10 BULLETIN 974, U. S. DEPARTMENT OF AGRICULTURE. 
in the submerged lower layers of deep bogs, such as is used for fuel 
in Europe, is not suitable for blueberry-soil mixtures. 
TUBERING. 
By ordinary methods cuttings of the swamp blueberry could at first 
be rooted only in occasional instances. Successful special methods, 
however, were afterwards devised for these plants. The most novel 
of the methods devised, but the one easiest of operation, is that of 
tubering. This method involves the same principle as that employed 
in stumping, namely, the forcing of new shoots in such a manner 
that their basal portions are morphologically scaly rootstocks, with 
a strong rooting tendency. The directions for tubering as applied 
to the swamp blueberry are as follows: 
(1) Make stem cuttings from outdoor plants between midwinter and early 
spring, before the buds have begun to make their spring growth, and preferably 
on a warm day when the twigs are not frozen. A still better plan is to make 
the cuttings in autumn after the leaves have fallen and store them for about 
two months in moist sphagnum moss or clean basswood sawdust on ice at a 
temperature just above freezing. 
(2) The cuttings are to be made from vigorous plants grown in well-lighted 
situations and with stems therefore well stored with starch. Use unbranched 
portions of the old and hardened branches and stems, about a quarter of an 
inch to an inch, or even more, in diameter. From 8 to 4 inches is a suitable and 
convenient length. Make the cuts with pruning shears or a fine-toothed saw 
and remove the bruised wood at the cut ends with a sharp knife. Be careful 
not to injure the bark or split or strain the wood. 
(3) Lay the cuttings horizontally in a box about 8 inches deep in a bed of 
pure clean sand and cover them to the depth of about three-quarters of an inch 
with a mixture of sifted rotted peat (two parts) and clean sand (one part). Or 
the whole bed may be composed of sand mixed with about an equal bulk of 
peat. Or the bed may consist of a mixture of basswood sawdust and peat, 
described under “ Winter cuttings.” Moisten the bed well with rain water, 
bog water, or other pure water (free from lime) from a sprinkling pot and 
see that the bed is closely and firmly packed about the cuttings. Cover the 
box or cutting bed with a pane or panes of glass, the top of the box being flat, 
so that the glass fits it rather snugly. The box should be so prepared that any 
surplus water will drain away beneath through holes in the bottom covered 
with clean broken crocks and sphagnum moss. 
(4) Keep the box at a temperature of 55° to 65° F. or as near those limits 
as practicable. A temperature of 70° or over is likely to ruin the cuttings. 
(5) To avoid excessive temperatures, do not allow direct sunlight upon the 
glass, either keeping the box by north light or keeping it shaded, as by a white 
cloth or paper cover suspended several inches above the glass, or in a shaded 
greenhouse. 
(6) Keep the air over the bed saturated with moisture. This condition will 
be evidenced by the condensation of the moisture on the under side of the 
glass during the cooler part of the day or whenever a cold wind blows against 
the glass. 
(7) Watering should be as infrequent as practicable, only sufficient to keep 
the cutting bed moist but well aerated and the atmosphere above it saturated. 
If the glass fits tightly, a second watering may not be needed for several weeks. 
