All About Bulbs and Other Underground Plant Structures
Introduction
Plants can reproduce in many ways, including through seeds and underground structures like bulbs, corms, rhizomes, tubers, and tuberous roots. These structures store food and energy to help plants grow and survive.
What is a Bulb?
A bulb is an underground storage structure that contains both the genetic material for the plant and a food supply to get it started. There are five different types of bulbs, but only one true bulb.
True Bulbs
True bulbs are layered structures filled with plant carbohydrates and have a shoot in the core. They also have a basal plate where roots grow, fleshy scales or layers, an outer skin, and a shoot at the center flanked by developing bulblets. Common spring bulbs, like daffodils and tulips, are true bulbs.
Tunicate Bulbs
Tunicate bulbs have an outer skin or tunic that protects the interior scales where the food sources are stored. Tulips are a good example of this type of bulb.
Imbricate Bulbs
Imbricate bulbs, like lilies, do not have a paper covering. This type of bulb must stay moist prior to planting.
Other Underground Plant Structures
Corms
Corms are similar in appearance to bulbs but are solid inside. Crocosmia, gladiolus, crocus, and freesia all grow from corms.
Tubers
Tubers are swollen stems with growth nodes or eyes. Daylilies and cyclamen are examples of tuber types of flower bulbs. Tubers are propagated by planting a piece of the tuber with several healthy eyes.
Tuberous Roots
Tuberous roots are thickened roots that hold food sources. Tuberous begonias are a common example.
Rhizomes
Rhizomes are underground stems that store plant food and can sprout new growth. Common plants with rhizomes include irises. Rhizomes can be easily pulled apart to start new plants.
Bulblets/Bulbils
Bulblets or bulbils are tiny round organs found growing on the tops of Alliums and related plants.
Choosing the Right Bulb for Your Garden
When choosing bulbs for your garden, consider the following factors:
- Climate
- Soil type
- Sunlight requirements
- Bloom time
- Height
- Color
Planting and Care
Bulbs should be planted in the fall, about 6-8 weeks before the first hard frost. Plant them pointy side up, about twice as deep as the bulb is tall. Water the bulbs well after planting.
Bulbs need well-drained soil and full sun to partial shade. They should be watered regularly, especially during the growing season.
Storing Bulbs
Bulbs can be stored over the winter in a cool, dry place. They should be kept in a paper bag or cardboard box and checked periodically for any signs of rot or decay.
Conclusion
Bulbs and other underground plant structures are essential for the growth and survival of many plants. By understanding the different types of bulbs and their needs, you can choose the right ones for your garden and enjoy their beauty for years to come.
