2010 Theodore Klein Plant Award Winner

Dryopteris x australis – Dixie Wood Fern is a Theodore Klein Plant Award winner for 2010. It was selected because of its outstanding upright 3-4+ foot tall foliage that is considered tough and adaptable by those that grow it in Kentucky. Fern Curator at Whitehall, Louisville Historic Home, Ralph Archer said of Dixie Wood Fern: Most authors list this fern as 4-5 feet tall. The ferns at Whitehall in dry shade (under a large elm tree) are normally slightly over four feet after a reasonably wet year but shorter if the previous year was dry. A group of ferns planted two to three years ago in morning sun were almost five feet this year. In addition to sunlight and ample rain, they benefitted from biweekly, significant water overflow from an adjacent fern bog (built in 2007) as well. It is a naturally-occurring hybrid between D. celsa (log fern) and D. ludoviciana (southern wood fern) that is found in native groups from Virginia to Louisiana. It has been observed as a dieback plant in zone 5, but is semi-evergreen south of that area. Ralph Archer commented on how he manages Fronds with: I prefer to leave the fronds until they turn totally brown. There is speculation (but no scientific studies to my knowledge) that evergreen ferns pull back food supplies from green fronds when starting growth. Usually I do not cut the fronds off in the woodland garden at all as they also provide good mulch. This fern has a strong tendency to drop its fronds flat on the ground after the first heavy frost or hard freeze. Some think this is unsightly, but they provide wonderful winter cover for both the fern crown as well as perennial plants nearby . The lack of spore production limits propagation to division and the tendency of wood ferns to naturalize a garden. Typical of many perennials this can be done in late summer-early autumn or early spring. While tolerant of dry conditions and full sun and considered a plant for the difficult dry shade climate under trees it does better in part to full shade with adequate moisture availability. Ralph Archer comments that: D. x australis as well as both its parents are listed as wetland plants. Based on my experience, I would not suggest planting this fern (or its parents) in difficult dry conditions and full sun. My experience has been that these plants do not do well in difficult dry shade such as among large maples or in strong afternoon sun. I planted several D. x australis in significant afternoon sun in my first fern garden. In spite of regular water, none survived. The growth size of the D. x australis planted in dry shade and those with ample water from the bog and morning sun illustrate the stress from dry conditions. As a general rule it seems that a significant lack of moisture from either root competition or sun exposure is a limiting factor for this fern. There seems to be a limit to the amount of afternoon sun that is tolerated before causing plant foliage burning. A spectacular addition to any garden but very useful in the woodland garden.

Ronald L. Jones’ Plant Life in Kentucky reports that both parents of the hybrid Dixie Wood Fern are found in Kentucky making the possibility that the hybrid might be found here also.

A special thanks to Ralph Archer for his important comments to get the most enjoyment from this wonderful native fern.