162 Gardening 
ranged in a form useful for ready reference in the chart 
on page 350. 
Practical use of these maps and charts. Judging the 
probable date of the latest frost in spring helps the gar- 
dener to determine when to prepare hotbeds and cold 
frames and when to sow seeds for plants that are to be 
transplanted to the garden. 
Knowing the temperature needs of the various crops 
and the probable or average date of latest frost helps the 
gardener to judge when to plant seeds or transplant 
seedlings in the open ground during spring. 
Knowing ‘also the probable date of the first frosts in 
autumn and the length of time the crops require for 
maturity will enable the gardener to plant for late or 
follow crops at the best time. 
Local records of frost dates. The gardener should 
keep an accurate record of the frost dates — the earliest 
in autumn and the latest in spring — from year to year. 
Such a record can easily be kept at the public school 
of the locality in connection with garden work, or with 
studies of physical geography or elementary science. 
Reliable local records give an opportunity to correct 
the general maps, which cannot show local conditions. 
The longer such records are kept, the more valuable 
they become for judging the average or probable dates 
of frost. In connection with these records, it will be 
helpful to keep notes regarding varieties planted, plant- 
ing dates, date when first of crop is gathered, quantity 
and quality of yield, and special treatment given in 
respect to culture or fertilizers. Such data will help the 
gardener later, in planning for the next year’s garden, in 
