Using Bulbs to Beautify Your Garden

When people think of spring, many think of all the spring flowers that welcome back the growing season with a multitude of colors. But did you know that many of these flowers grow from bulbs or bulb-like structures and the required work begins long before these plants start blooming?   

You may ask, “What is a bulb?” Bulb is a term used to describe plants that develop underground storage organs, ensuring survival. Botanically speaking, bulbs are modified stems that cradle an underground bud with fleshy or membranous leaves. Those fleshy leaves serve as a food reserve, enabling plants to stay dormant during unfavorable weather conditions, such as cold temperatures or drought. The term is used loosely and there are many types of bulbs, including true bulbs, corms, tubers, tuberous roots and rhizomes. They can be further divided into two broad groups – hardy bulbs, which bloom January through May, and tender bulbs, blooming June through September.

True bulbs include Asiatic lilies, tulip and daffodils, as well as onions. A true bulb is a miniature plant encased in modified leaves that contain food for the plant. Corms are a modified stem that also helps store food for the plant. Some corms may have a fuzzy or hairy exterior. Examples of corms include crocus, gladiolus and freesia.

Another type of bulb is a tuber. Like a corm, the tuber also is an underground stem that stores food. However, it does not have a covering of modified leaves, nor does it serve as a base of the stem. Tubers have multiple “eyes,” or growth buds, where the shoots emerge. Potatoes, tuberous begonias and cyclamen are all tubers. In the bulb group, tuberous roots are the only type that are true roots, storing food in root tissue rather than stem or leaf tissue. Daylilies, dahlias and sweet potatoes have tuberous roots. Finally, rhizomes are an elongated, thick stem that grow horizontally along or below the soil’s surface. Bearded iris, canna and calla lilies, as well as mint, are all rhizomatous plants.

Bulb Selection and Storage

When purchasing bulbs, select bulbs that are plump and firm. Be sure to investigate for signs of damage, and do not purchase bulbs that are soft or moldy. If you are unable to plant your bulbs right away, store in a cool, dry place at 60 to 65 F until it’s time to plant. Rhizomes, tubers and tuberous roots should be stored in peat, perlite or vermiculite to prevent drying out and decay.

Tender bulbs should be dug and stored once the leaves turn yellow. When digging, use a spading fork to lift them from the ground. Rinse off any soil clinging to the bulbs unless the bulbs are being stored in pots. Spread the clean bulbs in a shaded place to dry and cure for one to three days. Once dry, store at 60 F to 65 F in an area that will allow air to circulate around the bulbs. You can leave the soil on bulbs like begonias, canna, caladium and dahlias. Separate the bulbs just before planting.

Site Selection

When selecting any site for planting, it is important to consider light, soil texture, temperature and your overall goal for the area or plants. Most bulbs will thrive in full sun, meaning they should receive at least five to six hours of direct sun. Bulbs left in the ground every year, such as Asiatic lilies, crocus or tulips, will need eight to 10 hours of direct sun for more blooms.

Drainage and soil texture should also be considered when selecting a site to plant your new bulbs. Most bulbs do not perform well in wet, soggy soils and could possibly rot. In fact, you should try to wait to plant bulbs when soil is fairly dry because wet soil will pack tightly around the bulb and could reduce growth. Work soil to 8 to 12 inches and mix in organic matter. Set the bulbs upright in the hole and cover. Be sure to follow guidance on the bulb’s package to determine the correct planting depth. Generally, bulbs should be planted one-half to three-times the bulb’s diameter. However, bearded iris should be planted just below the surface.

General Care

When flowers fade, deadhead to prevent seed formation, which takes energy that the plant can otherwise store in the bulb. If you are planning to leave bulbs in the ground, like daffodils, do not cut the green leaves back until they turn yellow and wither. The green leaves continue to photosynthesize and produces food for the next year that will be stored in the bulb. Once the leaves yellow and wither, remove them to prevent disease on next year’s growth. If you plan to move bulbs or if the area is crowded and is not blooming as profusely as you prefer, dig once the foliage has faded, then separate and replant the bulbs in fall.

Container Planting

Many bulbs perform well, not only in your gardens, but in containers if space is limited. One of the methods to grow multiple bulbs in a container is by using the lasagna method. This method is used predominately with hardy spring bulbs and allows growers to showcase various bulbs in the same space. If you choose to use this method, be sure to select plants that will need planted at different depths and bloom at different times.

Be sure to follow planting depth directions on your bulb package and start with large, later-blooming bulbs, such as allium, at the bottom of your “lasagna.” Cover the first layer with potting media and plant the next bulb you plan to use. Continue until you have three to four layers of bulbs planted. This method also can be completed in the garden. If planting in a container, be sure to keep the container in a protected area all winter.

Planting depth and time: brecks.com

Bulbs can add extra blooms and color year after year to your yard and garden areas. Hardy bulbs signal spring’s arrival, while tender bulbs fill and add color and texture to your summer garden.

Sources

Faulkner, C. (2016, November 25). Understanding bulbs. ANR Blogs. Retrieved from https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=22668

Meyer, M. H. (2018). Planting bulbs, tubers and rhizomes. UMN Extension. Retrieved from https://extension.umn.edu/how/planting-bulbs-tubers-and-rhizomes#purchasing-bulbs-1410660

Sandborn, D. (2022, January 21). Planting bulbs, lasagna style. 4-H Plants, Soils & Gardening. Retrieved May 18, 2022, from https://www.canr.msu.edu/news/planting-bulbs-lasagna-style

WVU Extension Master Gardener Manual, chapter XIX, pg. 24-27. Herbaceous Plants.

Author: Jennifer Friend, WVU Extension Agent – Harrison County

Last reviewed: July 2022

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