FOREST PLANTING IN THE LAKE STATES 17 
region. This principle would indicate either basswood, sugar maple, 
white ash, or red oak as kinds to be combined with northern white 
pine on good loamy soils. Northern white pine with white or Nor- 
way spruce may also be suggested. On the better sands and sandy 
loam soils a mixture of Norway and northern white pine may be 
recommended. 
On the jack pine-scrub oak sandy lands of the northern Lake 
States on which only Norway pine or jack pine are suitable for 
planting, it is generally necessary to plant one of these two species 
pure. Norway pine is the more desirable, except for the production 
of pulpwood. In large operations with Norway pine, however, it 
would be advisable to break up the continuous plantings by intro- 
ducing groups or strips of jack pine or even by leaving strips un- 
planted to serve as fire breaks. Where Norway and jack pine are 
planted alternately in the rows, the jack pine grows so much faster 
during the first 10 or 15 years that there is danger that it will seri- 
ously crowd and kill out the Norway pine. The oaks which grow 
naturally on these sites are probably desirable and should be saved 
to develop in mixture with the pines. 
Mixed plantings may be arranged and carried out in several 
different ways. The different kinds of trees may be planted in 
alternate rows, or alternately in each row, or in two or more rows 
of one kind alternating with two or more of the other, or in groups 
of four or more trees of one kind to a group. Other arrangements 
by which two kinds are planted in different proportions are also 
possible, but too little is known for specific recommendation. Plant- 
ing in alternate rows or strips requires only that half the planters 
have one kind and the other half the other kind of trees, and that 
they are started right at the beginning of each row so as to give 
the desired alternate or strip arrangement of the two kinds. Al- 
ternating the kinds in each row is usually done by having two 
planters work the same row. One goes ahead and plants his trees 
10, 12, or 16 feet apart, and the other follows him, putting in the 
other trees midway. These schemes do not greatly increase the cost 
over that of planting a single kind. Group planting requires more 
care and increases the cost. 
Alternate rows or alternate trees in the row give the most inti- 
mate mixture and result in the most severe competition, so that if 
one species lags behind it is likely to be seriously suppressed or 
killed. This clanger is partly avoided and at the same time many 
of the advantages of mixed planting are obtained by planting three 
or more rows of one kind, alternated with three or more of the 
other. Until more is known about the development of mixed plant- 
ings this plan is safest. 
Another method of planting mixtures is to plant first the slower 
growing kind or the one to which it is desired to give a start, and 
a few years later to fill in with the other species. This plan would 
be applicable to mixed planting of Norway and jack pine in which 
the Norway pine needs a start of three to five years to hold its own, 
but it would almost double the cost of the planting because it would 
necessitate covering the same area twice. The later planting of a 
more rapidly growing tree has practical importance, however, in 
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