Tag Archives: tubers

May Is Dahlia Planting Time

Mother’s Day signals the time to plant dahlias. Like chrysanthemums, many people associate dahlias with the fall but dahlias can bloom from the beginning of summer to frost. Dahlia flowers are available in a wide range of sizes, colors, and shapes. Each bloom can be 2 inches across to more than 10 inches, in all colors except blue. Plants can reach one to 6 feet tall. Some plants have beautiful dark foliage instead of green leaves. Although there are 40 plus species there are thousands of cultivars. In addition, there are numerous forms such as the single, peony, anemone, collerette, star or single orchid, double orchid, cactus, waterlily, ball, and pompom. Continue reading

Nurseries that Specialize in Bulbs, Rhizomes, Corms, Tubers, Etc.

bulbsA few weeks ago, I shared my list of companies that specialize in seed and asked you to send me companies I did not have so I could expand my list. I received many new companies (thank you!) so I now have 86 seed companies on my website. I thought I would do this for my list of companies that sell ornamental bulbs. These can be the spring blooming bulbs as well as summer plants that are sold by bulbs, tubers, corms, rhizomes, etc.  Those that are edible, i.e., seed potato and garlic, are on the seed list. So send me your suggestions in the comments section so we can expand this list from 19 to 30 at least!

Amaryllis and Caladium Bulb Company, Florida, has catalog and can order online. Sells amaryllis, caladiums, and spring and summer bulbs.

Brecks, Ohio, has a catalog and can order online, states that it ships bulbs directly from Holland

Bluestone Perennials, sells bulbs as well as perennials.

Brent and Becky’s Bulbs, Virginia, has a catalog, can order online, can visit display garden and shop in Gloucester, VA.

Colorblends, Connecticut. Although “wholesale” is in their title and on their website, they do sell bulbs to home gardeners. There is a $60 minimum order. They have an annual print catalog and an online site for ordering. Specializes in spring blooming bulbs.

Dan’s Dahlias, Washington state company that specializes in dahlias.

David Burdick Daffodils and More, Massachusetts, has catalog and website but not able to order online. Has daffodils, trollius, colchicums, and a few other bulbs

Dutch Gardens, Illinois, has catalog and can order online, sells bulbs and perennials

Dutch Grown, Pennsylvania, order bulbs online.

Easy to Grow Bulbs, California, can order online, no catalog. Sells bulbs, succulents, and houseplants.

John Scheepers Beauty from Bulbs, Connecticut, can order online and has catalog. Also has sister company Van Engelen for wholesale bulb orders and a sister company, Kitchen Garden Seeds, for vegetable, herb, flower seeds

Longfield Gardens, New Jersey, can order online but no catalog, sells bulbs and perennials

McClure and Zimmerman, Wisconsin, has a digital catalog and can order online, sells bulbs

Odyssey Bulbs, Massachusetts, online, no catalog, sells unusual bulbs and perennials

Old House Gardens, Michigan, can order online and has a print catalog, known for heirloom bulbs

Plant Addicts is a family owned, online plant store in Nebraska that sells bulbs as well as other types of plants and garden décor. Their website also offers gardening information and resources.

RoozenGaarde and Washington Bulb Company, Washington, has a mailorder and internet division called Tulips.com. There is a retail gift shop in WA. Also ships flowers and promotes bulbs as wedding favors.

Telos Rare Bulbs, California, sells bulbs from South Africa, South America, and western U.S., online, no catalog

White Flower Farm, Connecticut, can order online and obtain catalog, wide range of bulbs, perennials, holiday plants, and gardening tools. Has display gardens and store in CT.

Darling Diva Dahlias

Like chrysanthemums, many people associate dahlias with the fall but dahlias can bloom from the beginning of summer to frost. Dahlia flowers are available in a wide range of sizes, colors, and shapes. Each bloom can be 2 inches across to more than 10 inches, in all colors except blue. Plants can reach one to 6 feet tall. Some plants have beautiful dark foliage instead of green leaves. Although there are 40 plus species there are thousands of cultivars. In addition, there are numerous forms such as the single, peony, anemone, collerette, star or single orchid, double orchid, cactus, waterlily, ball, and pompom.

Planting Tubers or Seed

To grow dahlias, you can either purchase tubers or start them from seed. If you purchase a tuber that is a named variety you will know exactly what the plant will look like. Plus, if you purchase cultivars that have been trialed and proven to do well in this area, you will have a good chance of success.  Seed is cheaper than tubers but there is a lot of variability with plant vigor and flower color. Although the seed will grow and produce a plant with pretty flowers for the garden, the flowers may not be exhibition quality.

Tubers can be planted outside in the ground after the average last frost date (Mother’s Day in the Washington DC metro area). Tubers also can be started indoors in April in containers under fluorescent lights or by the window to initiate growth. Seed should be started indoors under lights because planting seed in cold soil may retard the germination rate. Starting seed outdoors in May will only delay the time to reach blooming stage.

Caring for Dahlias

“Put the tuber in a four-inch hole and cover so that it is just peeking through. This way you can see the growth. When it grows, add more soil,” advises John Spangenberg, member of the National Capital Dahlia Society and owner of Crazy 4 Dahlias. John is a long time dahlia enthusiast who also sells tubers from his website.

Growing a dahlia plant is similar to growing a tomato plant: full sun and plenty of water and food. A dahlia can grow in less than 6 hours of sun but would not produce as many flowers. After planting the tubers, insert stakes such as tomato cages or posts. In the beginning, dahlias will require plenty of water, generally one inch of water per week. Dahlias are heavy feeders and will need fertilizer throughout the summer. Slow release fertilizers also work well. Dahlias appreciate a leaf or straw mulch to keep the tubers cool and to prevent weeds.

Encouraging More Flowers

In the beginning of the growing season, John recommends topping the plants to encourage bushier, sturdier plants with more flowers. The center bud (not flower bud but central growth) should be pinched back. “When you see three to four sets (or pairs) of leaves, break the center top off,” explained John.

Later in the season when flower buds appear, disbud or cut off smaller, lateral flower buds to encourage the top bud to form a single, larger flower. When a dahlia flowers, there are three stems with three buds in a v-shape. When the outer two smaller buds are the size of peas they should be cut leaving the center flower bud.

“The more you cut your flowers, the more flowers you get,” said John. If you don’t cut a flower for a vase, make sure you at least deadhead them. Deadheading is cutting off and disposing flowers that are past their prime to encourage the plant to produce more flowers.

Throughout the season, make sure the plant is well staked as it grows, feed it, and make sure it gets enough water.

Saving Tubers in the Fall

Dahlias are native to Mexico. Here in Washington DC they are treated as tender perennials and may or may not come back the following year. In order to ensure that the plants can be grown again next year, most gardeners lift and store the tubers in October.

“In the fall when get the first frost, cut the plant a couple of inches above the ground and let sit for a week or dig them up,” explained John. “You want to have the eyes develop and swell to be able to see them well. It helps to see the eyes when dividing the tubers. You can divide in the spring or fall but it is easier to divide in the fall.”

Dahlia tubers are swollen roots. Each tuber has to have an “eye,” which is a growing point in order to grow. From that eye the stem will emerge. In May, a single tuber with an eye is planted for a single plant. In the fall, when the plant is lifted out of the ground, there will be more new tubers joined together in an area called the crown. The “eyes,” or viable growing points, are in the crown. This can be stored as is or divided to create more plants.

John uses vermiculite in a box to store his tubers but there are many methods to store tubers. He finds vermiculite works best because it absorbs and releases moisture. Tubers should be in the coolest place in the house where there is constant temperature such as a crawl space or basement or a closet next to the outer wall of the house.

Because they are native to Mexico, one would think that dahlias would be easy to grow here with our sunny, warm summers. In fact, dahlias are native to a mountainous region in Mexico with more wind, less humidity, and cooler temperatures. Thus dahlias grow very well in the Pacific Northwest but have some difficulty in the mid-Atlantic. They need quite a bit of water, yet as heavy feeders, the rain can leach the nutrients. Plus the humidity can encourage disease. “In this area, we have issues with slugs, earwigs, rabbits, groundhogs, and deer,” said John. “Plus we have noticed that Japanese beetles prefer white and yellow flowered dahlias.”

Selecting Dahlias for Washington DC Metro Area

To choose a dahlia that performs well here, look to the National Capital Dahlia Society for recommendations. A branch of the American Dahlia Society (ADS), the National Capital Dahlia Society is comprised of dahlia enthusiasts and breeders who meet on a regular basis. Every year they manage a trial garden at the Agricultural History Park in Derwood, MD. “The display garden is a trial garden to test new introduction from across the country to see how they do here. We look at bloom quality and plant vigor and report this to the American Dahlia Society,” said John. Later in October, the Society members will dig up the dahlias at the trial garden and demonstrate how to save the tubers (open to the public). They also sell tubers next year so if you are interested in growing dahlias that do well in the Washington DC metro area, contact them via their website: http://www.nationalcapitaldahlia.org.