JARS v39n1 - My Experience Using Alfalfa as a Growth Stimulant for Rhododendron Seedlings

My Experience Using Alfalfa as a Growth Stimulant for Rhododendron Seedlings
Joe Davis, Sumner, WA

Reprinted from Seattle Chapter Newsletter

Seed was planted on February 6, 1982 in "no damp off moss", which is ground sphagnum moss. Each cross was planted in a bedding plant tray. These trays were covered with glass or plastic until sprouting started, then a little air was allowed to get to the seeds. The glass was completely removed as soon as germination was complete. These small plants were pricked out when they were about one inch tall. They were then planted in 3½ x 20 inch wooden flats, 54 to a flat, 6 rows, 9 in each row. Medium used in these flats was 70% fine-ground bark, 10% sand, 10% pumice and 10% peat moss. In the flats they were fertilized with one-half strength "Miracid" twice. They grew from 3" to 6" tall in these flats by September 15th. They were then potted in 6½" x 5" plastic pots. The soil used was the same as soil in the flats. The pots were kept in a 50°F. heated greenhouse all winter under lights that came on to lengthen the daylight approximately three hours. One slightly heaping teaspoon of bone meal was added to each pot, mixed with the soil before the plants were potted. This is for budset in the future. Growth of the plants during the winter was very minimal. They seemed to be somewhat dormant and were 4" to 6" tall.

Having read the article in the A.R.S. Bulletin, Vol. 33, Spring, 1979 on Alfalfa feeding and having seen the results Dr. Keith Rodaway had using same, I decided to try it. I used tablets, five to a gallon of water, soaked overnight, and used it the following day. I fed this at the quantity of 1½ cup per pot per feeding. The dates these 100 pots were fed were as follows:

  1. 1-30-83 - one-half cup water per 6½" pot
  2. 2-7-83 - one-half cup water per 6½" pot
  3. 2-14-83 - one-half cup water per 6½" pot
  4. 2-22-83 - one-half cup water per 6½" pot
  5. 3-5-83 - one-half cup water per 6½" pot

These pots were grown in the heated greenhouse until May. They were then transferred to an unheated greenhouse, where they are still growing. The results were fantastic. They grew from 4" to 6" tall by 1-30-83, to as tall as 16" tall by 10-13-83. They branched well, with some stems one-half inch in diameter. The only other fertilizer added was one-half teaspoon of 14-14-14 Osmocote per pot on 3-15-83.

All were repotted in 3 gallon, short pots by 11-1-83. In 1984 they were fed Alfalfa water twice at one cup per pot on 2-26-83 and 3-10-84. This water was made by using 1½ cups of Alfalfa cattle feed pellets per 5 gallons water. They also were fertilized with one level tablespoon of 14-14-14 Osmocote.

The crosses used in this program were as follows:

  1. ( R. yakushimanum x Lemon Custard) #1 x Pacific Gold
  2. Orange Marmalade x Lem's Cameo
  3. Orange Marmalade x Loderi Pink Diamond

As Orange Marmalade is R. yakushimanum x Mrs. Lamont Copeland, they all have "Yak" blood. This makes their growth even more fantastic. They are from 17" to 27" tall and the bud set for their age is remarkable. The #2 cross had 28 out of 30 with bloom buds by October 1, 1984, and they won't be three years old until February 1985. The #1 cross has approximately 50% bud set. The #3 cross does not have as many buds, but their Loderi blood could account for that.

If we hybridizers can get blooms in three years, we could shorten the time involved in producing new varieties.