Nasturtiums.--These are among the most useful of our hardy annuals,
producing a display of the brightest of colours throughout the entire
summer. The tall-growing climbers make a gay background to a border,
and are equally valuable for trellis-work, while the dwarf varieties
are first-class bedding plants, and of great service for ribboning.
The seeds may be sown in pots in September or in the open ground early
in spring. A light sandy or gravelly soil is the best to produce a
wealth of bloom. Height, 6 ft. and 1 ft.
Nectarines.--Require the same treatment as the Peach. In fact, the
Nectarine stone sometimes produces a Peach, and a Peach stone often
produces a Nectarine. Fairchild's, Humboldt, Lord Napier, and Red
Roman are useful varieties. They should stand 20 ft. apart.
Neilla.--These shrubs thrive in ordinary soil, and are increased by
cuttings of the young wood. They flower in July. N. Torreyi bears
white Spiraea-like flowers, which are very effective. Height, 6 ft.
Nemesia.--A most beautiful half-hardy annual of the Antirrhinum class.
Sow the seed early in spring on a hotbed, and plant out in May in
rich, light soil. Cuttings of the young wood will strike under glass.
Height, 1-1/2 ft. to 2-1/2 ft.
Nemophila.--Pretty, neat, and compact hardy annuals, well worth
cultivating. They succeed best in a moist and shady situation, delight
in peat or vegetable mould, and when grown in circles are very
striking. If wanted to flower early, sow the seed in autumn, or on a
hotbed in spring; and if required for late blooming, sow in the open
in March. Treated thus they flower from June to September. Height, 1
ft.
Nepeta Glechoma Variegata.--A very useful plant for hanging baskets.
It can be trained as a pyramid or allowed to hang down; in many cases
it is employed as edgings. It is of easy culture, and does well as a
window plant or in a cool greenhouse. The soil should be light and
dry. It flowers in July, and may be increased by root-division.