Polygala Dalmaisiana.--This showy evergreen shrub needs a greenhouse
treatment. Soil--three parts peat, one part turfy loam, and a little
sand. It flowers in March. To increase it, top the shoots, which will
cause it to throw out new ones. Take the new growth off when it is 3
in. long, and place it under glass in a propagating house. Height, 1
ft.
The hardy annual varieties of Polygala are obtained by seed sown in
peat. These flower at midsummer. (See also "Solomon's Seal.")
Polygonatum.--These pretty herbaceous plants are quite hardy. The
flowers, which are borne in May or June, are mostly white. Plants
succeed best in a rich soil. They may be raised from seed, or the
roots can be divided. Height, 1ft. to 3 ft.
Polygonum Brunonis (Knotweed).--This strong-growing creeping
perennial plant is not particular as to soil so long as it can enjoy
plenty of sunshine. The shoots root of themselves and must be kept in
check, else they will choke other things. It flowers in August, after
which the leaves assume beautiful autumnal tints. Height, 1 ft.
Pomegranate.--This requires a deep, loamy soil and a warm, airy
situation. May be propagated by cuttings of the shrubs or the root,
putting the cuttings into light, rich soil, or by layers. The double
kinds of Punica, or Pomegranate, should be grafted on to the single
ones. There is a dwarf kind, bearing scarlet flowers in August, which
requires heat.
Poppies.--See "Papaver" and "Stylophorum."
Portulaca.--The seeds of the hardy annual species of this genus may be
sown in a sheltered open spot in spring. The half-hardy annuals should
be sown thinly in boxes during March and placed in gentle heat. Harden
off and plant out in May, as soon as the weather permits, in a light,
dry soil where it can get a good amount of sunshine. Its brilliant
and striking colour admirably adapts it for small beds, edgings, or
rock-work; and it will succeed in dry, hot sandy positions where
scarcely any other plant would live. It flowers in June. Height, 6 in.
Potatoes.--Ground intended for Potatoes should be dug deeply in the
autumn, thoroughly drained, well manured and trenched, and left rough
on the surface during the winter. At the beginning of February stand
the tubers on end in shallow boxes, and expose them to the light to
induce the growth of short, hard, purple sprouts. Allow one sprout to
each tuber or set, rubbing off the rest. They may be planted at any
time from the end of February to the end of March in rows 1-1/2 to
2-1/2 ft. asunder, placing the sets 6 in. deep and from 6 to 9 in.
apart. As soon as growth appears keep the ground well stirred with the
hoe to prevent the growth of weeds, and when the tops are 4 to 6 in.
high ridge the earth up about them. Directly flower appears, pick it
off, as it retards the growth of the tubers. They should be taken up
and stored in October. If short of storage room dig up every other row
only, and give the remaining ridges an additional covering of earth.