600 IOWA DEPARTMENT OF AGRICULTURE 



LENGTH OF ROTATION FOR THE CATALPA. 



A careful study of the catalpa plantations "within the state indicates 

 that the catalpa must be handled on a sixteen or eighteen year rotation. 

 At this age the trees are still sound, and are large enough to cut two 

 posts each. The trees do not reach their full growth at this age hut 

 any further increase in growth is not enough to balance the risk of losing 

 the crop by an attack of fungus. 



SECOND CROP. 



If the trees are cut while they are in a thrifty condition, vigorous 

 sprouts will arise from the stumps and yield a second growth of posts 

 in about twelve or fourteen years. This second crop of posts will prac- 

 tically equal the first cutting in number and value. They will be straighter 

 and have fewer limbs than the posts of the first cutting, and will be every 

 bit as durable. 



To secure a good growth of sprouts the trees should be cut in February 

 or March. The stumps should be left not more than 6 inches above the 

 ground, and cut smooth with the slant all in one direction. A low cut 

 stump produces a more vigorous sprout. Early in June the sprouts should 

 be thined to one to each stump. The sprout that is left to grow into the 

 future tree should be the strongest and best arising from the stump. In 

 July or August it may be necessary to make a second thinning to cut off 

 all sprouts that start after the first thinning. After the second thinning 

 the plantation will need but little attention until the trees are ready to cut 

 for posts. 



A profitable second crop cannot be obtained if the trees of the original 

 planting are allowed to grow until they become infected with fungus. 

 Where the trees have been affected with the fungus a second crop should 

 not be planted in the same ground for some time. The spores retain their 

 vitality for several years. 



TIME OF CUTTING. 



Posts cut in November or December and piled in open ricks will dry 

 slowly without severe season checks. By the next summer such posts 

 will be thoroughly seasoned and ready for use. If a second crop is to be 

 grown from the old stumps, better sprouting will be obtained if the trees 

 are cut in February or March. The posts cut at this time will be ready for 

 use by fall. Midsummer is not a good time to cut posts as they check 

 severely in seasoning. These checks sometimes extend to the pith, 

 weakening the posts and making a place where rot can start readily. 



SEASONING. 



To air dry posts and poles thoroughly will require from six to nine 

 months' time, depending upon the season and also upon the size of the 

 posts. The posts can be seasoned quickly and satisfactorily by placing 

 in an open pile in alternating tiers of 3 and 7 posts each. The order 

 of piling admits an abundance of light and a free circulation of air. 

 The bark of the catalpa is quite thin and does not interfere to any great 



