PRACTICAL BOOK OF GARDEN ARCHITECTURE 



As a help to aerate the water, and keep it sweet 

 and free from objectionable features after the algae 

 and mosquitoes have been destroyed, it will be im- 

 portant to plant intelligently within the pond. The 

 plants that best supply the required oxygen and 

 keep the water pure are the sub-aquatics, like the eel 

 grass and the giant water weed, and others of this 

 nature that are natives and certain to flourish. Then, 

 for plants to beautify the lake, if it is undesirable to 

 establish water lilies, except along the border, try 

 some of the floating plants that are easily controlled. 



The water hyacinth is one of the best, as it de- 

 velops rapidly, bears quantities of the blue, hyacinth- 

 like blossoms, and makes a fine display without re- 

 quiring a place for rooting in the bottom of the lake. 

 This general favorite for northern lakes, botanically 

 known as EicJiornia crassipes, and also as Eichornia 

 speciosa, is the famous " million-dollar weed" which 

 became such a nuisance on the St. John's River, in 

 Florida, that it caused over a million dollars' worth 

 of damage in obstructing navigation. But there is no 

 danger of destructive development outside of the 

 mild southern climes. It is a tender annual farther 

 north, and unless care is taken to keep some of it 

 in the houses during the winter, it will be destroyed 

 by freezing. 



Another good floating plant for the garden lake is 

 the water chestnut, or water caltrops (botanically 



