The Time for Planting 149 
Forced cool-season crops. Many varieties of head 
lettuce, pe-tsai, and spring varieties of cabbage, 
kohl-rabi, cauliflower, and celery mature properly only 
in cool weather. But they require so long a period for 
growth that if seed is sown in the open garden, hot 
weather arrives before the crop is grown. The gardener 
meets this condition by starting seedlings indoors or in 
cold frames or hotbeds so that he may have sturdy seed- 
lings 5 or 6 weeks old ready for transplanting into the 
garden about the date of the latest frosts, or if especially 
“hardened,” even before that time. 
All these crops will thrive in localities where the 
summers are cool, and in such places crops can often 
be grown during summer. Local conditions of soil and 
climate may also favor cool-season crops. A clay soil 
is often a “cool soil.’”’ A soil poorly drained in spring 
may be cool and well supplied with water in summer. 
A northern slope sometimes gives a good location for cool- 
season crops. 
The late crops of these vegetables are usually grown 
from varieties especially suited to autumn conditions. 
But these usually require a longer period of cool weather 
than is available in autumn, at least in the northern 
states, where killing frosts may occur early in September. 
In the North the autumn crops of these vegetables are 
most successfully grown as follows: 
The seed is sown in outdoor seed beds or in cold frames 
in mid spring, after the cold frames have been emptied of 
the plants grown for early plantings. Here they can be 
well supplied with water and given the partial shade 
that is necessary. The plants are then transplanted to 
