Growing Dahlias

Dahlias are now available in many sizes and shapes. Try some of the new and attractive forms which have a wide range of colors. Get catalogs from seedsmen who handle this plant, or check with your local florist or garden center to be sure they plan to have some of the new varieties this year.

Single dahlias look like large daisies with eight white or colored petals. Collarette varieties are similar to the singles, but have an extra row of short petals around the center disc of the flower. Orchid-flowered dahlias have very graceful form with eight petals curled into attractive pointed tubes.

New colors and forms are available in the double varieties. The large decorative types have flowers which are eight to 12 inches across. Ball dahlias have compact round flowers from four to six inches in diameter. Pompon types resemble small ball dahlias, two inches or less in diameter. The cactus varieties are very attractive and are particularly useful in flower arrangements.

Dahlias can be propagated by seed but plants from seed frequently do not come true to variety. Seeds which are produced in large quantities by the single-flowered varieties are usually sold as annual mixtures. Double-flowered varieties rarely produce reliable seed. Tuberous root divisions give the showiest blooms.

Dahlias grow best in a deep, fertile, well-drained soil in a sunny location. Tubers should be spaced three or four feet apart if large exhibition flowers are desired. For small flowers in beds or for cutting, plants may be about two feet apart. The cluster of tuberous roots may be separated and planted at about the time of the last killing frost. Root divisions should be placed on their side about five inches deep. Cover with about two inches of soil and fill the remainder of the hole as the shoots develop.

For large blooms, allow only one stalk per root to develop. Remove all small weak sprouts. When the shoot is about six inches tall, pinch back to about the third set of leaves to promote branching. Only four main branches should be allowed to develop on large flowering varieties. As the stems grow they should be tied to a stake to prevent breakage. Disbudding may be practiced to secure large blooms for exhibition purposes.

Seeds of the small varieties are sown early indoors in a light-weight medium. They will germinate in 10 to 15 days at 70 degrees F. Transplant young plants into individual pots after the third true leaf develops. Plant in the garden after danger of frost has past.

Adequate moisture must be provided to promote vigorous growth and flower production in dahlias. A mulch of 1 or 2 inches of peat moss or sawdust will help conserve soil moisture during dry periods. Eliminate all weeds which would compete with the plants. Fertilize at planting time with 1/2 cup per plant of a 5-10-5 or 10-10-10 fertilizer dug into the soil. Faded flowers should be removed to encourage continuous blooming. Gardeners should be on the lookout for damage by Japanese beetles; treat if necessary.