A name applied to trailing species of the genus Vaccinium (Ericdceae); much grown in North America for the fruit. Plate XXIX.

Cranberry picking in a New Jersey bog.

Plate XXIX. Cranberry-picking in a New Jersey bog.

Of the true cranberries, there are two species in North America, the small (Vaccinium Oxycoccus), and the large (V. macrocarpon). The large cranberry, V. macrocarpon (Fig. 1087), is now cultivated on thousands of acres in the United States and this cranberry culture is one of the most special and interesting of all pomological pursuits. This cranberry grows wild only in North America, where it is native to acid swamps in the cooler parts of the United States and in Canada. Here it trails its slender stems and small oval evergreen leaves over the sphagnum and boggy turf, and the firm red berries which ripen during September and October often persist on the vines till the following spring or even longer. The curve of the slender pedicel in connection with the bud just before the blossom opens, with its resemblance to the head and neck of a crane, is said to have suggested the name craneberry which is now shortened to cranberry.

The low-bush cranberry, or wolfberry (V. Vitis Idaea), is much used in Nova Scotia and other parts, and is gathered and shipped in large quantities to Boston; but it is not cultivated. This berry is also common in Europe, where it is much prized. The quantities of this fruit imported into the United States from various sources is considerable.

The ideal bog for cranberry-culture should have the following qualifications: (1) Capability of being drained of all surface water, so that free water does not stand higher than 1 foot below the surface in the growing season. (2) Soil that retains moisture through the summer, for cranberries suffer greatly in drought. (3) Sufficient water-supply to enable it to be flooded. (4) A fairly level or even surface, so that the flooding will be of approximately uniform depth over the entire area. (5) Not over liability to frosts.

The water of the streams and pools in the acid swamps or bogs, which are the natural habitat of the cranberry, is usually, but not invariably, of a brownish or amber color, and some of the most common associate plants are the swamp huckleberry or blueberry (Vaccinium corymbosum), the cassandra or leather-leaf (Chamaedaphne calyculata), the red maple (Acer rubrum) and the swamp cedar (Chamaecyparis thyoides).

There are three centers for the production of cranberries in the United States: Massachusetts, where cranberry-culture began and from which come the most berries; New Jersey second; and Wisconsin third. While the culture is in most respects similar in these three centers, each has its own characteristic methods of preparation and care of the bogs. There is also an important and growing cranberry industry in Nova Scotia.

The cranberry bog. Figs. 1088-1090.

A cranberry bog flooded in winter

Fig. 1089. A cranberry bog flooded in winter

To insure success in cranberry-culture, a prime requisite is to locate the bog on soil on which wild cranberries or some of their common associate plants flourish. This is usually a black peaty formation from a few inches to 7 or 8 feet in depth, overlying sand which in turn is frequently underlaid by a "hardpan" that is nearly impervious to water and the presence of which had much to do with the formation of the peat. Another requisite is to make sure of an ample supply of water, preferably of the brownish color, for winter flooding and for protection from frost in spring and fall. Flooding at special times is also the safest and surest weapon against many kinds of insects.

Vaccinium macrocarpon, the common cranberry. (X 1/2)

Fig. 1087. Vaccinium macrocarpon, the common cranberry. (X 1/2)

Without an ample supply of water, cranberry-culture is so hazardous as hardly to be worth undertaking. The building of the dams is the first step necessary for the improvement of a bog. A foundation for these should be made by digging a trench entirely through the peat, even if it should be 8 feet or more thick, to the clean sand, and this trench should be filled with sand free from all foreign material; above this foundation, embankments are built of clean sand and faced up with sods of live turf to prevent their being washed by the waves of the lake formed. The dams should be sufficiently high to flood the higher parts of the bog a foot deep, which will frequently make the water in the deeper parts 3 to 6 feet or more in depth. Gates or flumes must be constructed at the lowest point in these dams to provide for drawing the water off the bog and provision made for surface drainage. The latter is generally accomplished by opening the natural stream, if there should be one, or by digging an open ditch through the natural drainage center of the piece of land being improved. Side ditches should be dug leading into the stream, or main ditch, in sufficient number to drain off all surface water; they may be made from 1 to 3 feet deep, according to the character of the land to be drained.

A reservoir built above the bog is very desirable in facilitating control of the water. In frosty Wisconsin it is considered almost necessary to have three times the area of the bog in reservoir to insure the crops. If a bog is situated on a stream subject to high water, provision must be made for keeping the flood water from the bog, as the crop would be destroyed if it were flooded during blooming time or seriously injured by flooding at any time during the active growing season. Winter flooding of cranberry bogs is to prevent heaving and winter-killing. The water is put on about the first of December or after the vines have become thoroughly reddened by cold weather.

A Massachusetts cranberry bog.   Picking the fruit.

Fig. 1088. A Massachusetts cranberry bog. - Picking the fruit.

Cranberry bogs, being always lower than the surrounding land, are peculiarly liable to damage by frost, serious loss frequently occurring when an ordinary farmer would not dream of danger,and a good supply of water is the only preventive that has been found efficient. The time of starting growth in the spring may be controlled by the time the water is drained off, and the earlier spring frosts may so be avoided while an ample supply of water permits reflooding when a later severe frost threatens. Reflooding about the first of June, provided the water has not been withdrawn earlier than May 5 to 10, will also furnish protection from a number of damaging insects and will not injure the crop, provided care is taken that the water does not stand on any part of the bog more than forty-eight hours. If a bog should become seriously infested with insects later in the season, it is occasionally profitable to sacrifice what remains of the year's crop and clear the bog of insects by flooding. This sometimes results in a greatly increased yield the following year. Damage from a light frost in the fall, before the berries are picked, may be prevented by raising the water in the ditches and about the roots of the vines.

Protection from a heavy frost requires covering the plants with water, but this will cause immature berries to rot and should be done with great caution or the damage from water may be greater than it would have been from frost. During summer the irrigation of the crop is accomplished by holding the water low or high in the ditches, as the varying season may demand.