La Feria News

Types of bulbs suited to our year round growing season


An excellent type of perennials to grow in our Lower Rio Grande Valley are bulbs. Our mild winters suit many bulbs for growing outside in the ground. Most soils that are well-drained grow bulbs well. Our year-round growing season is perfect for all but the bulbs that need a dormant season.

Caladiums are tubers with heart shaped colorful leaves. Grown for these leaves, you should pinch off flower buds. They prefer shade and warm weather! Photos: Ann Johnston / LFN

There are 5 types of bulbs:

• Onions, garlic, tulips, and amaryllis are True Bulbs. They have a tissue papery skin called a “tunic” that protects the bulb. The bulb grows outward from the middle in circular rings that provide food for the plant.

Suggestion: Cut open an onion from top to bottom and compare to the diagram supplied for this article.

• Corms look like true bulbs but they don’t grow in outward circular rings. They are solid inside like a water chestnut. The top side of a corm has the appearance of a bullseye with buds coming out of the center top. Baby corms (cormels) grow down around the roots at the bottom. Some corms are waterlilies, gladiolus, coccus, and freesias.

Shell ginger is a rhizome grown for its leaves. It enjoys sun and spreads easily.

• Another type is rhizomes. They have elongated underground stems. They sometimes appear above ground like cattails. The roots grow horizontally underground and spread easily. Canna lilies, mint, Bermuda grass are all rhizomes. They can become invasive.

• Tubers are underground stems but not a stem base like corms. Multiple “eyes” (buds) are scattered over the tuber surface as in potatoes. They are flowering plants but prefer spring time sunlight and temperatures in the Valley. They are usually grown as annuals here. Examples are potatoes, begonias, cyclamen, anemones and oxalis.

Tuberous roots form their roots around a central stem. Sweet potatoes, dahlias, agapanthus, and daylilies are all tuberous roots.

The showy Blood Lily, South African Pincushion flower, or Fireball Lily is a bulb that can grow in the ground or a pot. It sends up its flower in the early spring before any of its leaves appear. So mark the spot where it is planted!

• Suggestions: There are many catalogues by mail or on-line to help you find different examples of bulbs usually not available at local garden stores. Oakes Daylilies and K. Van Bourgondien are but two reputable sources. is a wonderful site offering heirloom bulbs.

These catalogues and websites will also give you histories of the bulbs that are very interesting. For instance, daylilies were documented in China for thousands of years before they were carried over to Europe. They didn’t come to North America until the mid-twentieth century.

Come again next week through the Garden Gate for more hints and suggestions for gardening in our Magic Valley.

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