‘Chance’ seedlings produce variations on a theme

White Mulberry

Dr. Bob Gilbert – Columnist

Dr. Bob Gilbert

Years ago, a wonderful lady I will never forget came to my office for treatment.  Alice was a substitute teacher who just barely reached five feet on her tiptoes.  During an office visit she told me a story with a big smile on her face and a twinkle in her eye.  She was in a new classroom and a young kid came up and pulled on her sleeve and said “say, what do they call you, is you a midget or is you a dwarf?  She was prepared having been asked this before and happily explained the difference between the two.

Several years ago, while visiting a new garden and I noticed a holly growing very low to the ground.  It looked like something had fallen on it and it could never get up again, a fallen plant. Sometimes you find trees and shrubs flattened by an adjacent tree fall.  If they have enough roots still intact, they eventually will send up vertical shoots reaching for the sun. There was nothing vertical about this plant. Its label read Ilex opaca “Maryland Dwarf.”  It is commercially available.  If I had discovered it, I would have named it Ilex opaca “Alice.” This is often how plants get their names, not always based on scientific observations but sometimes for sentimental reasons.

Ilex is the Latin name for the genus Holly and is pronounced EYE-leks. Opaca means dull, opaque or not shiny, pronounced oh-PAK-uh.  Thus, this scientific name aptly describes a holly with dull leaf surfaces.  Ilex opaca is native here in WNC.  It is dioecious (dio-two) meaning its male and female flowers are on separate plants requiring two different plants to reproduce. The female produces the characteristic holly red berries or fruits. Monoecious means one has both male and female blooms on the same plant. It is very easy to tell a male holly bloom from a female.  In the privacy of your own home take a look.  Only the female holly bloom has it in its center a small pale swelling the ovary that will ripen unto a berry.

Maryland Dwarf Holly

Maryland Dwarf grows 3-4 feet tall but spreads out and becomes quite wide.  It makes a great ground cover and could work well for erosion control except it is not a fast grower.  One other horizontal spreading American Holly “Clarendon” gets 6-8 feet in height and grows as wide.  It is a chance seedling that was first found in Pinehurst, N.C. 

The Ilex opaca holly found here in the woods is commonly called American Holly.  It is evergreen, slow growing but can reach 30 feet. It is dioicous.  The foliage is dense enough for small birds to roost in over night.  It would be difficult for a predator such as a hawk or an owl to fly into a holly tree looking for a meal. 

Occasional variations can be found in plant seedlings. In fact, this is often how new plant introductions are found.   For example, there is an American Holly with bright yellow berries called “Canary” that was discovered here in WNC.  It sometimes can be found for sale at specialty nurseries. These are called “chance” seedlings; purely by chance a variation occurred. Maryland Dwarf is a chance seedling. A Pennsylvania nurseryman Earle Dilatush found it in a group of opaca seedlings growing in Maryland.

Another source for plant variations is on the plant itself.  Every once in a while, a branch will show variation in leaf size, color, growth patterns or berry color.  This branch can be rooted and introduced as a new plant variety, a cultivar, but it has to grow true to form and not revert back to its origin form.

If you harvest the berries from Maryland Dwarf and grow them you will not get the same plant as the parent.  These seedlings will have variations and most will grow into a normal sized upright tree.  The only way to create an exact duplicate of the parent is to root cuttings from an interesting branch.

This particular plant’s horizontal branches are genetically programmed to stay that way.  You could tug, stake, twist and coax Ilex opaca Maryland Dwarf all you want she is not going to grow tall.  One lesson to learn here is when taking cuttings, take specimens from vertical branches if you want a vertical plant, horizontal if you want a more horizontal lower growing plant. I found a white mulberry tree in the woods in Kennesaw that had fallen and one branch survived and grew vertically resulting into a very sculptural plant.  It has become a major feature at Smith Gilbert Gardens.  

A few years ago, I purchased some hollies from a specialty nursery.  One of the plants I acquired never grew tall even after staking its leader upright.  It was listed as an upright tree meaning it was a rooted cutting from an upright tree.  I later learned that most likely the cutting came from a very horizontal branch.

Dr. Bob Gilbert is co-founder of Smith Gilbert Gardens in Kennesaw, Ga. Karen Lawrence is a professional wildlife and horticultural photographer in Franklin, N.C.