COTTONWOOD IN THE MISSISSIPPI VALLEY. 53 
often be obtained up to the second week in June. Abundant. seed 
is produced annually. The seed should be collected just before the 
pods or capsules begin to open, although large quantities of it could 
easily be obtained later in protected places on the ground. Seed col- 
lected from the ground, however, is apt to be mixed with other 
material such as leaf litter or even with seeds of other species, par- 
ticularly of willow, which also mature early. Furthermore, ground- 
collected seed is obviously not so fresh as that in the unopened cap- 
sules; this, because of the short vitality of cottonwood seed, is a dis- 
advantage. In the case of large open-grown trees, the catkins may 
easily be picked from the tree by a man with a ladder. Where 
logging operations are in progress at this season seed can be obtained 
from felled trees at a very low cost. It is also frequently possible to 
obtain plenty of green catkins of good quality which have been 
blown off the trees by heavy winds just before opening. As a rule, 
however, the picked seeds are more dependable. 
The green “seed balls” should be kept well aerated. If stacked 
in large piles or kept in closed receptacles there is danger of their 
becoming heated and possibly losing their vitality. They should, 
therefore, be spread out to dry as soon as collected, and when they 
begin to open should be covered over with strips of paper to pre- 
vent the cottony seed from escaping into the air. As soon as the 
capsules are wide open the seeds are ready for sowing. The vitality 
of the seed lasts for only a week or two at the most. 
The nursery bed may be prepared in the same manner as for any 
other broadleaf species. The soil should be deep, moist, and per- 
meable. It should be well worked to the depth of about a foot. 
Sandy soils should be enriched and well mixed with manure. The 
surface of the beds, after being thoroughly worked, should be rolled 
smooth. 
The seed balls may be spread out on the surface of the prepared 
nursery bed as soon as they have been collected, and thus allowed to 
dry out in the sun until the pods are opened sufficiently to shed the 
seed. Best results can be obtained by collecting small branches bear- 
ing a good supply of seed catkins and laying them on the beds with 
the catkins still on them. As soon as the seed balls open the seed can 
readily be shaken out over the surface of the bed, after which it 
should be soaked down and lightly covered with a sprinkling of 
sand. After the pods have begun to open it may be necessary to 
keep the beds covered with strips of heavy paper in order to pre- 
vent the escape of the “ cotton.” The seed must be shaken out over 
the bed on a very calm day, or else beneath the paper cover. 
If the seed balls have dried previous to sowing, the seed should be 
spread as evenly as possible over the surface of the bed until it is 
entirely covered with a very thin layer of cotton. Over this dry 
