Fennel.--Sow the seed in April, cover lightly with fine mould, and when the plants are strong enough set them out 1 ft. apart. Cut off the flower-stalks as soon as they appear, to prevent them running to seed. The bed will last for years. (_See also_ "Ferula.") Fenzlia.--Elegant half-hardy annuals. Sow the seed on a peat soil. If this be done in autumn, they will flower in April or May; if sown in spring, they will bloom in autumn. Height, 6 in. Ferns.--Most Ferns delight in a loose soil, an abundance of moisture, and a warm, humid atmosphere. The stove and greenhouse kinds are best cultivated in a mixture of sandy loam and peat. The hardy kinds grow best among rock-work or in a shady border: a light, sandy soil suits them. They may be increased by dividing the roots. Ferns from Seed.--Collect the spore-fronds towards the end of summer, just as the spore-cases begin to open. Place them on a sheet of paper in a box for a few days, keeping it in a dry place. Most of the spores will fall out, the others may be rubbed out with the hand. These spores will keep good a long time, but are best sown within a year. Fill the pots with good heavy loam, water freely, and apply a coating of charcoal, coarse sand, and sphragnum moss, rubbed through a fine sieve. Damp the surface, sow the spores thinly, and cover with glass. Keep the soil moist by standing the pots for a time each day up to their rim in water. No surface water should be given. Stand the pots in a warm, light place in the greenhouse, but keep them shaded from the sun. When the surface is covered with growth, prick out into pans or boxes, using a rich, light soil. When they are large enough pot them off singly in thumb-pots, re-potting as soon as these are filled with roots. Ferraria.--_See_ "Tigridia." Ferula (_Giant Fennel_).--Strong-growing, hardy, herbaceous plants. F. Gigantea has bright, glistening foliage, changing to a brilliant orange, and attains a height of 8 ft or 10 ft. F. Tingitana is very stately and graceful, growing 4 ft. high. They are easily raised from seed, will grow in any garden soil, and flower in August and September. Festuca.--An annual ornamental grass, which is grown best on a loamy soil. Sow the seed in March, and keep moist till it germinates. Height, 1 ft. Feverfew.--This hardy perennial will grow in any soil and ripen its seed freely. Young plants, obtained by sowing the seed early in spring, are very useful for edgings; when planted alternately with, or in proximity to, Lobelia a pretty effect is produced. Ficaria Grandiflora.--A hardy perennial which thrives well when planted under the shade of trees. It is increased by separating the tubers in autumn, and produces its flowers in May. Height, 6 in.