Menziesia (Irish Heath).--This evergreen thrives best in fibrous
peat to which a fair quantity of silver sand has been added. While
excessive moisture is injurious, the plant must not be kept too dry;
the best condition for it is to be constantly damp. Slips torn off
close to the stem will root in sand under glass, placed in gentle
heat. Height, 2 ft.
Mertensia.--These hardy perennials flower from March to July. They
will grow in any garden soil, but do best in peat, and are propagated
by division. They make fine border plants. Mertensia Maritima and
M. Parviflora, however, are best grown in pots, in very sandy soil,
perfection being afforded them during the winter. Height, 11/2 ft. to 2
ft.
Mesembryanthemums (Ice Plants).--These half-hardy, annual succulents
have a bright green foliage covered with ice-like globules. They must
be raised in a greenhouse or on a hotbed, sowing the seed in April on
sandy soil. Prick the young plants out in May. If grown in pots they
thrive best in a light, sandy loam. In the border they should occupy a
hot and dry situation. Keep the plants well watered until established,
afterwards give a little liquid manure. May be increased by cuttings
taken in autumn. Cuttings of the more succulent kinds should be
allowed to dry a little after planting before giving them water. A
dry pit or frame is sufficient protection in the winter; they merely
require to be kept from frost. Flower in July. Height, 1 ft.
Mespilus.--For treatment, see "Medlars."
Meum Athamanticum.--A hardy perennial with graceful, feathery green
foliage, but of no special beauty. It is a native of our shores, will
grow in any soil, blooms in July or August, and is freely propagated
by seeds. Height, 1-1/2 ft.
Michaelmas Daisies (Starworts).--A numerous family of hardy
herbaceous perennials. Some few are very pretty, while others can only
be ranked with wild flowers. They thrive in any soil or position, but
flourish best where there is a due proportion of sunshine. They are
easily raised from seed, sown early in spring, or may be increased
by root-division either in the autumn, as soon as they have done
flowering, or in the spring. They vary in height from 1 ft. to 5 ft.
Michauxia Campanuloides.--This is an attractive border biennial,
bearing from March to June white campanula-like flowers tinged with
purple, on erect stems. It is not particular as to soil, but requires
a southern position and protection in winter. Propagated by seeds in
the same way as other biennials. Height, 4 ft.
Mignonette.--For summer-flowering plants sow the seed in spring, and
thin out to a distance of 9 in. apart. To obtain bloom during the
winter and spring successive sowings are necessary. Let the first of
these be made the second week in July in light, rich soil; pot off
before frost sets in, plunge them in old tan or ashes, and cover with
a frame facing the west. Another sowing should be made about the