The Southern Catalpa (Catalpa Bignonioides) is generally described as a perennial tree. This dicot (dicotyledon) is native to the U.S. (United States) has its most active growth period in the spring . The Southern Catalpa has green foliage and inconspicuous white flowers, with a moderate amount of conspicuous green fruits or seeds. The greatest bloom is usually observed in the mid spring, with fruit and seed production starting in the summer and continuing until summer. Leaves are not retained year to year. The Southern Catalpa has a long life span relative to most other plant species and a rapid growth rate. At maturity, the typical Southern Catalpa will reach up to 66 feet high, with a maximum height at 20 years of 66 feet.
The Southern Catalpa is easily found in nurseries, garden stores and other plant dealers and distributors. It can be propagated by bare root, container, seed. It has a slow ability to spread through seed production and the seedlings have medium vigor. Note that cold stratification is not required for seed germination and the plant cannot survive exposure to temperatures below -18°F. Southern Catalpa has medium tolerance to drought and restricted water conditions.
Genus - Catalpa
Species - Bignonioides
Common name - Southern Catalpa
Pre-Treatment - Required
Hardiness zones - 5 - 9
Height - 30'-60' / 9.1m - 18.3m (50)
Spread - 20'-50' / 6.1m - 15.2m (40)
Plant type - Tree
Vegetation type - Ornamental deciduous
Exposure - Full Sun, Partial Sun, Partial Shade
Growth rate - Medium
Soil PH - Acidic, Neutral
Soil type - Clay, Loam, Well drained
Water requirements - Average Water
Landscape uses - Feature Plant, Shade Trees, Street Trees
Germination rate - 86%
Bloom season - Late Spring, Early Summer
Leaf / Flower color - Green / White
|Seeds can be soaked and sown with no pretreatment, but it could increase the germination rate.
1. Soak seeds in warm water for 12 hours.
2. Pour the seeds into a plastic storage bag with moist and sterile sand or vermiculite and place the bag into a refrigerator that maintains a temperature of 34 degrees Fahrenheit. Keep the seeds in this location for three weeks.
3. Fill a seed tray with potting soil until it reaches 1/2 inch from the top of the tray.
4. Remove the seeds from the refrigerator. Poke holes in the soil that are 1/4 inch deep and insert one Catalpa seed into each hole. Cover the holes with soil.
5. Water the soil daily and keep it constantly moist until the Catalpa seeds germinate. Afterward, water the plants when the top of the soil feels dry.
6. Wait until the plants reach approximately 3 to 4 inches tall and dig them out of the seed tray gently using your fingers. Insert one Catalpa tree seedling into a 5- to 6-inch diameter plant pot filled with potting soil.
7. Water the Catalpa seeds as needed throughout the winter months and keep them in an indoor location or greenhouse until the threat of frost has passed in the spring.
8. Select an outdoor planting location that is in full sun. Catalpa seeds will grow in all types of soil but prefer slightly moist locations.
9. Dig a hole with a shovel that is large enough to accommodate the root of the seedling and insert the roots of the Catalpa into the hole. Fill in the hole with soil and water the soil until it is moist. (source: ehow.com)