BLUEBERRY 



BLUEBERRY 



517 



easiest of operation is that of "tuboring." This method 

 involves the same principle as that employed in stump- 

 ing, namely the forcing of new shoots in such a manner 

 that their basal portions are morphologically scaly 

 rootstocks, with a strong rooting tendency. This 

 method of projiagation from stem cuttings is called 

 tubering because the treatment as well as the behavior 

 of the cuttings is essentially identical with that which 

 takes place in reproduction from tubers, as in the case 

 of the potato. 



The cuttings are made in late winter or early spring, 

 and the whole plant may be used, including old stems 

 an inch or more in diameter. With a saw and knife 

 cut the wood in pieces about 4 inches long. Lay these 

 horizontally in a shallow, well-drained box containing 

 a bed of clean sand and cover them with half an inch 

 of the same material. Water the sand well, cover the 

 box with glass, and keep it at a temperature of 60° to 

 65°, or less if the equipment does not permit the main- 

 tenance of such a temperature. The sand-bed must be 

 kept moist, although if there are only slight apertures 

 beneath the glass, a second watering may not be 

 required for several weeks. 



At the temperature already specified, shoots should 

 begin to appear above the sand within six weeks. The 

 boxes should then be placed in good light but pro- 

 tected from direct sunlight, and, when warm weather 

 approaches, they should be given the coolest situation 

 available so as to keep the temperature below 6.5° as 

 long as practicable. When the first shoots have stopped 

 grow ing and their foliage has turned to a mature green 

 color, they are ready to produce roots. A half-inch 

 layer of finely sifted rotted peat should then be added 

 to the surface of the sand-bed and thoroughly wet 

 down with a fine spray. The box should remain in 

 this condition, with a little ventilation but a saturated 

 or nearly saturated atmosphere, until new shoots cease 

 to appear. Meanwhile, during the spring and early 

 summer the older shoots will have formed roots between 

 the surface of the ground and the point at which they 

 sprang from the cutting. After a shoot is well rooted it 

 will make secondary twig-growth, and if the develop- 

 ment of roots has not already been ascertained by 

 direct examination, the making of such secondary 

 growth is good evidence that rooting has actually 

 taken place. If the rooted shoots have not already 

 disconnected themselves from the dead cuttings they 

 should be carefully severed with a sharp knife. They 

 are then potted in 2-inch pots in the standard blueberry 

 soil mixture already described, and during a period of 

 three or four weeks they should be gradually changed 

 from their saturated atmosphere and full shade to open 

 air and half sunlight. If preferred, the shoots may 

 remain in the original cutting-bed until the following 

 spring, before potting, the cutting-bed being exposed to 

 freezing temperatures during the winter. 



When blueberry plants, either large or small, are 

 grown in porous pots, the surface of the pot should 

 never be allowed to become dry, for the rootlets, which 

 grow through the soil to the wall of the pot for air, 

 are exceedingly fine and easily killed by drying, 

 to the great injury of the plant. This danger may 

 be eliminated by plunging the pots to the rim in a 

 well-drained bed of sand, or by setting the pot in 

 another pot of 2 to 4 inches greater diameter, with 

 a packing of moist sphagnum between, and crocks at 

 the bott^jm. 



A burning of the young leaves and growing tips of 

 twigs is often produced by the hot sun from the rfiid- 

 dle of June to the middle of September. Plants in pots 

 or nurserj- beds are easily protected from such injury 

 and forced to their inaximum groui.h by a half-shade 

 covering of slats, the slats anfl tlic spaces between 

 being of the same width. On cloudy days the shade 

 should be removed. It should not be used in fall or 

 pring. 



During the winter the rooted cuttings or one-year- 

 old plants should be kept outdoors, exposed to freezing 

 temperatures, their soil mulched with leaves, prefer- 

 ably oak leaves. When kept in a warm greenhouse 

 during the winter they make no growth before spring. 

 Even then their growth is abnormal, often feeble, or 

 sometimes deferred for a whole year. 



Plants from cuttings or rooted shoots are ready for 

 permanent field planting when they are two or three 

 years old and about 1 ' 2 to 2 feet high. They are best 

 set out in early spring before the buds have begun to 

 push. 



The field planialion. 



It is a curious fact that these plants send out no new 

 roots in spring until they are in full leaf, their flowering 

 is nearly or quite finished, and their principal twig- 

 growth has ceased. It is important, therefore, in tak- 

 ing up either a wild or a cultivated plant from the open 

 ground, that as much as possible of the old root-mat 

 be lifted with the plant, for upon this they depend 

 for moisture until their new rootlets are formed. 



In the case of mature wild bushes with very large 

 root-systems, when it is practicable to secure but a 

 fraction of the root-mat, say a disk only 3 or 4 feet in 

 diameter, it is the best procedure to cut all the stems to 

 the ground at the time of transplanting. The bush will 

 then produce a new and symmetrical top of a size 

 suited to the capacity of the roots. The wood that is 

 removed may be used for cuttings if the plant is suffi- 

 ciently valuable. 



A plant pollinated with its own pollen, or with pol- 

 len from its asexual offspring, produces fewer, smaller, 

 and later berries than a cross-pollinated plant. In a 

 field of plants propagated from cuttings or layers, two 

 parent stocks should be used, a row of plants from one 

 stock being followed by a row from the other. 



In the permanent field plantation the bushes should 

 be set 8 feet apart each way. When they reach mature 

 size they will nearly or quite cover the intervening 

 spaces. 



To secure full vigor of growth, the ground between 

 the bushes must be kept free from all other vegetation. 

 On rocky uplands a continuous mulch of oak leaves, 

 when it is practicable to secure them, will help toward 

 this end as well as keep the soil in the necessary acid 

 condition. It is more economical, however, to choose 

 such a location for the plantation as will permit the use 

 of horse-drawn machinery, and will make mulching 

 unnecessary. 



The most favorable location for blueberry-culture is a 

 boggy area with a peat covering and sand subsoil, the 

 peat preferably of such a thickness that a deep plowing 

 will turn up some of the underlying sand. 



The land should be so ditched that the water-level 

 can be kept at least a foot below the surface of the 

 ground during the growing season or can be raised for 

 subirrigation during a drought. 



The ground should be plowed to the depth of about 

 8 inches and repeatedly harrowed during the sea.son 

 preceding the planting, in order to kill the vegeta- 

 tion. After the plants are old enough to have formed 

 a root-mat, the harrowing should be very shallow, 

 not more than 2 or 3 inches, so that the roots will 

 not be injured. 



By proper manipulation in the greenhouse, seedling 

 blueberry plants can often be made (o ripen a few ber- 

 ries in less than a year, but they do not come into com- 

 mercial bearing in field plantations until they are 

 about five years old, when the plants are 3 to 4 feet 

 high. They then increase slowly to full size and fuU 

 bearing. 



The field plantings resulting from the recent experi- 

 ments in blueberry culture are too young to show the 

 mature yield. I'ortunately, however, there has been 

 found, near Elkhart, Indiana, a small blueberry plant- 



