This section is from the book "Commercial Gardening Vol4", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
Probably with regard to no other crop that is grown by the market gardener does the treatment vary so much according to locality as in the case of Rhubarb (Rheum hybridum). In some places, particularly London, there is a considerable demand for the natural product, or green Rhubarb as some call it; in others, the only demand there is is restricted to the yellow-leaved forced product.
In some districts the stools are lifted, placed in sheds erected for the purpose, and heated either with flues or hot water and there forced; in others, manure is heaped around the crowns, which are covered with pots.
In some districts the crop is grown solely for forcing, and none is pulled as natural; in others, the principal crop is the natural, and only the worn-out crowns are forced.
The Rhubarb is a gross feeder, and responds especially to manures of a nitrogenous character. Its strong roots, forcing themselves into the soil, have a dynamic effect which is appreciated by after crops. Rhubarb will do in a wide range of soil characters, provided water does not stand, and it is well fed.
The method of planting is to cut sets from old stools. A set is one good eye or two weak ones. They are planted in holes opened 2 ft. 6 in. by 2 ft. 6 in. apart, and the soil pressed well round the set. The time of planting is from December to March. If the Rhubarb is planted for forcing it is left till the third or fourth year, then lifted, or forced in situ. If grown naturally it is not pulled at all the first year after planting, only a little the second year, and the third and subsequent years' pullings last until the middle of June, when the crowns must be allowed liberty to store force by leaf action for next year's effort.
Natural Rhubarb is usually bunched in flat bunches formed on boards and bound with two rods, each secured by the method called "buttoning" (fig. 490). Pulling costs 2s. to 2s. 6d. per 100 dozen, trimming 2s. 6d. per 100 dozen, binding 15s. per 100 dozen, till the leaves need docking, and then an extra 2s. 6d. must be added.
Fig. 490. - Showing Bunch of Late Rhubarb tied with Osier Rods.
The price realized varies from 4s. 6d. per dozen bunches at the commencement to 1s. per dozen bunches in the time of greatest supply.
Rhubarb is very heavy carriage, and this is a matter that a grower a long way from his market must take into consideration. For natural Rhubarb undoubtedly the best sort is the Chamjmgne. Another good sort is Dawes Champion, but it will not stand the punishing that Champagne will. These varieties are red in appearance, maintain their colour all the season, and are red when cooked. For late work in June the Victoria is a useful sort; it produces enormous sticks of a fair colour when it is three years old, but it is green when cooked.
When grown for forcing only, the Linnceus and the Victoria are most in favour, and Johnstons St. Martin has also advocates for this purpose.
Forcing takes from four to five weeks in a shed.
The heat to be maintained is 55° to 60° F. If the forcing is too sharp, a failure of colour is the result; if there is a check in growth, that is, if a higher temperature is started with than can be maintained, leaf is produced instead of stalk.
Plenty of water must be used during forcing. The Yorkshire forcers have set the fashion of little bundles of two or three sticks, which sell at 1s. 6d. to 2s. per dozen bundles early in the season. [W. G. L].
Fig. 491. - Clump of Forced Rhubarb.