Blooming crocuses signal spring's arrival

Once crocuses poke their heads out of the earth, it's certain spring is not far behind.

These colorful, cup-shaped flowers are one of the earliest-flowering of the spring bulbs. But there are fall-blooming crocuses as well, which makes it hard to decide when to write about these delightful plants.

(Just to muddy the waters a bit, if you want crocuses to bloom in the spring, you need to plant them in the fall. You may want to clip this article and save it as a reminder of what to plant come September or October.)

For today's column, we'll focus on the spring-blooming type. Crocuses are perennial plants, and although they are usually called bulbs, their underground storage organ is actually a corm. Corms, which look somewhat like bulbs, are modified stems with buds that allow the plants to propagate.

According to legend, the Greek gods Zeus and Hera loved each other so passionately that the land where they lived burst open with crocuses. The plants, which are native to the region bordered by Spain to Afghanistan, were prominent in Egyptian, Greek and Roman civilizations. Today they are grown worldwide.

Native crocuses have been grown in gardens since the 1500s, when they were brought to Holland from the Roman Empire. By 1620, new garden varieties, such as the cream-colored crocus, were developed; these are similar to varieties still sold today. Victorian gardeners loved these plants and created entire carpet-beds of them.

Crocus corms vary in size and shape, and they help the plants survive the hot, dry summer dormancy periods. Each season, a new corm develops on top of the old one. Smaller corms develop on the edges and help multiply the plant clusters.

Gardeners should separate the overcrowded clumps and replant them every few years. Otherwise the flower size goes down or the plants stop blooming. This separation should be done after the foliage begins to wither in the spring — or if you mark their location, they can be dug up and divided in the fall.

Crocuses usually have leaves with a distinctive central white stripe. The flowers have six petals in two whorls of three, and the outer set is often slightly larger. Bees, moths and beetles pollinate the plants, and the flowers often have a delicious honey scent.

Flowers come in blue, brown, purple, white and yellow. Their height ranges from 3 to 6 inches, so they should be planted where they will not be hidden by other plants or landscape features. Space them three to four inches apart and they will multiply and fill in.