456 MANUAL OF GARDENING 
The classes of vegetables. 
Before attempting to grow particular vegetables, it will help 
the beginner to an understanding of the subject if he recognizes 
certain cultural groups or classes, and what their main require- 
ments are. 
Root-crops — Beet, carrot, parsnip, salsify. 
The root-crops are cool-weather plants; that is, they may be 
sown very early, even before light frosts disappear; and the 
winter kinds grow very late in the fall, or may be left in the 
ground till most other cropsare harvested. They are not often 
transplanted. 
Loose and deep soil, free from clods, is required to grow 
straight and well-developed roots. The land must also be 
perfectly drained, not only to remove superfluous moisture, 
but to provide a deep and friable soil. Subsoiling is useful 
in hard lands. A large admixture of sand is generally desir- 
able, provided the soil is not likely to overheat in sunny 
weather. 
To keep roots fresh in the cellar, pack them in barrels, boxes, 
or bins of sand which is just naturally moist, allowing each root 
to come wholly or partly in contact with the sand. The best 
material in which to pack them is sphagnum moss, the same 
that nurserymen use in packing trees for shipment, and which 
may be obtained in bogs in many parts of the country. In 
either sand or sphagnum, the roots will not shrivel; but if the 
cellar is warm, they may start to grow. Roots can also be 
buried, after the manner of potatoes. Page 158. 
Alliaceous group — Onion, leek, garlic. 
A group of very hardy cool-weather plants, demanding un- 
usually careful preparation of the surface soil to receive the 
seeds and to set the young plants going. They withstand frost 
and cool weather, and may be sown very early. Seeds are 
