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On the edibility of fiddleheads

Are Bracken fern fiddleheads edible? The very old Euell Gibbons edible plant books say it’s o.k. but I’ve heard rumors that it is toxic and shouldn’t be eaten. Do the edible Ostrich Ferns grow in western Washington? I have lots of sword ferns, but nobody seems to mention if they are edible.


The fern whose fiddleheads are most commonly (and perhaps most safely) consumed is the ostrich fern, Matteuccia struthiopteris. According to Sue Olsen’s Encyclopedia of Garden Ferns, this plant will grow “in the severe and forbidding climates of Newfoundland and Alaska,” but they do not do well in areas with hot summers. We do occasionally have hot summers in Washington State, so that could pose a challenge, but if you suite the plant in an area with some shade, it might survive a heat wave.

The University of Maine Extension has a factsheet entitled “Facts on Fiddleheads” which mentions the health risks associated with their consumption, and offers tips on how to avoid illness. Note also, this Centers for Disease Control and Prevention page on Ostrich Fern Poisoning.

An article in Fine Gardening discusses which fern fiddleheads are safe to eat.
“Throughout the world, several types of fiddleheads are eaten, though most contain toxic compounds. The most commonly eaten and most esteemed fiddlehead is that of the ostrich fern (Matteuccia struthiopteris, USDA Hardiness Zones 2-8), often simply called fiddlehead fern. The ostrich fern is the safest fern to eat, even though it, too, can contain toxins. The fiddleheads of cinnamon fern (Osmunda cinnamomea), lady fern (Athyrium filix-femina), and bracken fern (Pteridium aquilinum) can also be eaten, but all are at least mildly toxic and can cause nausea, dizziness, and headache, so it’s probably best to avoid them. The safest way to eat fiddleheads is to stick to ostrich ferns and to eat them in small quantities.”

Below is information specifically about bracken fern, Pteridium aquilinum.

Handbook of Poisonous and Injurious Plants by Lewis Nelson et al. (New York Botanical Garden, 2007) says that all parts of the plant are toxic. The toxin is thought to be ptaquiloside, a sesquiterpene.

From the Earl J. S. Rook website (no longer available online):
“Most commonly used today as a food for humans. The newly emerging croziers or fiddleheads are picked in spring and may be consumed fresh or preserved by salting, pickling, or sun drying. Both fronds and rhizomes have been used in brewing beer, and rhizome starch has been used as a substitute for arrowroot. Bread can be made out of dried and powered rhizomes alone or with other flour. American Indians cooked the rhizomes, then peeled and ate them or pounded the starchy fiber into flour. In Japan starch from the rhizomes is used to make confections. Bracken fern is grown commercially for use as a food and herbal remedy in Canada, the United States, Siberia, China, Japan, and Brazil and is often listed as an edible wild plant. Powdered rhizome has been considered particularly effective against parasitic worms. American Indians ate raw rhizomes as a remedy for bronchitis.
Bracken fern has been found to be mutagenic and carcinogenic in rats and mice, usually causing stomach or intestinal cancer. It is implicated in some leukemias, bladder cancer, and cancer of the esophagus and stomach in humans. All parts of the plant, including the spores, are carcinogenic, and face masks are recommended for people working in dense bracken. The toxins in bracken fern pass into cow’s milk. The growing tips of the fronds are more carcinogenic than the stalks. If young fronds are boiled under alkaline conditions, they will be safer to eat and less bitter.”

The book Ecosystems and Human Health by Richard Philp (CRC Press, 2001) states that “considerable evidence exists that bracken fern produces bladder cancer in cattle that eat excessive amounts when better fodder is unavailable, and in rats fed large amounts of it. Because the young shoots, called fiddleheads because of their curled shape, are eaten as a delicacy in many parts of the world, including Canada and Japan, there has been concern over potential for carcinogenic effects in humans. At one point, it was suggested that the relatively high incidence of bladder cancer in Japan might be related to consumption of bracken fern. Epidemiological studies, however, have failed to demonstrate such an association, and it is now felt that eating fiddleheads does not constitute a risk factor for cancer.”

This Northwest gardener, Paghat, also discusses the toxicity and edibility of bracken fern:


“While causality for human illness from eating bracken is not proven, plausibility is present. Toxins break down in cooking, but the traditional light frying or quick parboiling is insufficient to break down potentially harmful chemical components. Bracken should be cooked at high temperatures to be safe, and are quite easy to prepare correctly in woks.

It is not recommended to eat rare bracken under any circumstances because of the statistical increase in cancers in countries where brackens are a consumed in high numbers. Ostrich Ferns are of such low toxicity as to be far preferable to meet the dietary interest in fiddleheads. But as a well-cooked food item eaten only occasionally, there is no indication of risk from bracken. Plausible risk is restricted to the accumulative effects over time from consumptions of high amounts of bracken parboiled or so briefly cooked as to still contain toxins.”

Sword fern (Polystichum munitum) growing in the wild is seldom browsed by herbivorous animals because the rough foliage is fairly repellent. That specific epithet ‘munitum’ in the scientific name means ‘armed.’ You may have seen information about Native Americans roasting the rhizomes and eating them, but this was a famine food resorted to when other resources were scarce. (The leaves were used to line fire pits for cooking, according to Frank Tozer’s book, The Uses of Wild Plants, 2007). I would not take unnecessary risks experimenting with plants that are not typically considered edible.

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lifespan of sword ferns

What is the lifespan of our native sword fern?

The native sword fern, Polystichum munitum, is discussed in local author Sue Olsen’s Encyclopedia of Garden Ferns (Timber Press, 2007). She does not mention the plant’s lifespan except to say that it will suffer and decline with excessive summer heat and humidity (more common in eastern and southern U.S.), and sometimes with long periods of freezing temperatures as well.

Sword fern has a reputation as a tough, long-lived perennial (i.e., returning year after year), and it readily self-propagates from spores, but I have not found any resources which mention the average duration of an individual plant. Most will survive in the Pacific Northwest for many years.

shade tolerant and low maintenance groundcovers

What is a good way to deal with a gravelly area with a lot of shade? Are there good groundcovers that would be low maintenance? Can the plants grow right in the gravel, or do I need to do something to the soil?

If it’s pure gravel, you can just make a border (with rocks and/or wood, preferably non-treated) and fill it with 9-12″ of soil. (No need to remove the gravel.) You buy soil by the cubic yard, so to figure out how much, multiply the length (feet) x width (feet) x depth (.75 or 1), then divide by 27 to get the number of yards. One yard of soil is 3′ x 3′ x 3′, or 27 cubic feet. My guess is that you need less than a yard, but it settles.

You can save money by buying the soil in bulk. Otherwise, you have to buy it by the bag, and they might come in cubic feet. If there is only some gravel, you may be able to get by with the soil/gravel mix that you have. See how much hardpan there is by digging around a little.

If you have lots of weeds in the gravelly area, try mulching the whole area with a thick layer of wood chips (freely available from arborists) Smothering weeds depends upon complete darkness more than anything.

Once you’ve done that, you can plant right away. Here are some plant suggestions. I’ve
included links to pictures, but you can always find more on Google images or
the Missouri Botanical Garden’s PlantFinder.

  1. Lobularia maritima, known as sweet alyssum: You can plant seeds of this and it will come up this year. It’s best to mix it with something else, since it dies down in winter (but self-seeds vigorously and will return). The white seeds the fastest (year to year), but it’s nice to mix with purple. Both varieties smell good and attract
    beneficial insects.
  2. Fragaria x ananassa ‘Pink Panda’: A strawberry-potentilla hybrid that grows fast and spreads easily, is good weed suppresser, and blooms twice a year with pink flowers. This is an excellent groundcover, will probably be evergreen.
  3. Pachysandra: This plant is evergreen, and though it is not as fast growing as some groundcovers, it does spread.
  4. Hardy Geranium spp.: Geranium x oxonianum ‘Claridge Druce’ is a variety that spreads well. Another good variety is Geranium endressii ‘Wargrave’s Pink’; in particular, it seeds itself well. Geranium macrorrhizum has many cultivars, a pleasant scent, and self-seeds readily.
  5. Galium odoratum: Also called sweet woodruff, this plant is prettily scented, probably evergreen here, and spreads fairly rapidly. It produces white flowers in early spring, and it would be particularly good to mix with something taller, like Geranium species.
  6. Oxalis oregana: This native plant looks like a shamrock, and though it is slow to establish, once it has it’s very
    tough and spreads. If you don’t get the native Oxalis oregana be careful, as the other species are very aggressive.
  7. Euonymus spp.: These woody groundcover plants are evergreen, and come in lots of varieties like
    E. fortunei ‘Emerald ‘n’Gold’ and ‘Emerald Gaiety’. Do be sure to get a groundcover and not a shrub version of the plant. ‘Emerald and Gold’ is the most robust choice.
  8. Convallaria majalis: Also known as lily of the valley, this is a vigorous (aggressive!) groundcover.
  9. Maianthemum dilatatum: Called false lily of the valley, this native plant is a good choice for shade groundcover.
  10. Polystichum munitum: The native swordfern (or another fern species) might work. P. munitum is basically evergreen, though you might need to cut out some dead fronds in late winter, and makes a good mix with something else. Other deciduous ferns are higher maintenance.

There are also a couple of plants to avoid!

  1. DON’T plant Aegopodium podagraria ‘Variegatum’: Commonly called bishop’s weed, and frequently used as a groundcover, this plant is very invasive.
  2. DON’T plant Lamium galeobdolon (formerly known as Lamiastrum), either: Yellow archangel is very invasive in Pacific Northwest forests.

pruning and maintaining sword ferns

We leave for about 5 months in the winter and by the time we
get back our sword ferns have sprouted and it’s hard to prune the old
fronds out without cutting off the new ones. These ferns are in a fairly
protected area, so I was wondering if it would be okay to cut off the old
fronds in October before we leave? Also would it help if we just cut the
old fronds and lay them over the plant to help protect it over the


There are some slight differences of opinion on cutting back sword ferns.
It might be fine to cut the old fronds this fall and leave them as
protection over the winter, but it isn’t really necessary to cut them
back until early spring, if at all. The local web site for Great Plant
recommends cutting sword ferns to the ground in late winter, or
only cutting back every 3 years or so on plants growing in poor soil:

Paghat’s Garden, another local gardening site recommends only cutting away dead fronds. Excerpt:

It was once believed it was necessary to cut all the fronds off in
February immediately before new growth begins, but it is now the
recommendation to only trim dead fronds. By April when the fiddleheads
are thickly erupting, any of last year’s fronds that have lost their
beauty should be removed, but only for looks’ sake, removing up to as
many as all of them. They’ll soon enough be replaced by new. Just don’t
remove the fronds before winter’s final frosts, as the reason this fern
adapted itself to keeping its fronds green at least until winters’ end is
to shelter & protect the humping crown from excessive cold or from
sunlight in winter when deciduous trees might not adequately shade the

Since your plants are in a protected area, you might be able to go ahead
with your October trimming, but really the main reason to trim is an
aesthetic one, so it isn’t absolutely necessary.

planting to stabilize a steep slope

Can I plant groundcovers, shrubs, and trees to stabilize a steep slope?


There are several resources which will help you in
selecting plants to prevent erosion and mudslides on
your slope.

Please note that these articles are merely suggestions and should not be construed as advice. We are librarians, not engineers!

None of our standard books on trees mentions the soil binding quality of tree roots. However, the Miller Library does have very good technical books and articles on slope stabilization. (For example, Slope Stabilization and Erosion Control: A Bioengineering Approach, edited by R.P.C. Morgan and R.J. Rickson, 1995.)

I do want to note one thing that many articles mention: no amount of established vegetation will hold a steep slope if other forces are present that would contribute to a landslide.

The Department of Ecology website has a list of appropriate plants.

Additionally, there are a number of books with
information on the subject. Vegetative Contribution
to Slope Stability at Magnolia Park
(by Kathy Parker, 1996)
recommends Oregon grape (Mahonia), which she suggests
for gentle slopes.

Other smaller plants she lists are:
Polystichum munitum (native sword fern)
Vaccinium ovatum (evergreen huckleberry)
Symphoricarpos albus (snowberry)

Larger shrubs in her list:
Alnus rubra (red alder)
Philadelphus lewisii (mock orange)
Sambucus racemosa (red elderberry)

Small trees:
Acer circinatum (vine maple)
Amelanchier alnifolia (serviceberry)
Corylus cornuta (hazelnut)

For steeper slopes, Parker says that they may not be
good candidates for vegetative rehabilitation unless
you put in some kind of structure. She says that Jute mats can be used in conjunction with native seed, mulch, and shrubs, if carefully anchored. She also mentions a Weyerhaeuser product called Soil

Steep Slope Stabilization Using Woody Vegetation (by
Leslie Hennelly, 1994) has a plant list, as well as a chart which indicates plants used to control erosion, the degree
of the slopes, and the rate of success in resisting

Two titles which focus more on the garden design
aspect of planting on a slope are
Hillside Gardening : Evaluating the Site, Designing
Views, Planting Slopes
(by William Lake Douglas, 1987) and
Hillside Landscaping (by Susan Lang and the editors
of Sunset Books, 2002).

Garden Tip #102

To create a desert oasis look plant a few hardy palms and then add evergreen hardy ferns such as Deer fern (Blechnum spicant),Big leaf holly fern (Cyrtomium macrophyllum), Western Sword fern (Polystichum munitum), and Soft shield fern (Polystichum setiferum). Growing a few ferns usually leads to growing many ferns – there are so many cool species out there. Learn more about the world of pteridology (study of ferns) by joining the locally based Hardy Fern Society. Members receive a packet of fern growing information and a quarterly newsletter; they also participate in a spore exchange and produce the wonderful Fern Festival and plant sale each June. To join the society send $25.00 to The Hardy Fern Foundation, P. O. Box 3797
Federal Way, WA 98063-3797.