This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
This is a very pretty and interesting group of hardy bulbs from California. Though perfectly hardy, they are impatient of wet stagnant soil. A rich, deep, well-drained, sandy loam suits them best, and the extremes of light gravelly or clay soils are equally inimical to their wellbeing. In all cases where the natural soil is not proper for these beautiful but somewhat coy bulbs, it should be improved by adding peat and sand to the tenacious class, and loam and peat to the gravelly class, in requisite quantity, or in proportion as in either case it is deficient in body or possesses it in excess. Formerly these Brodiaeas were cultivated in pits or frames along with other classes of so-called frame-bulbs, either planted out or in pots, under the impression that they needed protection. Protection they do not require when they are at rest, except it be in the shape of a mound of coal-ashes or tan over the spot the roots occupy; and should the growth appear above ground in spring before the danger of frost is quite over, the necessary protection can be given in the open ground. A warm well-sheltered border is desirable in order to grow them to the best advantage; sunny sheltered nooks about shrubberies and rock-work are very suitable positions for them.
They should not be disturbed every year, but be left for two or three years in the same spot if doing well, and need only be lifted for the purpose of dividing them and refreshing the soil. Like all bulbs, though impatient of stagnant moisture, they need very liberal supplies of water in the growing season.
This is a gem recently introduced as new, though not really new for cultivation; it has for many years been lost sight of, and we are indebted to Messrs Backhouse of York for its reintroduction. In a mass it forms tufts of grass-like foliage, whence spring the long slender flower-scapes, which rise to the height of about 18 inches, terminating in a numerous umbel of pendant bell-shaped crimson flowers, tipped with yellow and green. It blooms in June and July.
This sort grows to the height of about 9 inches or 1 foot, bearing a compact umbel of bright blue flowers, which open in July.
This differs from the last sort chiefly in the character of the umbel, which is looser, and in the larger size of the flowers; it is about the same in height, and the flowers open about the same time.