CULTURAL DIRECTIONS 
421 
588. Fertilizing. — In the fertilizing of rhubarb the 
grower should consider, (1) that the plant luxuriates in 
soils abounding in vegetable matter, (2) that large stalks 
count for good prices, (3) that the early pullings are in 
most demand, (4) that the crop of any given year de- 
pends largely upon the care of the plants the preceding year. 
Stable manure is especially valuable, because it sup- 
plies humus, conserves moisture and furnishes plant 
food. Some of the intensive and most successful growers 
use 25 or more tons to the acre. Manure is probably 
most effective when applied in the fall, although spring 
dressings are often made. 
The commercial fertilizer should contain 4 to 6 per 
cent of nitrogen and 8 to 10 per cent each of the mineral 
elements. About 1,000 pounds an acre should be incor- 
porated with the soil at the first cultivation in the early 
spring. Nitrate of soda is of great value when used at 
intervals throughout the growing season. Its use at the 
close of the harvesting season is advocated to develop 
strong roots for the next year’s crop. The same princi- 
ple is involved as in the fertilizing of asparagus. With 
proper care plantations will produce for many years. It 
is doubtful if the best profits can be realized in plant- 
ings more than five years of age. since after that time 
the stalks usually become materially smaller. The roots 
should then be divided and re-set. 
58Q. Cultivation. — Thorough tillage throughout the 
season is highly important. Enormous amounts of water 
are used by the large leaves and succulent stems, and 
conservation of moisture is urgent. At the first opera- 
tion in the spring the mulch of manure is worked into 
the soil. Subsequent tillage should be frequent, but not 
too deep. Some hand hoeing is generally necessary to 
keep the fields free from weeds. The seed stalks which 
generally appear on a small percentage of the plants 
should be broken off. 
