Dr. Bob Gilbert – Columnist
Over time I have tended to discover plants that have become favorites, mostly trees. Perhaps this has happened because of an unusual blooming pattern, or a personal history with a plant that brings back memories or appealing distinctive bark, leaf color or even the circumstances of a plants acquisition. My favorite tree at Smith Gilbert Gardens remains Parsley Leaf Hawthorn, CrataeguS (kTa-te-gus) marshalii. We obtained the tree from a Florida native tree nursery in 1987. I like everything about this tree but its leaves and its bark are the stand-out features for me.
Hawthorns are difficult to identify down to the species level because they tend to cross pollinate with other Hawthorn species producing offsprings with characteristics of both parents. Haw means hedge or fence but a haw also refers to a berry or fruit. Hawthorns can make excellent natural hedges because of their dense growth and sharp thorns. Crataegus is derived from a Greek word kratos meaning strength referring to the strength of its wood and thorns. This plant was first described by Humphrey Marshall in 1785 and was named in honor of him.
The exception to Hawthorn identification difficulties is Marshalii because its leaves are deeply cut and resemble Italian Parsley. No other native hawthorn has this leaf pattern. Also, it has distinctive scaly exfoliating bark that exposes greens, browns, tans and orange layers which helps with winter tree identification.
This native tree has a wide distribution range in the southeast. It can be found in WNC. It is not often noticed as it is an understory tree. It likes high shade and moist soil. It can grow up to 20 feet. It produces beautiful white apple-like blooms in May that develop into small red berries – haws. These are not favored by many birds so the fruits persist. The haws are edible and make interesting jelly so I have read. The seeds have small amounts of cyanide thus the seeds should be discarded. Dried Hawthorn leaves are used to make tea. There is a Mexican Hawthorn species called Tejocote. Its prepared roots can be found in health food stores. It has an amazing range of properties and medical uses. In the South, numerous Hawthorns species are called Mayhaws that are used for conserves and fermented for wine.
I found only two minor faults with Parsley Leaf. It produces slender upright stems from its underground roots. This habit is referred to as stoloniferous. I think these growths distract from the tree’s beauty. They are usually pruned off but in a hedge they could be an advantage. It also produces water shoots on the branches which also distracts. It is rather slow growing accounting for its strong wood. Fast growing trees produce weak or soft wood. Its beautiful bark does not start peeling until the tree approaches maturity. You have to be careful when pruning it as its thorns are sharp.
On rare occasions while in bloom it can become a victim of Fire-blight. This is a bacterial disease is transmitted by insects when the tree blooms are soaked. I have not seen this here. They are also susceptible to a Cedar-hawthorn rust.
There is in Europe a tree/shrub called Medlar. It is related to Hawthorns. It produces a strange looking fruit that has to blet or begin to rot before it is edible. It often served with port wine. It is not found naturally in the U.S. except in a small corner of Arkansas where some Czechoslovak immigrants brought some plants with them from home. Medlar fruit does not look appealing. You can find plants for sale in mail order catalogs. I am not sure I would want to risk a good bottle of port to serve with them. What other fruit do we blet before serving it?
We planted three Parsley Leaf Hawthorns in a bend in our driveway. To hide the transformer box and well housing a hedge of Ilex glabra, Inkberry Holly variety ‘Shamrock’ was planted. Then to break up the monotony of the dark green hedge we planted Chamaecyparis pisiferae Japanese Falsecypress variety ‘Gold Mop’ to create a tapestry effect. In the bend of the hedge three Parsley Leaf Hawthorns were planted in about 2009. Note, there is confusion about “Gold Mop” and “Gold Thread” Chamaecyparis. “Gold Mop” is supposed to be shorter but they are often mislabeled and are hard to distinguish.
I find Crataegus marshalii in local nurseries on occasions. Ours are not quite old enough to display the multicolored bark. We were thrilled when we happened upon these trees in a WNC nursery. They are still casting their spells here and in Kennesaw.
A great scholarly reference hawthorn guide is HAWS a Guide to Hawthorns by Ron Lance a WNC biologist.
Dr. Bob Gilbert co-founder of Smith Gilbert Garden in Kennesaw,Ga.
Karen Lawrence professional horticultural and wildlife photographer from Franklin.