372 MANUAL OF GARDENING 
the lateral branches will start near the ground and be stiff enough to 
withstand the winds. In most home gardens the plants are allowed 
to reach their full height, and are tied to stakes if necessary. The 
tall kinds reach a height of 5 to 8 ft. 
Dahlias are very susceptible to frost. After the first frost, lift the 
roots, let them dry in the sun, shake off the dirt, trim off tops and 
broken parts, and store them in a cellar, as for potatoes. They may be 
placed in barrels of sand, if the open cellar is not usable. Cannas may 
be stored in the same place. 
The tree dahlia (D. excelsa, but cultivated as D. arborea) is grown 
more or less far South and in California. It has not been much im- 
proved. 
Ferns. — The native ferns transplant easily to the garden, and they 
make an attractive addition to the side of a house, or as an admixture 
in a hardy border. The ostrich, cinnamon, and royal ferns are the 
best subjects. Give all outdoor ferns a place that is protected from 
winds, otherwise they will shrivel and perhaps die. Screen them from 
the hot sun, or give them the shady side of the building. See that the 
soil is uniformly moist, and that it does not get too hot. Mulch with 
leafmold in the fall. It is not difficult to colonize many of the native 
ferns in shady and protected places where trees do not sap all the 
strength from the ground. 
Probably the one fern grown most extensively as a house-plant is 
the small-leaved maidenhair fern (or Adiantum gracillimum). This 
and other species are among the finest of house plants, when sufficient 
moisture can be given. They make fine specimens as well as serving 
the purpose of greenery for cut flowers. Other species often grown for 
house plants are A. cuncatum and A. Capillus-Veneris. All these do 
well in a mixture of fibrous sod, loam, and sand, with ample drainage 
material. They may be divided if an increase is wanted. 
Another fern for house culture is Nephrolepsis eraltata. This is 
no doubt the most easily grown of the list, flourishing in a sitting- 
room. A varicty of N. exaltata, called the Boston fern, is a decided 
addition to this group, having a drooping habit, covering the pot 
and making a fine stand or bracket plant; and there are now several 
other forms of it suitable for the best. window-gardens. 
