Catalpa is a large deciduous tree with a wide-spreading habit. It can grow to 50 feet (15m) tall and wide. Catalpa bear mid-green leaves that are ovate and heart-shaped at the base. White flowers are borne in upright panicles in summer. Slender bean-like pods follow the flowers.
Catalpa are well adapted to extremes of heat and cold, and to all soils. The wide-spreading habit and flowers are best seen when Catalpa is grown as a specimen tree.
Catalpa should be shaped when young. Establish a dominant shoot and then shorten side branches as the tree grows. When branching gets to the desired height, remove lower branches.
Two other species are sometimes confused with Catalpa. Desert catalpa is Chilopsis linearis. Paulownia tomentosa, empress tree, looks much like Catalpa, but it flowers in winter and Catalpa does not.
Catalpa is a genus of 11 species of deciduous trees from East Asia and North America. Catalpa trees are usually found on riverbanks and in woodlands.
With their large, heart-shaped leaves and showy spring flowers, catalpa trees make a stunning addition to any landscape. If you want more of these beautiful trees but don’t want to wait for seedlings to grow, propagating catalpa from cuttings is a fast and easy option.
In this step-by-step guide, you’ll learn how to correctly take and root catalpa cuttings to grow new trees with exact genetic copies of the parent plant.
When to Take Catalpa Cuttings
The best time to take catalpa cuttings for propagation is during the growing season usually late spring to mid summer. This gives the cuttings time to form roots before cold weather arrives.
Specifically, aim to take softwood or semi-hardwood cuttings from catalpa in
- Late May to early June
- July
- Early August at the latest
Take cuttings earlier rather than later, as rooting success declines in late summer.
Selecting Healthy Catalpa Growth for Cuttings
Examine your catalpa tree and select shoots to use for cuttings. Look for:
- Non-flowering shoots from the current year’s growth
- Stems that are semi-hard (semi-mature) or soft and green
- Branches growing from the lower part of the trunk
The soft tips of new shoots generally root the best. Avoid using older, woody growth from lower branches. Also skip flowering stems.
How to Take Catalpa Cuttings
Once you’ve identified suitable catalpa shoots for cuttings, follow these steps:
Gather Supplies
- Sharp, clean pruners or garden scissors
- Spray bottle of water
- Rooting hormone powder (optional)
- Potting mix
- Cutting pots or trays
Cut Each Stem
- Use pruners to cut stems to 4-6 inch lengths
- Make a straight cut just below a leaf node
- Remove all but the top two leaves
Dip in Rooting Hormone
- Dip the bare end in rooting powder to encourage root growth
Stick in Soilless Mix
- Stick cuttings 2-3 inches deep in pots filled with a light, sterile soilless mix
- Gently firm mix around each cutting
- Water lightly
Provide Warmth and Humidity
- Place pots in a warm spot (70-80°F) with high humidity, such as a greenhouse or under a cloche
This protects the tender cuttings while they form roots. Avoid direct hot sun.
Caring for Catalpa Cuttings
With proper care, catalpa cuttings will form roots in 4-8 weeks. To help them along:
- Keep potting mix moist but not saturated
- Maintain warm temperatures and high humidity
- Give them bright, indirect light
Monitor cuttings for new growth. Leaves may drop off at first but should be replaced by fresh leaves once roots establish.
Transplanting Rooted Catalpa Cuttings
In late summer, test cuttings by giving a gentle tug. If they resist pulling up, they have rooted. Harden off the young plants, then transplant into pots or a sheltered nursery area for the winter.
The following spring, the rooted catalpa trees will be ready to move to their permanent landscape positions. Space them appropriately, as catalpas can grow quite large at maturity.
Tips for Growing Healthy Catalpa Trees
Here are some additional tips for successfully raising your catalpa cuttings:
- Take lots of cuttings, as success rate varies.
- Start cuttings in sterile mix to prevent rot diseases.
- Keep leaves dry when watering to discourage fungus.
- Pinch off flowers the first year to promote vigorous growth.
- Protect young trees from winter damage the first few years.
In just a single season, you can propagate new catalpa trees from cuttings. Then enjoy watching your new plants grow into beautiful, flowering catalpa specimens.
Frequently Asked Questions About Catalpa Cuttings
Taking cuttings is a simple way to get free catalpa trees, but beginners often have questions. Here are some common queries:
What is the best rooting hormone for catalpa cuttings?
Most rooting powders work fine. Use a powder containing auxin plant hormones like IBA or NAA. Or try a natural willow water rooting solution.
Should I use bottom heat for rooting catalpa cuttings?
Yes, bottom heat of 70-80°F accelerates rooting. You can use a heat mat under pots or place them above a radiator. Just keep cuttings from direct contact with heat sources.
How do I overwinter rooted catalpa cuttings?
In late summer, harden off young plants. Repot into larger containers and grow on in a sheltered cold frame or unheated greenhouse over winter. Transplant the following spring after the last frost.
Can I grow catalpa cuttings in water instead of soil?
It’s best to root catalpa cuttings in a sterile potting mix rather than water. Soilless mixes provide support and prevent issues like stem rot that can occur in plain water.
Should I mist my catalpa cuttings?
Yes, misting provides needed humidity while cuttings are forming roots. Avoid wetting the leaves to prevent disease.
How to care for Catalpa
- Prune Catalpa in winter.
- Catalpa trees need to be shaped when they are young and rarely grow a strong main stem.
- Shorten side branches as tree grows. When branching begins at desired height, remove lower branches.
When to plant Catalpa
- In the fall, plant Catalpa seeds in a seedbed or in pots in an open frame.
Catalpa blooms in the summer
