most practical approach for many garden varieties is to take healthy stem cuttings, place them in an airy rooting mix, and maintain humidity without waterlogging the roots. Success depends on the species, the maturity of the cutting, and the growing conditions.
Forget promises of instant roots. With conifers, careful preparation and steady aftercare matter much more than a homemade “rooting trick.”
Know Which Cypress or Thuja You Are Growing
“Cypress” covers several different plants, including true cypresses, false cypresses, and Leyland cypress. They do not all respond identically to propagation.
Thuja, commonly called arborvitae, is another group of evergreen conifers often grown for screens, hedges, and specimen plants.
For example, RHS guidance recommends semi-hardwood cuttings for Thuja occidentalis ‘Smaragd’, commonly sold as Emerald Green arborvitae. North Carolina Extension also identifies late summer as a suitable cutting period for false cypresses in the genus Chamaecyparis. white cedar 'Smaragd'
Before starting, check the plant label or identify the species and cultivar. This guide describes a general home method for evergreen garden cypresses and thuja; it is not a universal protocol for every tree called cypress.
When Is the Best Time to Take Cuttings?
For many varieties, late summer to early autumn is a useful starting point. The current season’s shoots have begun to firm up while retaining healthy foliage.
These are called semi-ripe or semi-hardwood cuttings.
Hardwood cuttings are another option for suitable conifers from mid-autumn through late winter. The RHS lists both seasonal approaches for conifer propagation. rhs.org.uk
Use the condition of the shoot rather than a date alone:
- Very soft growth loses moisture easily.
- Semi-ripe growth has a firmer base and a more flexible tip.
- Mature hardwood is firmer throughout and may root slowly.
If you are starting in November in the Northern Hemisphere, suitable hardwood material and a protected rooting environment may be more appropriate than searching for soft summer shoots.
Gather Your Supplies Before Cutting
Prepare everything first so freshly collected shoots do not sit around drying out.
You will need:
- Clean, sharp pruners.
- Small pots or a propagation tray with drainage holes.
- Fresh rooting medium.
- A clear propagator lid or plastic bag supported above the foliage.
- Plant labels and a pencil.
- A dibber, pencil, or small stick for making planting holes.
- Rooting hormone labeled for suitable woody cuttings, if used.
- Gardening gloves.
Wear gloves when handling thuja. The RHS identifies its foliage as a potential skin allergen and harmful if eaten. white cedar 'Smaragd'
1. Select Healthy Shoots From a Healthy Parent Plant
Choose a plant with good foliage and no obvious pest damage, dieback, or disease.
Take manageable pieces of recent growth rather than large, old branches. Younger stock plants often provide material that roots more readily than very mature specimens.
Collect shoots early in the day, when they are less likely to be wilted. Keep them cool and protected from moisture loss while you prepare the pots.
NC State Extension emphasizes that parent-plant condition, cutting maturity, and water stress all influence rooting success. NC State Extension Publications
A useful habit is to label each batch immediately with the plant name and collection date. If you try more than one variety, keep them separate so you can compare the results.
2. Prepare Cuttings Without Stripping Away All the Foliage
For a small home batch, cuttings around 4–6 inches long, or 10–15 cm, are a practical starting size. Adjust to the plant’s growth rather than forcing every shoot to match exactly.
Trim the base cleanly. Carefully remove the lower foliage from the section that will enter the rooting mix, leaving healthy green growth above.
Avoid burying leafy sprays. Buried foliage can decay and create problems around the cutting base.
A heel cutting is another option: a small side shoot is detached with a short piece of older stem tissue attached. The heel should be small and tidy, not a long ragged strip. RHS Advice
Whichever method you choose, handle the stem gently and keep the remaining foliage intact.
3. Use a Rooting Mix That Holds Moisture and Air
Dense garden soil is a poor choice for a small propagation pot. The cutting needs moisture, but its developing roots also need air.
Choose a fresh, low-fertility propagation medium with good drainage. Suitable ingredients include perlite, horticultural sand, and a moisture-retaining component.
NC State Extension describes several workable rooting mixtures and stresses the balance between drainage, aeration, and moisture retention. NC State Extension Publications
For a straightforward option, use a commercial cutting mix prepared according to its instructions.
Moisten the medium before inserting the cuttings. It should feel evenly damp, with excess water able to drain freely.
4. Apply Rooting Hormone Carefully
A rooting hormone can be useful for semi-hardwood and hardwood cuttings, but it cannot compensate for dried-out shoots or soggy compost.
Choose a product labeled for the type of material you are propagating and follow its directions.
Pour a small quantity into a separate container rather than dipping cuttings directly into the original supply. Apply it only as directed, and remove excess powder if using that formulation.
Make a planting hole before inserting the cutting so the medium does not scrape off the treatment. University of California guidance recommends this approach when placing prepared cuttings into the rooting medium. ucanr.edu
Do not assume that a stronger concentration or a thicker coating will produce better results.
5. Insert the Cuttings and Keep Them Upright
Place the prepared base into the planting hole, ensuring that the bare portion is below the surface and the remaining foliage stays above it.
Firm the mix gently around the stem. The cutting should stand securely without being compressed into a dense plug.
Space cuttings so their foliage is not tightly packed together. Small individual pots can make it easier to remove a failed cutting without disturbing the others.
Add the label before moving the tray to its rooting position.
6. Provide Humidity Without Creating a Wet, Stagnant Enclosure
An unrooted cutting loses water through its foliage but cannot yet replace that water through a functioning root system.
A clear propagator cover or supported plastic bag helps maintain humidity around it. Clemson Extension identifies humid air and a moist—but not wet—medium as central to successful cutting propagation. Home & Garden Information Center
Keep the enclosure in bright, indirect light, away from harsh direct sunshine. A covered tray can overheat quickly.
Check it regularly:
- Ventilate when moisture is excessive.
- Water according to the condition of the medium.
- Remove decaying material promptly.
- Prevent the foliage from pressing against wet plastic.
The aim is a stable environment, not permanently soaked leaves and compost.
7. Be Patient and Avoid Disturbing the Bases
Cypress and thuja cuttings may need several months to form useful roots, particularly when started in colder conditions.
As one example of the variation involved, published nursery work on Leyland cypress advises allowing up to five months for rooting under its described method. That is an example, not a universal deadline. ipps.org
Green foliage does not prove that roots have formed. A cutting can remain green for some time while using stored resources.
Avoid repeatedly pulling cuttings out to inspect them. Look instead for roots visible through drainage holes or the sides of a suitable propagation container.
New shoot growth is encouraging, but confirm root development before potting on.
When Should You Pot Up Rooted Cuttings?
Wait until each cutting has a small, established root system capable of holding some of the rooting medium together.
Move it into a modest-sized pot with suitable container compost. Handle the root ball gently and keep the stem at approximately its previous planting depth.
Gradually reduce humidity and introduce the young plant to more exposed conditions. RHS guidance recommends a period of hardening off for cuttings raised under protection. RHS Advice
Do not move a newly rooted cutting straight from a humid enclosure into strong sun, drying wind, or freezing weather.
Grow it on until it is sturdy enough for planting during a suitable local season.
Common Mistakes That Reduce Success
Using unhealthy material: Cuttings taken from declining branches begin at a disadvantage.
Letting shoots dry out before planting: Prepare the pots first and work promptly.
Burying foliage: Keep green sprays above the rooting medium.
Keeping the medium saturated: Humidity around the foliage does not require waterlogged compost.
Placing a covered tray in direct sun: Heat can build up rapidly.
Expecting every cutting to succeed: Take a small batch rather than relying on one stem.
Potting on too early: A green cutting without a developed root system is not ready for the garden.
Frequently Asked Questions
Can You Propagate Thuja From Cuttings?
Yes. Many thuja varieties can be propagated from stem cuttings. Semi-hardwood material is a recommended approach for commonly grown selections such as Emerald Green arborvitae.
Can Cypress and Thuja Be Rooted in Water?
For a dependable home method, use a suitable propagation medium rather than a glass of water. The methods described by the horticultural sources here use an airy rooting medium and controlled humidity.
Can You Take Cuttings in November?
For suitable conifers, November can fall within the hardwood-cutting season in the Northern Hemisphere. Provide protection and expect slower progress than with fast-rooting summer plants.
How Long Do the Cuttings Take to Root?
Timing varies by species, cultivar, cutting maturity, and growing environment. Plan for weeks to months, with several months entirely possible.
Will Cuttings Grow Like the Parent Plant?
Cuttings reproduce the parent plant genetically, making them useful for maintaining cultivar characteristics. Seed-grown plants may differ, particularly when the parent is a named cultivar. rhs.org.uk
Do You Need a Greenhouse?
Not necessarily. A small covered propagation setup can work, provided you can maintain appropriate light, moisture, ventilation, and temperature. Protection becomes especially important during cold weather.
Disclaimer
Propagation requirements vary among cypress species and thuja cultivars. Use this guide as a general starting point, follow rooting-product labels, and consult local horticultural guidance for your specific plant and climate.
