This extensive genus includes some very handsome hardy perennial plants. L. cardinalis, the cardinal flower, is one. They are best raised from seed sown in August and wintered in a coldframe and placed in their permanent position early in the spring. This method is suited to a great many of our best hardy perennial plants that do not divide easily.
The dwarf tender species of lobelias are of most interest to us, although they are not of such value here as flower garden plants as they are in the cooler summers of Northern Europe. In Great Britain some of the best flower garden effects are produced by the blue lobelia, where they can be depended on to flower all summer. Here they are very gay out of doors till perhaps the middle of July, when they will go entirely out of flower and your design is left with a streak of dark green in place of the brightest of blues.
For hanging baskets, vases and veranda-boxes they are to us indispensable, and if not lasting all summer they add greatly in color when first used, and are not so much missed later, as stronger growing droopers take their place.
Select a few of the best plants in September, cut them back a trifle, and before a hard frost dig up and pot and give them a light, cool place. With a little more heat they will give plenty of cuttings, and both from the old plants and the young ones you will get all the cuttings you want, which root like the proverbial weed.
We like to grow them on hanging shelves, as it affords room to let them droop. We endeavor to be well supplied with plenty of lobelias in 3-inch pots with a thick growth of eight or ten inches long and just ready to flower about the middle or end of May, and this you can do from cuttings struck in February if pinched once or twice and given a good light shelf.
L. Erinus, with its varieties is the one most useful to us, the variety called speciosa being most in use. If seed of speciosa is sown you will get a number of varied forms, and some of those grown by us have originated locally. A good, free growth and a fine blue flower is what we select in speciosa.
Paxtoniana is another variety of Erinus which is still more straggling in growth, with light blue flowers with white throat.
The dwarf compact form of Erinus, compacta, which is so largely used in Europe, would be the best of all for bedding, but it is not to be depended upon here and is not of any other use. Seed of the varieties of Erinus can be sown in January and by the help of a hotbed in April and May would be large enough for bedding plants, but to have them in good order for our vases, etc., cuttings are much better.