Calceolarias are of two kinds, herbaceous and shrubby. The shrubby varieties are grown as bedding plants during the summer months. They are usually raised from cuttings of side-shoots inserted in sandy soil in late summer. These need only a little protection during the winter, and a sheet of glass that will exclude severe frost is sufficient.
The herbaceous calceolarias are grown as greenhouse biennials. Seed is sown at any time from May to July, though June sowings are regarded as best. Start the seeds in pans, placed in moist heat. Just cover the seeds with a very fine dusting of soil.
As soon as the second leaves have appeared, prick off the seedlings into pots. Do not waste any seedlings, as the weaker ones often prove to be the best colours. As the plants grow, move them into larger pots until they reach an 8-in. Size pot. Occasional doses of liquid manure will encourage the development of strong plants that will flower well during the second season.