ADIANTUM 



ADIANTUM 



217 



65 F. The soil should be composed of rich loam and 

 leaf-mold in equal parts, and should be kept moderately 

 moist. Some of the most useful ones for general pur- 

 poses (given under their trade names) are: A. semulum, 

 grows about 12-15 in. high, and has very graceful dark 

 green fronds; A. helium, a dwarf, very compact species, 

 6-8 in.; A. cuneatum, A. cuneatum var. grandiceps, with 

 long, heavily crested, drooping fronds; A. cuneatum 

 var. variegatum making a neat specimen; A. concin- 

 num, gracefully drooping dark green fronds 15 in. 

 long, with overlapping pimue; A. continuum var. te- 

 tum, of upright growth, is 24 in. high; A. decorum 

 very useful, 12-15. in., and has young fronds of a 

 pleasing metallic tint; A. excisum var. mullifidum; 

 A. formosum; A. Fergusonii; A. fragrantissimum; 

 A. pubescens; A. tenerum and var. roseum; A. Wie- 

 gandii; A. LeGrandii, very dwarf; A. mundulum, a 

 very neat, dwarf species; A. rubellum, a dwarf spe- 

 cies with mature fronds light green, young fronds of 

 a deep ruby tint. The above may easily be grown from 

 spores, if sown on a compost consisting of half each of 

 finely screened clean soil and leaf-mold or peat, and 

 placed in a moderately moist and shady place in the 

 greenhouse in a temp, of 60 F. To be grown most 

 economically, they should be transplanted in clumps 

 of 3 or 4 plants as soon as the first pinna; have appeared, 

 and, as soon as strong enough, potted off, either in 

 clumps or singly. Some very desirable species to grow 

 into large, tall specimens are: A, xlhiopicum, A. 

 Bausei, A. Collisii, A. Fergusonii, A. formosum, A. 

 Lathomii, A. peruvianum, A. princeps, A.rhomboideum, 

 A. Sanctse-Calharinx, A. trapeziforme, and A. Wil- 

 liamsii. The following are also recommended for special 

 purposes: for fern-dishes, A. fulvum; for cutting, A. 

 gracillimum. The following kinds are economically 

 prop, by division, temp. 65 F. : A. Farleyense, the differ- 

 ent varieties of A. Capillus-Veneris, A. rhodophyllum, 

 A. assimile. Some kinds, as A. dolabriforme, A. cau- 

 datum and A. Edgeworthii, form small plants on the 

 ends of fronds, which may be detached and potted 

 separately, and if kept in a close atmosphere will in a 

 short time grow into choice little plants. Temp. 

 65-70 F. (Nichol N. Bruckner.) 



The following directions (mostly for commercial 

 growing) are prepared for this entry by James C. Clark: 



Adiantums, when grown in large quantities, are best 

 propagated from spores sown in pots or pans, 6-inch 

 being a good size, pots being preferred to pans as they 

 maintain a more constant and equal moisture. The pots 

 should be filled with two-thirds good drainage (coal- 

 ashes or potsherds are very suitable), top-dressed with 

 one-third sterilized loam mixed with one-tenth part of 

 sharp sand finely sifted and evenly pressed down in the 

 pot, so that the top of the soil will be about J4 inch 

 below the rim. The pots should then be placed on a 

 greenhouse bench, under shaded glass, and where a 

 temperature of 65 to 70 can be maintained. Then 

 water until they are thoroughly soaked (and to make 

 sure that they are wet, water again; it is impossible to 

 make too wet) . Allow to drain for an hour or so and then 

 dust the spores evenly, and as thinly as possible, over 

 the surface and cover immediately with glass. The 

 glass should remain on, and no water should be required 

 or given, unless by dipping, until the spores have devel- 

 oped to the prothallus stage, when it will be advantage- 

 ous to give a slight watering, using a very fine rose, and 

 raise the glass 8 inches above the pots, supporting so 

 that a free current of air can pass directly over the pots. 



At this stage of their development adiantums, like 

 all other fern prothalluses, must never be allowed to 

 become dry. At the same time, great care must be 

 exercised so that there will be sufficient air to prevent 

 damping and yet no direct draft either from the heating 

 pipes or ventilators to cause wilting or drying out of 

 the pots. 



As soon as the first real fronds appear (generally in 



eight to twelve weeks from time of sowing, according to 

 season of year; eight weeks in spring and summer; 

 twelve weeks in fall or winter), the seedlings should be 

 transplanted in small clumps of three to five seedlings 

 each, into flats or seed-pans, spaced about 1 inch apart, 

 and placed in a close warmhouse, in a night temperature 

 of 65 to 70, until the seedlings show signs of taking 

 root and making new fronds, when the temperature 

 may be lowered to 60 at night and 65 to 70 in the 

 day. This temperature will be found to suit all adian- 

 tums (except A. Farleyense), in all stages of their future 

 development. 



When the transplanted seedlings are about 1 inch 

 high, they may be placed in small pots and repotted 

 into larger ones as soon as they require it. In potting, 

 a good compost consists of nine parts of loam and one 

 part of well-rotted cow-manure, the pots being provided 

 with good drainage, especially the larger sizes. In pot- 

 ting, the crown of the plant should be placed deep 

 enough so that it will be covered with % to % inch of 

 fresh soil, making the soil only moderately firm (never 

 hard). Place the plants in a greenhouse, spaced so that 

 there will be a free circulation of air all around the 

 plants, the glass moderately shaded from March 15 to 

 November 1, and all shade removed during the winter 

 months, giving as much ventilation (without draft) as 

 possible. The soil should be kept moderately moist at 

 all times and a good atmospheric moisture maintained 

 by wetting down the walks, but at no time should the 

 foliage be wet more than possible. Well-drained, solid 

 beds are better adapted to the growth of adiantums than 

 tables, but, if grown on the latter, a )^-inch overhead 

 heating-pipe over each table, say 18 inches above the 

 foliage, will be found of great assistance in overcoming 

 the condensation that is so destructive to the foliage 

 when the plants are grown on tables. 



Treated as above, adiantums can be grown into 

 6-inch pot specimens in one year from time of sowing 

 spores, and when grown rapidly are seldom troubled 

 with insect pests, unless it be green-fly, which can be 

 kept under control by a weekly application of nikoteen, 

 using two ounces to five gallons of water, applied in as 

 fine spray as possible. 



Specimen adiantums, in 8-inch pots or larger, can be 

 grown in the same-sized pots for several years, provided 

 they are slightly rested during the winter months by 

 being kept on the dry side and in a lower temperature, 

 say 45 to 55. In February the plants should be re- 

 moved from the pots, the drainage examined, a little 

 of the top-soil removed, and then top-dressed with old 

 rotted cow-manure, and the plants returned to a grow- 

 ing temperature and given more water as required. 

 Feed either with liquid manure or dust with pulverized 

 animal manure every second week during the growing 

 season. Some of the finest specimen adiantums in this 

 country have been grown in the same-size pots for five 

 to seven years. 



Scale sometimes attacks old specimen adiantums, 

 and there is only one remedy, rest the plants by 

 keeping to the dry side and in a cool temperature for 

 about a month; then cut off all the fronds clear down 

 to the crowns, and treat the same as old specimen 

 plants. 



For amateurs and small growers, all adiantums can 

 be propagated by division of the crown and rhizomes. 

 This is best done in January and February. Wash off 

 all soil and cut the roots off as close to the crowns as 

 possible. Then divide to single eyes. Place the eyes 

 in sharp sand, merely covering them. Place in a situa- 

 tion such as advised for spores and cover with glass; 

 when the first fronds appear, treat exactly the same as 

 recommended for seedlings, when they will make plants 

 about as quickly and equally as good as those grown 

 from spores. 



Adiantum Farleyense, being a sterile species, must be 

 propagated by division. It requires the treatment recom- 



