Cuttings
No herbs are so easy to propagate by means of cuttings as spearmint,
peppermint, and their relatives which have underground stems. Every
joint of these stems will produce a new plant if placed in somewhat
moist soil. Often, however, this ability is a disadvantage, because the
plants are prone to spread and become a nuisance unless watched. Hence
such plants should be placed where they will not have their roots cut by
t
ols used close to them. When they seem to be extending, their borders
should be trimmed with a sharp spade pushed vertically full depth into
the soil and all the earth beyond the clump thus restricted should be
shaken out with a garden fork and the cut pieces of mint removed.
Further, the forked-over ground should be hoed every week during the
remainder of the season, to destroy lurking plantlets.
The other perennial and biennial herbs may be readily propagated by
means of stem cuttings or "slips," which are generally as easy to manage
as verbenas, geraniums and other "house plants." The cuttings may be
made of either fully ripened wood of the preceding or the current
season, or they may be of firm, not succulent green stems. After
trimming off all but a few of the upper leaves, which should be clipped
to reduce transpiration, the cuttings--never more than 4 or 5 inches
long--should be plunged nearly full depth in well-shaded, rather light,
porous, well-drained loam where they should remain undisturbed until
they show evidences of growth. Then they may be transplanted. While in
the cutting bed they must never be allowed to become dry. This is
especially true of greenwood cuttings made during the summer. These
should always have the coolest, shadiest corner in the garden. The
cuttings taken in the spring should be set in the garden as soon as
rooted; but the summer cuttings, especially if taken late, should
generally be left in their beds until the following spring. They may,
however, be removed for winter use to window boxes or the greenhouse
benches.
Often the plants grown in window boxes may supply the early cuttings,
which may be rooted in the house. Where a greenhouse is available, a
few plants may be transplanted in autumn either from the garden or from
the bed of summer cuttings just mentioned, kept in a rather cool
temperature during the winter and drawn upon for cuttings as the stems
become sufficiently mature. The rooting may take place in a regular
cutting bench, or it may occur in the soil out of doors, the plantlets
being transplanted to pots as soon as they have rooted well.
If a large number of plants is desired, a hotbed may be called into
requisition in early spring and the plants hardened off in cold frames
as the season advances. Hardening off is essential with all plants grown
under glass for outdoor planting, because unless the plants be inured to
outside temperatures before being placed in the open ground, they will
probably suffer a check, if they do not succumb wholly to the
unaccustomed conditions. If well managed they should be injured not at
all.