12 MISC. PUBLICATION 43 4, U. S. DEPARTMENT OF AGRICULTURE 



Where this method is impossible because of undergrowth, small- 

 fruited species such as choke cherry must be hand-picked before falling. 

 Such species as walnut, honeylocust, and Osageorange may be 

 gathered from the ground after falling, since the fruit is large and 

 easily visible. The winged seed of elm and ash are best collected on 

 quiet days in a large, light tarpaulin or square of cheesecloth tied at 

 the corners of bamboo poles. This is moved about beneath the trees, 

 raised or lowered as the seed is flailed or shaken down. Sweeping elm 

 seeds from pavements is a common commercial method of obtaining 

 this species at low cost but only commendable when all the parent 

 trees are desirable specimens. 



Some species must be watched closely to determine exactly the right 

 time for collection. The seed of some species, notably elm and Sibe- 

 rian pea-tree, falls as soon as ripe and must be collected immediately 

 upon maturation. Seed of certain other species, although retained, is 

 relished by rodents and birds and can only be salvaged by careful 

 watching and prompt collections. 



A number of deciduous species do not develop their fruits evenly, 

 and at certain periods these may be found in all stages from green to 

 ripe. An outstanding example in the prairie-plains region is the 

 Russian mulberry, from which repeated collections every few days are 

 desirable, over a period of 2 to 3 weeks. The ripe fruit may be 

 gathered by lightly shaking the branches at each visit. 



Other species which ripen unevenly but somewhat more promptly 

 are honeysuckle, plum, and chokecherry. Where one collection is to 

 be made in a given locality, it is best to delay until the bulk of the 

 fruit has ripened faiily well, even though a part of the earlier-ripening 

 fruit may be lost. Too early collection may result in the gathering of 

 a large amount of unripe fruit. 



For species that hold their seed into the winter, collection costs can 

 be lowered considerably by delaying gathering until after the leaves 

 have fallen, at which time the seed is easily visible and is also more 

 readily detached or shaken loose. Kentucky cofTeetree, hackberry, 

 soapberry, black locust, and green ash are among those that may be 

 handled in this manner. 



Provident nurserymen make a practice of collecting a consider- 

 able surplus in good seed years and carrying it over for use in years of 

 partial or complete failure. 



All seed ciops are variable in quantity and quality from year to year, 

 just as field crops are, but sometimes for different reasons. Certain 

 species such as hackberry, Siberian pea-tree, ponderosa pine, and red- 

 cedar produce very light seed crops in some years and the cost of 

 collection may then be 5 to 10 times as high as in good seed years; 

 or the seed crop may fail entirely. Consequently, it is a good policy 

 to carry over a surplus of seed as insurance against crop failure and 

 for the maintenance of a uniform nursery production schedule. 



In the case of species which are usually fall sown, an additional 

 reason for carrying over a surplus of seed is the fact that it is often 

 impossible to collect and extract such seed early enough to sow much 

 of it the same year. Hackberry and redcedar are examples of such 

 species. 



