San Diego Fern Society

August 2018

August Fern Society

The San Diego Fern Society meets at 7:30pm, Thursday August 16, Casa del Prado Room 101, Balboa Park. This month is the Fern Show, so the program will be brief. Kathy Thomson will demonstrate a novel technique, growing a Maidenhair Fern in a container with a mop. This unique idea was presented in the Fiddlehead Forum of the American Fern Society by Albert Sng Chay Jian of Singapore.

Come prepared to sign up on the schedule of responsibilities for the Fern Show and Sale. If everyone helps, the tasks are shared and not overwhelming to just a few volunteers. There are tasks for all abilities, with or without fern experience. For example, it is important to have room hosts at all times, greeting guests and just watching over the Show.

After the Thursday meeting, various members will assist with identification of plants. For those who are not sure of the name of their fern, please bring the plant in Thursday, including a couple of old fronds with spores on them. Assistance with final trimming will also be available.

Plant registration forms may be prepared on either Thursday or Friday.

It is important to ensure that potential Fern Show plants are free of pests and disease. While cleaning up the ferns, grower must check for evidence of disease. No plants will be allowed in the Show room with ants or bugs, and all damaged fronds must be removed.

Plants From the 2017 Fern Show:

1Microsorum scolopendrium 'green wave' copy
Above: Microsorum scolopendrium 'Green Wave'. Below: An Elaphoglossum from Ecuador. Photos credit: K. Russell.
Elaphoglossum sp Ecuador1

August 18-19
Saturday noon to 5pm
Sunday 10am to 4pm
San Diego Fern Society
Show & Sale
Casa del Prado Room 101
Balboa Park, San Diego CA

Report on July meeting

Using photos and input from members, the July program focused on the natural habitats of ferns. Even though popular thinking is that ferns need plenty of water and forest shade, many ferns grow and thrive in more adverse conditions. Photos showed ferns which are green even though growing in snowy areas or at quite high elevations and exposed locations. Ferns grow in deserts and also dry tropical forests. And certainly, ferns grow in beautiful moist areas such as Tasmania.

Members and friends brought a great selection of fern rhizome/root cuttings to share.


The annual membership fee is $12 for a single or household membership, through December 2019. Provide name, mailing address and email at a meeting or mail to the address on page 6.

The coming August Show and Sale is a great time to gain new members. Current members can encourage those with fern interests to join the Fern Society. When guests ask what ferns to grow, the list on page 5 is a guide.

A peruvianum Cathy copy1
A tropical Adiantum peruvianum grown by Cathy Faigle was shown at the 2017 Fern Show. Note the larger sized pinules. Photo credit: K. Russell.

Selling Your Own Plants at the Fern Sale

Members may sell their own ferns and specialty plants at the Sale, following policies of the Fern Society and San Diego Botanical Garden Foundation. Sellers need to inform a board member in advance and also assist with the Show and Sale.
Fern Show Rules

1. Entry of plants should be completed by 4pm on Friday, with plants ready for display (groomed and neat). Plants may be brought Thursday evening, or Friday from 2pm to 4pm. Exhibitor will prepare entry form with plant names.
2. Judging will take place on Saturday, 8:30am until noon. The Show room will open to the public around noon, or earlier if ready. All displays must remain until 4pm on Sunday.
3. Plant owners must take their plants out of the room after the 4pm close on Sunday, or make arrangements.
4. The Show is open to entries by the general public. An exhibitor may enter any number of plants, and any number in the same class.
5. Plants may be entered for competition or for display only. All plants entered for competition must have been owned and grown by the competitor for at least 90 days prior to the Show.
6. Plants must be groomed and containers must be tidy. Only clean, disease and pest-free plants will be accepted into the Show room. A plant with any sign of disease or infestation will be immediately removed.
7. Use of leaf polish is not permitted.
8. Previous winners: Best Fern of Show (non-Platycerium) and Best Platycerium of Show plants may not be entered for competition. (They may be entered for display). No individual plant may win Most Unusual Plant award more than once.

Aspleniums for many habitat types

There are some 650 species of Asplenium ferns, with great variety. Asplenium trichomanes shown in the July Fern Society program is small, dark green, very cold tolerant, and green all year.

Asplenium scolopendrium, better known as Phyllitis scolopendrium, may grow one to two feet tall and also is evergreen and hardy to cold. British fernists have numerous cultivars, with crested, crisped frond edges.

P scollie detail copy 21
Asplenium scolopendrium, also known as Phyllitis scolopendrium, was displayed at the 2017 San Diego County Fair. Plants are sometimes available at local nurseries.

In tropical and subtropical areas, some Asplenium species develop fronds more than three feet long. The bird's-nest types are found growing in trees, with Asplenium australasicum commonly used by local fern growers. Native to Australia and islands, this plant is not as cold-sensitive as A. nidus.

1Asp 'silver wings' Philippines calllard copy
An Asplenium cultivar called 'Silver Wings' grown by Don Callard is a variety from Philippines. Note the small container for this very large fern.

Some Aspleniums are referred to as Mother Ferns, and form buds on the frond, which may be grown up in to new plants. The type commonly in cultivation was formerly listed as Asplenium bulbiferum, but is now better identified as a hybrid, Asplenium X lucrosum. Growers and plant labels may still be using the older incorrect name. The plants are attractive and relatively easy to grow, and hobbyist fern growers in a variety of climates from cooler to subtropical enjoy them.

Mother zoo1
This Mother Fern Asplenium X lucrosum is growing at the San
Diego Zoo near the hippos. Photos this page credit: K. Russell.

Chris Goudey found a naturally occurring hybrid from an Australian island which he cultivated, calling it 'Austral Gem.' This popular fern is easily found in plant nurseries and grows outdoors in mild climates, remaining green. Chris Goudey determined it to be A. difforme X A. dimorphum. He has found hybrids in nature and additionally crossed Aspleniums from New Zealand and Australia to develop others. This is the same Australian fernist who discovered the Asplenium goudeyi growing on Lord Howe Island, as shown at the July Fern Society meeting.

A 'Austral Gem' copy1
Asplenium 'Austral Gem' was displayed at the 2018 San Diego County Fair, Fern Society exhibit. This is the natural hybrid A. difforme X A. dimorphum. Plants are frequently available at local nurseries and home stores. They may not have accurate name labels. Plants should be kept moist but not overly wet. Partial sun or bright shade areas are appropriate for 'Austral Gem.'

Aspleniums fair 20181
Aspleniums of the Bird's-nest varieties were planted into garden beds at the Fern Society exhibit of the 2018 San Diego County Fair. Shown are Asplenium australasicum and Asplenium goudeyi. Photos this page credit: K. Russell.

rock planter 20101
An Asplenium is here growing in a rock planter, exhibited at the San Diego Fern Show in 2010. The Bird's-nest types of Aspleniums generally grow in trees. However some grow naturally in rock, especially Asplenium goudeyi.

At the Fern Show August 18-19, look for Aspleniums in the Sales area and then recommend them to the Show guests. Remember that sales are in cash.

1. Acock, P. (2018). Lord Howe Island. Fiddlehead forum 45, 21-25.
2. Hoshizaki, B. & Moran, R. (2001). Fern grower's manual. Portland, OR: Timber Press.
3. Steffen, R. & Olsen, S. (2015). The plant lover's guide to ferns. Portland, OR: Timber Press.

In my work with cultivated ferns, I am always relieved when people come up to me and say, "I really am not interested in the name, it is the fern I enjoy!" That really takes me off the hook, so to speak, because I probably can't remember the name of the fern anyway, but I can always enjoy the fern along with you.

Barbara Joe Hoshizaki

Hoshizaki, B. (1973). Ferns for Subtropical Gardens. Fairchild Tropical Garden Bulletin.

Suggested ferns for the San Diego area:

Adiantum raddianum, Adiantum hispidulum (Maidenhair Ferns). Adiantum raddianum has many cultivars, and grows well near a concrete wall or patio. Both of these ferns die back briefly in winter, and old fronds can be removed to keep the plant attractive. Adiantum hispidulum produces bright pink fronds in early spring, which soon turn green. The maidenhair ferns do not appreciate complete dryness, but with watering may come back.
Nephrolepis exaltata (Boston Fern). There are many newer cultivars which provide variety to a fern collection. Some have frilly fronds; some are small (such as 'Compacta') to fit your space requirements. They grow well indoors when given good light, and outside in patios. Nephrolepis cordifolia (Sword Fern). Similar to Boston Ferns, these plants with more upright fronds are well suited to San Diego gardens. Varieties such as 'Lemon Buttons' combine well in garden beds with other plantings. Water needs are very modest and plants grow in part sun to open shade.
Cyrtomium falcatum (Holly Fern). This fern grows readily in garden beds or placed in a rock wall. Plants are tolerant of low water and some sun. A dwarf variety is popular.
Davallia trichomanoides (also called Humata), Davallia mariesii, Davallia tyermanii (some of the common names used are Rabbit's or Squirrel's-foot Fern). The rhizomes will grow over a moss-lined basket so you can see the fuzzy "rabbit feet". Provide regular water to keep basket from drying out. These can also be grown in the garden over rocks.
Blechnum gibbum (Silver Lady). This fern may show interesting pink fiddleheads in spring. Over time, the plant develops a small trunk and will be a tree fern. It may be kept in a container but will make a lovely landscape plant as it seems to have attractive fronds throughout the year.
Pteris albo-lineata. Plants work well in containers but also in the ground. This fern will go nearly dormant in winter. It produces two types of fronds, sterile and fertile. It needs water in summer.
Pellea rotundifolia. Provide good drainage and water just before soil is dry. Plants flourish indoors with good light, or outside.
Phlebodium pseudoaureum, Phlebodium aureum. A favorite large basket fern, it also can be grown in garden beds where there is room for plants to spread. Frond color varies from bluish green to green hues, depending on variety and light conditions. Although tropical in appearance, these ferns seem to be well adapted to the San Diego area climate.
Platycerium bifurcatum (Staghorn Fern). These are mounted on boards with sphagnum moss, and hung in partial shade. Water should be put into the moss behind the plant, and must drain. There are many hybrids and cultivars which need just basic plant care and modest water, and should provide many years of growing pleasure.

Unusual plants, hiding in the garden

maris copy1
Adiantum X mairisii is a hybrid maidenhair which was propagated in recent times for the US nursery trade by Casa Flora growers. Plants are distinct from Adiantum raddianum, the Maidenhair Fern commonly grown in our area. One of the hybrid parents is Adiantum capillis-veneris which is found throughout the warm temperate and subtropical areas of the world including California. The other parent is undetermined. This hybrid has been in existence for well over 100 years in England, coming from the nursery of Mairis and Company. Fronds may extend up to 15 inches, lasting into the fall but generally not over winter. Photo credit: K. Russell.

The Year of the Garden

Pyrrosia polydactyla is a fern with palmate fronds. Native to Taiwan, it should be considered semi-tender to cold but is suitable for the climate of Southern California. Plants may be grown in the ground or in containers. Walt Meier and others in the Society have successfully grown this fern.

pyrrosia polydactyla copy1
Pyrrosia polydactyla on display at the San Diego County Fair, Fern Society 2018 exhibit. Photo credit:
K. Russell.

San Diego Fern Society Officers

President Kathy Thomson
1st Vice President Paula Couterier
2nd Vice President Bart Keeran

Secretary Kathie Russell

Treasurer OPEN

Board Members:
Bruce Barry
Bob Charlton
Richard Lujan

Past President Don Callard

Webmaster: Bob Charlton

Fern Society email

Bring $12 cash or check (payable to San Diego Fern Society) to a meeting or mail to:

San Diego Fern Society
4780 Glen
La Mesa CA 91941

The San Diego Fern Society was established in 1976 to provide a source of information on ferns; to arrange for people to study ferns together; to encourage the use and enjoyment of ferns in gardens, patios, and the home.

The Society aims to encourage all horticultural activities by example, education, and exhibits; to interest people in the beauty and satisfaction to be found in garden, patio and home living; to promote and stimulate interest in ferns; to encourage and develop culture of various types and varieties of ferns; to provide for the exchange and dissemination among Society members of information relating to culture of ferns.

Volume XXXXII, Number 8