Ferns Rule

Boston Fern

Is there anything more tropical than the sweep of a fern bed? In a residential setting, this large group of ancient plants can replace pieces of lawn, cover a shady area below a maturing tree, replace troublesome grass in a side yard, or provide very detailed planting in the dooryard. In larger, institutional settings, these benefits grow in scale, offering lovely tropical appeal, huge variety, affordable prices and very low maintenance. What’s not to like?

 Fanciful History

Ferns are a huge group of flowerless plants in the Class Pteridophyta that appeared in the fossil record some 360 million years ago during the Carboniferous period of Earth’s history, and were among the earliest vascular plants. Like trees and other common plants, ferns have differentiated tissue for water and food transportation, and they have stems, leaves (called fronds) and roots. But unlike the flowering plants, there are no seeds, pollen or fruit: they reproduce by means of small eruptions called ‘sori’ on the back of the fronds. These are usually dark brown, sometimes subtle, usually prominent, and contain spores that are disseminated by wind, or animals, or water. 

Florida has more native ferns than any state other than Hawaii: 123 species, plus more than 20 exotic or hybrid species. By the early 1900s a huge industry in Florida and in northern cities was producing Florida ferns for floral use. In 2002, fern production in Florida alone was an $86 million dollar industry. 

Macho Fern

While we do use a number of different ferns in the landscape industry, our palette is dominated by several species in a single genus called Nephrolepis (nef-ro-LEP-is).

 Endlessly Useful

Ferns are upright, generally low-growing, herbaceous plants that prefer bright light and rich, moist soils (don’t let this dissuade you, though; they do just fine in our sand). All species in this genus are the same light-to-medium green. They are easily massed, creating a medium texture and appealing monoculture quite early, tolerating a wide range of light and water conditions. Use them in dark to bright environments; none will thrive in full summer sun. They are quite xeric once well established. And remember that ferns will not survive prolonged flooding. 

Choose your fern based on your needs for a detailed, up-close fern, or a faraway massing fern; choose also based on needed height, ranging from Macho at four feet or so to the Boston type ferns that are as low as a foot or so.

Wart Fern

Naming these desirable plants is tricky and often just plain wrong. Here’s your guide:

Macho Fern is a 4’ tall critter and is Nephrolepis falcata. The diminutive Boston Fern which is N. Exaltata, and there are several named varieties of this species. The Giant Sword Fern is also N. biserrata. There is a Fishtail Fern, too, with more detail in the frond; this one is also N. falcata.

These plants are all highly recommended and widely available. However, there are also a few non-native and invasive species that are sometimes confused in the trade. Among these is the tuberous Sword Fern, or N. cordifolia, which has become a serious pest and is no longer cultivated.  This fern will have a round, translucent tuber in the roots, easily visible by lifting the plant from the container. Don’t use it.

The University of Florida’s Web site has much more information that helps differentiate these plants (http://edis.ifas.ufl.edu/ag120).

 But what do we care? We just love the lushness of these wonderful plants. Let’s have a look at a few common and not so common examples.

 Using Ferns

Using the ferns couldn’t be easier.  Because they naturally spread, spacing of new plants is a function of

Maidenhair Fern

your patience and your pocketbook. I usually specify one gallon plants 18 to 24 inches apart. The natural growth pattern means that they will gently spread, filling a bed and eliminating the need for maintenance. When they spread too far, simply turn your weed-wacker sideways, running the whips close to the ground, cutting new vertical fronds. Never ‘prune. Over-hanging fronds.

Interested in some of the rarer ferns? Me too! I’ll cover these in the fall.

A version of this piece appeared in the Naples Daily News 9.7.2012.