Catalpa, or fish bait, trees produce long bean type pods. These pods contain a moth larvae that is proven to be an excellent fish bait. While there are two distinct species of the trees, a northern species and a southern species, both appear to produce the long pods or fruits. According to Kim Coder, professor at the Warnell School of Forest Resources, the trees will begin to flower at the age of 7 years and begin to bear full-length fruit 3 years later. The fast growing tree will also provide large amounts of shade under the expansive leaves.
Collect seedpods from catalpa trees that have a proven track record of supporting the moth larvae for many seasons. The seeds are located inside the large pods. The seeds will be mature once the pods have fallen to the ground, so there is no need to climb the catalpa tree.
Remove the individual seeds from the pods. In most cases, seed planting will occur during the middle of summer to early fall depending on the pod production of the mother tree.
Prepare the garden site by working the soil, with either a rototiller or hand cultivator, to loosen the soil and remove any errant weeds.
Plant the catalpa seeds in a straight row with approximately 6 inches between the seeds.
Transplant the seedlings, during the cold winter months, when the overall stems are at least 18 inches high. This may take up to two years for the catalpa seedling tree to reach this transplant height. The transplant hole must be the same size as the root ball dug from the garden site with the shovel. Water the seedling into the soil to remove any air from around the root ball.
Mulch around the new seedling with 1 to 2 inches of organic material to retain moisture. Keep the mulch at least 3 to 4 inches away from the main trunk. Add mulch on a yearly basis. The outer perimeter of mulch should match the upper limb drip line of the tree.
Add a slow release nitrogen and phosphorus fertilizer each spring onto the mulch covering. Keep the soil pH to around 6.4. You can add dolomitic limestone to raise low pH levels. Consult your local agricultural extension service for soil test kits and procedures to accurately find your soil pH.