Gorgeous geophytes

Do you know what tulips, freesia, irisgladiolus, and lilies have in common?  Yes, they are all flowers, but the deeper, more fundamental commonality is that each one is a flowering bulb.

 Tulip bulbs

Tulip bulbs

Geo+Phyte = Earth+Plant

While the word geophyte sounds like something you would call a pundit or a politician, it’s simply the overarching term for any plant with a large underground storage organ, which is commonly referred to as “the bulb.”  True bulbs (tulips, iris, and lilies) consist of layers of modified leaves and a shoot in its center.  However, this organ can come in different forms—when it is built like a thickened underground stem, it is called a tuber (think potatoes, calla lilies); when it is built like a bulb, but with additional nodes,  it is known as a corm (think freesia; gladiolus).

No matter what underground form a geophyte may take, a bulb is a perfect, self-contained little world.  It is able to store food and nutrients which allow for rapid growth and its hardiness gives it the capability to survive frost and other harsh environmental conditions.

Here's a closer look at what's inside:

 Parts of a "true bulb"

Parts of a "true bulb"

Chasing the Climate Cycle

Bulbs cycle through vegetative and reproductive growth stages that look something like this: planted in the cool of the fall, a bulb will send out roots into the soil.  Tulips, in particular, need 13-15 weeks of cool weather to help establish strong roots. If the winter is particularly cold, freezing temperatures may halt the growth of the roots but will not kill them. Left to their own devices, bulbs can last quite a long time.

 Sprouting tulip bulb

Sprouting tulip bulb

When spring arrives, the warmer weather reawakens the bulbs and they send their shoots out towards the sky and over a few weeks, they begin to flower. Certain environmental conditions are needed to trigger the transition from one stage to the next, such as the shift from a cold winter to spring. If you grow bulb flowers year-round, you must mimic the seasons and trick the bulbs to behave through control of temperature and light.  Despite geophytes diminutive size, they certainly do not lack in complexity.