Calla lilies have been prized for centuries by flower gardeners based on their ease of cultivation, the aesthetic appeal they add to a garden and how they dress up home décor when cut and displayed in vases. They fall into a category of flowers that can be either annuals or perennials depending on the climate in which they are grown.
Annuals, as their name implies, generally have a lifespan of one season or year. The cycle starts with a seed or bulb, which turns into a flower. When the flowers fall from the blooms and die, the leaves, stems and roots follow suit. Perennials spring back to life year after year, as the top of the plant is the only part that dies while the rest of the plant nestles back into the ground and rejuvenates itself the following spring.
An annual/perennial is a plant that chooses its path based on the local growing conditions and climate. If an annual/perennial, which includes well-liked black-eye Susans as well as calla lilies, is planted in a climate that is warm for most of the year, they grow significantly quicker and have a long growing season but have to be replanted each year. Conversely, if a plant in this category is planted in a region that has four distinct seasons with great variations in temperature, it will respond like a perennial, receding underground as the temperatures fall and start to grow again as the temperatures of spring rise.
Calla lilies grow tall, between 24 and 36 inches. Their flowers present a dramatic appearance with a center spike that has a single petal curved around it. Calla lilies come in a wide spectrum of pastel and deep colors and have solid green or white-speckled leaves shaped like arrowheads.
Whether you are growing calla lilies as annuals or perennials, you will find them strong and resilient. The bulbs will grow in almost any soil as long as they get enough humidity and are watered frequently but not saturated, as the latter will cause the bulbs to rot. The plants produce many bulbs that can be dug up and planted in other areas of the garden. It is possible to grow calla lilies from seed but it is a much more challenging task. In a perfect climate, calla lilies can sometimes be encouraged to bloom year-round, although this takes fastidious care, extra nutrients and a degree of luck.