1216 



FERNS 



FERNS 



Cultivation of hardy ferns. 



The hardy ferns are easy to transplant and tenacious 

 of life under adverse conditions, but since the beauty 

 of fern foliage is brought out only by luxiu-iance of 

 growth, it should be the aim to plant only where such 

 can be secured. 



Ferns in general require positions in which the soil 

 retains an even amount of moisture at all times. Most 

 species do not grow well in a cultivated border or where 

 the space between the plants is not mulched or given a 

 ground cover of mosses or other plants which hold 

 the temperature and moisture of the soil siu-face more 

 evenly and allow the ferns to grow roots near and on 

 the surface of the ground. Also when the earth is 

 bare between the plants, the rains dash mud on the 

 under side of the fronds — a condition under which no 

 fern can thrive. However, some of the stronger-grow- 

 ing species, as the osmundas, because of their height 

 and strong deep roots will do well in a cultivated border. 

 A study of the soil surface where the fern is growing 

 well in the wild will show about what is necessary. 

 Some ferns, as the maidenhair (Adiantum), have 

 strong wiry stems which will push up through a very 

 heavy covering of leaves, while other species, as all of 

 the evergreen ferns, grow in positions in which the 

 annual fall of leaves does not remain on their fronds. 

 The larger number of ferns prefer no heavier mulch 

 than is made by the death of their own fronds, which 

 naturally fall away from the center of the plant, mulch 

 the surrounding soil but leave the crown of the plant 

 uncovered and unhindered for its growth in the spring. 

 Many of the smaller ferns which have neither deep nor 

 strong creeping roots require a ground cover of other 

 plants or simulated conditions to prevent their being 

 heaved out of the ground during the winter. A number 

 of species with strong creeping roots as Dennst^dtia 

 puncHlobula {Dicksonia pilosiuscula) and Dryopleris 

 {Aspidium) novahoraccnsis eventually form thick 

 masses which completely cover and fill the ground 

 with roots. When this condition has been attained, no 

 soil mulch or cover is needed, and even the old fronds 

 had best be removed before growth starts in the spring. 

 Ferns may be separated into two classes by their 

 stems: (1) those with creeping stems; and (2) those 

 having a central crown or cluster of crowns. 



Those with creeping stems spread and form large 

 masses. They not only send up a crop of fronds in the 

 spring but continue to grow new fronds during the 

 season. This class of ferns may be transplanted at any 

 season with ordinary care, in fact the fronds may be 

 mowed off and the roots taken, up in sods and relaid 

 like turf, but better results will be secured with more 

 care to preserve the younger and newly started fronds. 

 Those ferns with distinct crowns naturally send out 

 only one set of fronds each year. This class of ferns is 

 best moved after the plants have ceased growth in the 

 fall or before growth starts in the spring. Especially 

 is this the case with those species having deciduous or 

 fragile fronds which easily become wilted or broken. 

 When transplanting while in leaf, it is necessary to 

 preserve fully half of the fronds to insure a good growth 

 the following year. The evergreen species, as the 

 Christmas fern (PolysHchum or Aspidium acrosti- 

 choides), Dryoptens {Aspidium) marginalis and others 

 with hard coriaceous foliage, can with reasonable care 

 be transplanted at any season of the year. 



In general, the soil for ferns should be rich in humus 

 and mineral matter and sufficiently friable to allow 

 penetration by the fine roots. A heavy clay is not 

 satisfactory but may be corrected by the addition of a 

 sandy soil and thoroughly rotted manure or leaves. 

 A pure leaf-mold is not a good fern soil because it is 

 lacking in minerals and is too light and loose for 

 any fern except the Adiantum. A good sandy loam 

 with too little clay to bake and not enough vegetable 



matter to be spongy will suit the larger part of ferns. 

 It will be noticed that most species of ferns with 

 crowns grow in the wild where their roots reach through 

 the surface mold to a more mineral soil underneath ; in 

 fact they often grow in apparently poor yellow loam. 



The following ferns grow luxuriantly in full sunhght 

 with suitable conditions of soil and moisture: Ptcris 

 aquilina, Onoclea scnsibilis, Dennstiedtia puncHlobula 

 {Dicksonia pilosiuscula), Dryopleris {Aspidium) novor- 

 boracensis, and the osmundas. 



Practically all the remaining species prefer more or 

 less protection from the direct rays of the sun, but 

 darkness or dense shadow is not required. Even the 

 species which grow in deep, dense shade apparently 

 need only the humid atmosphere found there, since 



1491. Dryoptens simulata. 



near waterfalls and springs they grow in the open. In 

 mountainous regions in which the atmosphere is cool 

 and not drying, many species grow in full sunlight 

 which require more or less shade in drier chmates. 

 Among such might be mentioned Asplenium Filix- 

 fcemina, A. acrostichoides, Phegopteris hexagonoptcra, 

 D. polypodioides, Dryopleris {Aspidium) Thelypteris, 

 D. cristala, Onoclea Slruthioptcris, Woodwardia vir- 

 ginica, and W. anguslifolia. 



There are about seventy-five native American species 

 which can be grown in northern gardens, and also a 

 good number of quite distinct varieties. There are 

 hardy species in foreign countries so that a complete 

 collection of hardy ferns would probably reach 150 

 species. 



The following species not natives of the United States 

 are hardy at Philadelphia: Dryopleris chrysoloba, D. 



