Our Experience Growing Rhododendrons of the 1990 ARS National Convention

Rhododendron anwheiense
Picture by S & J Perkins

Background

The ARS National Convention hosted by the Massachusetts Chapter in May of 1990 occurred during our first year as members. In fact, our first activity as new members in fall 1989 was potting, at Wyman’s Nursery, of tissue cultured Rhododendrons for the Convention. We recall two memories from that day. First, we were amazed by how hard the volunteers worked. Second, we were surprised by the large variety of plants potted and how few of the varieties we knew. While potting we heard comments about both the 1980 (the last conference hosted by the Massachusetts Chapter) and the upcoming 1990 Convention, but not knowing what such an event involved we really had little or no context for interrupting these utterances. However, one thing became quite apparent the 1990 Convention involved the sale of a large number of Rhododendrons. This single observation was reason enough for us to want to attend the then upcoming Convention.

On our way home from the potting of the Convention tissue cultures, we attempted to recall the names of the Rhododendrons that each of us had planted that day. By the time we arrived home we had compiled a list of 45 or so cultivars. We spent time that winter attempting to learn sometime about each plant on the list in preparation for the spring Convention. When the Convention started, we had our want list ready. By the time the Convention was over we had acquired 60 different Rhododendrons in 4" pots not to mention 10 or so Kalmia. Most of these Rhododendrons were purchased at the plant sale. However, some plants were acquired by helping set up the Convention banquet and others were purchased from P4M (Plants For Members) later that year as "left over" Convention plants. Of the 60 Rhododendrons acquired 27 were tissue cultures and the remaining 33 were rooted cuttings.

We planted the Convention Rhododendrons directly into our yard rather than growing them on in a cold frame as was recommended. Indumented plants were placed on a sandy slope in a semi-sheltered location on the north side of the house. The other Rhododendrons were planted in woodland soil in partial shade. Each year, plants smaller than 12 inches in diameter were protected from winter wind and sun by using reinforced cardboard cylinders.

Observations:

• If a plant survives the first full year it usually survives.
• Evergreen azaleas and lepidotes frequently bloom in the 1st or 2nd season whereas elepidotes and deciduous azaleas typically take 5 or more years to come to bloom.
• Rhododendrons of questionable hardiness often survive but do not thrive.
• Plants seem to grow slower and take longer to bloom in our yard than they do in other members' gardens.

Summary

The following plants were available at the sale but not purchased as "Convention plants" because we had acquired them in previous years. (See below for table explanations.)

For comparison purposes the column marked K groups plants by major categories: d (deciduous azalea), e (elepidote), g (evergreen azalea), and l (lepidote). Within each category under Comment are our personal opinions of ease of growth (G) and desirability (D) from 0-9, (i.e., G:9 D:1 would be a very easy to grow but highly undesirable plant). Since we can only comment on our experience, desirability refers to how attached we are to that particular plant in our yard.

Although the desirability of a plant is based on many factors, a single factor may greatly enhance its overall rating. Examples are indumented foliage (R. rufum), winter foliage color (‘Black Satin’), early bloom (‘April White’), late bloom (‘Parade’ if it ever flowered), spreading habit (R. nakaharae Bovee), dwarf habit (‘Princess Anne’), blooms at a young age (‘Percy Wiseman’), and unusual parentage (‘Blewbury’).

Plants that have flowered any year from 1991-95 have a date represented as a 2 digit number where the first digit indicates the month and the second number the "6 day week" of bloom, (i.e., 51 began flowering from May 1st-6th). Dead is self explanatory for the year of death (greatly lower the score for ease of growth). Culture indicates rooted cutting (R.C.) or tissue culture (T.C.). P4M number is provided for cross reference.

The next table summarizes our experience growing the Convention Rhododendrons. Two additional columns relating to the approximate height and width (in feet) of the plant at the end of the growing season in 1995 are included.

Note that this article first appeared in The Rosebay of the American Rhododendron Society Massachusett Chapter.