The hardy catalpa is one of the best fence post trees that can be grown in Iowa. Nearly all the catalpa plantations in the state have been studied by the forestry section of the experiment station. A large majority of them are successful, and seem to be a paying proposition for their owners.
The hardy catalpa is a southern tree, its natural locality being throughout southern Ohio, Indiana and Illinois, eastern Missouri, and southward. Iowa is considerably north of its natural range. In the southern half of the state there is very little danger of winter killing if given a favorable location. In the northern part, however, there has been considerable trouble from this cause. For this reason it is not advisable to plant catalpas in extensive plantations in the extreme northern and especially in the northwestern part of Iowa.
North of the line drawn between Harrison and Monona counties, and continued eastward across the state, catalpa plantations should be protected by a windbreak of hardier trees planted along the north and west sides of the grove. Three or four rows of cottonwoods or willows afford plenty of protection.
Scott, C. A.
"The hardy Catalpa in Iowa,"
Bulletin: Vol. 10
, Article 1.
Available at: https://lib.dr.iastate.edu/bulletin/vol10/iss120/1