Ferns - outdoors and indoors.

Hardy Garden Ferns - Tender Indoor Ferns.

We are grateful to Ian of Newcastle for this informative article. Ian gained a Special Honours Degree in Botany from Sheffield University 1987.. He is a collector of anything Pteridological (Ferny) or Mycological (Fungi)
Married with 3 sons, avid gardener and happiest when out in the fields!.....or when Newcastle United are winning.......something.........anything!

Ferns or Pteridophytes, are amongst the most widely used foliage plants. They are generally all hardy, except for tropical species, which need a cool frost free greenhouse or an indoor site.
Ferns add height to planting schemes and give an architectural form to a border. The right fern in the right spot can make a shaded area light up. Ferns are generally used in area's where other plants will not grow, heavy shade, damp soil, little top soil and even dry shade.

They are not plants that need pampered either, once established a fern will need very little, or no attention. Given the optimum conditions, they will thrive and give a wealth of different form throughout the growing season. There is nothing better than to see the fronds start to uncurl in spring - an indication that the summer garden is well on its way!

Ferns - their cultivation and uses.
Hardy ferns are suitable for most outdoor planting area's. They need not be restricted to shade areas, as long as their roots are in shade and they are kept watered the same as any other border perennials.
Soil types preferred can be (with a few exceptions) anything in the neutral to alkali range. This can be achieved in a number of ways.
The exception are acid loving ferns like the Blechnum sp. and Cryptogramma sp. as well as Thelypteris oreopteris.
Ferns in general prefer a growing medium based on leaf mould compost, if you make your own all the better as this can also be used as a spring mulch around the crowns. If you are potting plants in containers on, or putting plants into the ground a few minutes making them at home will reap rewards in years to come.
An excellent mixture for ferns to be planted into is:.......
3 parts leaf mould, or peat substitute (Peat can be used if nothing else is available, but greener people prefer not to use Peat as it is damaging the environment that it comes from.) 2 parts fine grit or sand and to this add some charcoal half a cup per planting is enough. For those who still burn wood and get charcoal and ash, in their gardens. This can be mixed into compost heaps to add potash and other trace elements. It is particularly useful in leaf compost making. Finally add some general organic slow releasing fertiliser to the mix, blood, hoof and bone or pelleted chicken manure is best. This will slowly release over the year and give the plants a really good start.
The one essential to ferns in order to get the best out of them is rainwater. If you have a water butt in the garden this is preferable to watering from a hose tap. Always use rainwater if it is available.
Many tropical ferns need to be kept in a conservatory, cool greenhouse or in and around the home. Their care is little but the reward is impressive.

Click on the images to see an enlargement.

Dicksonia antarctica
The New Zealand Tree Fern

Polystichum setiferum
divisilobum - Acutilobum

Dryopteris felix-mas

Choose the fern to fit the habitat you want it for. There is a fern for almost every different situation. It is worth hunting out the suppliers on the internet, and ordering by mail order. They will arrive in the ferns dormant season as crown and can be planted out at anytime. It is also worth selecting just the right fern and taking time over your choice.

DRY SHADE/DRY DAPPLED LIGHT
Choose Dryopteris filix~mas (Male fern) if the area of planting is dry, this fern is more tolerant of dryness than any other, but it will thrive in damp area's even more.

DAMP SHADE
Choose any of the following, Matteuccia strutheopteris (Shuttlecock fern), Dryopteris wallachanii (Wallichs wood fern) both are plants with a 'WOW' factor. Other good choices are, Dryopteris erythrosa (Blood red fern) so named as its unfurling spring fronds have a blood red tinge to them.
Athyrium filix~femina (Lady fern) is also very similar to D. filix~mas(Male fern) but is smaller in size and greener in colour the compliment themselves when grown together. Asplenium scolopendrium (Harts Tongue fern) has long strap leaves which are lime green in colour and contrast in mixed fern plantings against the darker ferns. Polypodium vulgare (Common Polyploidy fern) has arching, feather like leaves. Phlegopteris connectilis (beech fern) has 12" long fronds that are light green in colour, but it has a creeping habit and will spread slowly and gracefully around an area.

DRY ROCK BASES or in a rockery bed
Use the smaller Asplenium ceterach (Rusty Back fern) grows to only 8 inches wide and high ideal for rockeries. Cystopteris bulbifera (Bladder fern) so named as it gets small bulbils on its fronds (more to these later) is quick to establish and spread. but maintains a small height of 1ft. Also suitable are Blechnum penna-marina (Hard fern) which is only 6" tall and spreads sideways.

STREAM SIDES
Again M. strutheopteris is ideal for these area's. Another plant that loves to be near semi-permanent damp ground is Osmunda regalis (Royal fern) and it is indeed kingly in appearance. At 6ft high and upto twice that in width mature specimens will quickly take pride of place, at a streams edge. Also known as the 'flowering' fern it produced fertile fronds at the same 6ft high which are rusty brown in colour. Both Matteuccia and Osmunda will thrive in good lighting as long as the roots remain damp. Onoclea sensibilis (Sensitive fern) also prefers streamside locations. This will be at home in the more dappled shade of stream side trees, as it can be scorched by too much direct sunlight. It is a good creeping fern and will quickly form a good green area. The Foot ferns are also extremely beautiful to have along side a stream the hardiest is Davallia mariesii or the Squirrels Foot fern, its fronds form loose layers one on top of each other. Needs frost protection.

WALL CREVICES
Ferns do not need very much medium to grow in, as long as their roots are in the medium and there is water getting to the they are happy, rainwater percolating through a dry stone wall is idea. Even better if the wall planting side is North or West facing. Where plants are difficult to grow, ferns will flourish. Ferns ideal for this situation include some of the Aspleniums, A.nidus, A.rhizophylum, A.scolopendrium and A.trichomanes which like the lime in the mortar.

ARCHITECTURAL FERNS
Ferns can be used as eye catching attractions and centre-pieces. In a border you could use Blechnum tabulare which at 1 metre long fronds it has a 2 metre spread. It also has fertile fronds that are a rich brown against the green fronds. The most prominent and increasingly popular Tree ferns Dicksonia antartica are impressive and staturesque. These require frost protection of the crowns and should also only be watered at the crowns, so go for something that is at a convenient height for watering. Use them as centre-pieces in patio area's to break an area up or use at the end of a long walk to draw the eye down the vista. Other tree ferns of note for mild areas are the Cyathea's but be warned these are 'trees' they can grow to an impressive 25ft or even 50ft in the case of Cyathea medullaris (Sago fern). For a conservatory a tree fern is an ideal species as the give a classic victorian air to a glasshouse of any kind. If a tree fern (Dicksonia sp.) gets excessively big for a conservatory the plant should be lifted, during the dormant winter season; and a portion of the 'trunk' cut off to make the fern the required length.

INDOOR FERNS

Nephrolepis - Nephrolepsis - exaltata Bostoniensis

Many ferns can be grown indoors, and frost tender plants need to be. They do not require much care and thrive in many places in the home that any other houseplant would not. I have found that the only place that they do not like is above a radiator where they are too dry. Ferns like humidity, this can be raised indoors in potted ferns by sitting the pots on a plate or dish with granules of clay or small stones in the bottom. This should be kept topped up with water to envelop the fern in a moist micro-climate. If you are lucky enough to have an indoor water feature in your conservatory, and ideal fern is Lygopodium japonicum, (Japanese climbing fern) this will grow up a water feature or wall next to a walled water spout. The fern will grow upto 6ft. Soil requirements are as described above, watering should be made (with rainwater if possible) when the plants are almost dry at the surface of the pot. Common houseplant ferns that are readily avaiable are Adiantum capillus~veneris (Maidenhair fern) or any of the other Adiantums are ideal for indoors. they are as their name suggest light airy ferns.
Also common and easy to grow are the Nephrelopsis - Nephrolepis - species (Sword ferns) these are the ferns commonly seen in shopping complexes (malls) overhanging ledges. They are ideal for bathrooms and hang over ledges of windows gracefully. When it rains the wife runs out to get the washing in whilst I run out to put my ferns on the lawn. They really do enjoy a good dowsing of rainwater.
A fern to use in an indoor tree to create a tropical feel is the Platycerium sp. (Staghorn ferns) They have long broad and almost rubbery plate like fronds and add that essence of epiphytic growth in an indoor conservatory.

FERNS AND THEIR PROPOGATION.
Many ferns can be grown from spores but this is not the only way.
DIVISION
Garden ferns such as the Dryopteris and Athyriums can be divided much the same as a perennial herbaceous plant. During spring just as the fronds are about to come. Take a sharp spade and dig the plant up. with its rootball, using a hard downward cut, divide the crown in half as long as a portion of the crown is kept whole with its roots the divided plant will survive. A large Dryopteris can yield 3 or even 4 plants from one mature plant. The plants will be ready to divide again in 3-5 years depending on how many divisions are made.
Creeping ferns such as the Cystopteris species again can be divided using a sharp spade as long as the roots are intact wth the fronds. Thus a large area can be covered from a few plants in 3 seasons growth.
BULBILS
These ferns are the next easiest types to propagate from.
In some species small bulbils are developed on the fronds. Species of note are Asplenium bulbiferum, Polystichum setiferum [Divisilobum group] these have fronds that seem to bend under the weight of the bulbils. Take a large frond weighed down with bulbils. Place it on a seed tray of suitable fern growing material (see above) and peg it down to make contact between compost and bulbils. Water the seed tray but do not soak. Enclose the whole tray in a polythene clear bag and leave on a warm windowsill or in a cool greenhouse in summer. The bulbils will then root into the compost after a few weeks. These can then be cut from the parent frond and potted up individually and kept in a warm, moist and light place, until they are large enough to be potted on as single plants.
SPORES
By far the most taxing way to propagate ferns, BUT can be one of the most rewarding.
On the underside of the fern fronds are small sacs called sori. In these are the spores that provide ferns with the unique method of reproducing, which they have done since prehistoric times and has made them so successful as land plants. Spores should be collected just as the sori appear to be starting to lift off the frond and in most cases start looking like a paper spot on the frond. If they are brown its too late. Lay the frond on a piece of white A4 paper in a wind free place this will collect the fine spores onto the sheet. Sterilise a pot of compost mixture by pouring boiling water through it. Leave to cool off. Gently scatter the collected spores over the surface of the damp compost. Leave in a propagator in a warm light place or cover with a polythene bag and leave on a window sill. The spores should be lightly mist sprayed every 3 days to maintain humidity. within a 2-3 months you should have a carpet of green moss like growth on the top of the compost. This is the sexual stage of the ferns and this is where new ferns will come from. This should be gently lifted in small clumps and and further divided into smaller area's and placed on the surface of some newly sterilised pots of compost. About a dozen per 6" pot is suitable. These can then be returned to the propagator or windowsill. Within a further few weeks you will see small fernlets appearing in the patches. When this occurs they should be potted up into cells to encourage root growth of the individual plants. Carry on potting on until they are individual ferns.
Spore propagation may be the only way to get a treasured fern from a friend who does not want to divide a rare or hard to obtain plant. It is a bit of an effort and slightly harder than growing flowering plants. But is an excellent way of getting lots of new ferns!

dfilixmas@aol.com (Ian)