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.
Growing a catalpa tree from seed is a rewarding project that will provide you with beautiful flowers large heart-shaped leaves and graceful shade once the tree reaches maturity. With proper care and patience, you can grow a catalpa tree from seed in your own backyard.
Overview of Growing Catalpa Trees
Catalpa trees are fast-growing, deciduous trees that grow 40-60 feet tall and 20-40 feet wide. They are known for their large, heart-shaped leaves, white flowers borne in panicles, and their long seed pods. There are a few different catalpa species, including the southern catalpa, northern catalpa, and Chinese catalpa
Catalpas are adaptable trees that tolerate a wide range of soil types from acidic to alkaline and can handle both wet and dry conditions. They prefer full sun but also grow in partial shade. Catalpas are remarkably tough trees that can withstand flooding, drought, severe winters, hot summers, and even air pollution.
When to Plant Catalpa Seeds
Catalpa seeds ripen and fall from the tree in autumn. You can collect them as the seed pods begin to split open and sow them immediately, or store them in a cool, dry place over winter for spring planting. Some seeds may need cold stratification in the refrigerator for a few weeks before planting.
The best time to sow catalpa seeds is in late winter or early spring. You can start the seeds indoors or outdoors once the threat of frost has passed. Catalpas have a long taproot and grow fast, so start them in deep pots or directly in the ground.
How to Collect and Store Catalpa Seeds
In autumn when the seed pods turn brown and start to split open, you can collect the seeds. Simply pick the pods off the tree and pull out the flat, winged catalpa seeds.
For spring planting, store the dry seeds in envelopes or paper bags in a cool, dry spot over the winter. In early spring, place them in the refrigerator for 2-3 weeks of cold stratification before planting.
How to Germinate and Grow Catalpa Seeds
Catalpa seeds germinate readily without any pre-treatment. Simply sow them 1⁄4-1⁄2 inch deep in pots or directly outdoors. Keep the soil consistently moist but not soggy.
Use a seed starting mix or loose, well-draining potting soil in containers. Outdoors, choose a site with full sun and fertile, moist soil. Partially shade the seedlings if temperatures rise above 80°F.
The seeds should sprout within 2-4 weeks. Thin seedlings to the strongest 2 per pot. Transplant the young trees into larger containers as they outgrow each pot size. Harden them off for a week or two before planting them outside.
Transplanting Catalpa Seedlings Outdoors
Catalpas grow a thick taproot, so give them plenty of root room in a large pot or by sowing them directly in the ground. Transplant them outdoors after all danger of frost, when they are 12-18 inches tall.
Choose a site with full sun to partial shade and fertile, well-draining soil. Plant them 15-20 feet apart. Water the seedlings thoroughly after transplanting and provide regular water until established.
Caring for Young Catalpa Trees
For the first year or two, give young catalpa trees occasional deep waterings during dry spells for the first couple of years. Apply a general purpose, balanced fertilizer in early spring.
Mulch around the tree to conserve moisture and reduce weeds. Prune back any crossing, damaged, or diseased branches during the first winter. Once established, catalpa trees are very low maintenance.
Common Problems With Catalpas
- Leaf spot fungus
- Powdery mildew
- Catalpa sphinx moth larvae defoliation
- Messy fallen flowers and seed pods
Prune out affected branches, improve air circulation, and rake up fallen debris around trees to prevent issues. Choose disease-resistant varieties when available.
Troubleshooting Germination Problems
Seeds fail to sprout: Old or unripe seeds, planted too deep, soil too wet or too dry, or temperatures too low. Sow fresh seeds at the proper depth in moist soil at 70°F.
Seedlings die: Damping off disease from overwatering, underfeeding, or inadequate light. Improve drainage, feed with dilute fertilizer, and provide ample light.
Poor growth: Insufficient light or root competition. Thin seedlings and transplant to larger pots or ground. Move to area with more sun.
With proper care, you can grow a beautiful catalpa tree from seed that will provide lovely flowers, graceful form, and cooling shade for years to come. Be patient and allow it time to establish itself, and your catalpa will thrive.
How to water and feed Catalpa
- Give Catalpa regular to moderate water.
- Feed Bauhinia with an all-purpose organic fertilizer in spring.
Get to know Catalpa
- Plant type: Deciduous trees
- Growing zones and range:
- Hardiness: Cold-hardy
- Height and width: To 50 feet (15m) tall and wide
- Growth rate: Medium growth
- Form and habit: Wide-spreading
- Foliage: Large leaves are opposite or in whorls of 3 are without teeth, usually unlobed or shallowly lobed
- Flowers: Large, bell-shaped, 2-lipped flowers, borne in upright, terminal panicles or racemes
- Fruits: Pendent, bean-like, narrowly cylindrical seed pods
- Bloom time: Late spring and summer
- Uses: Large shrub border, specimen tree
- Garden companions:
- Common name: Catalpa
- Botanical name: Catalpa
- Family name: Bignoniaceae
- Origin: East Asia and North America
How To Grow a Catalpa Tree From Seed With Detailed Description
FAQ
Are catalpa trees easy to grow?
Overall Catalpa is a pretty great tree. It’s adaptable to many soil conditions, withstanding wet or dry soils and alkaline or acidic pH. It is a pretty tough plant that can be grown in either sun or part shade. Definitely worth considering if you have the space to compensate it’s size and messy pods.
How to start a catalpa tree from a cutting?
To propagate a catalpa tree from a cutting, select a healthy stem with new growth in late summer, cut it 4-8 inches long, and place it in potting mix. Keep the cutting moist and gradually introduce it to sunlight after it develops roots.
What are the disadvantages of the catalpa tree?
- Messy Droppings: The tree sheds large leaves, flowers, and long seed pods, creating seasonal debris.
- Weak Wood: Catalpa trees have brittle branches that can break easily in storms.