The Boronias are a genus of plants some of which should be in every collection. They are very free - flowering and sweet - scented, and besides being useful for cutting and general house and conservatory decoration, are among the best of exhibition plants. They are not now nearly so much grown as they formerly used to be, and as their merits deserve. B. serrulata especially, makes a splendid specimen when well grown, but it takes a deal of care and attention to maintain it in good health, as it has a habit of going off in the most unaccountable manner, and therefore requires constant watchfulness in the way of watering, etc.

The Boronia is a native of the Australian continent. The soil best adapted to its wants should consist of fine fibry peat and a good portion of sharp sand, with some small pieces of charcoal incorporated therewith. Though the Boronias are greenhouse plants, they are very much benefited by getting a little extra heat in spring, just when growth commences, and until they have fairly started into growth, when they may be gradually introduced to the cooler temperature of the greenhouse. They are propagated by cuttings of the half-ripened wood, which should be inserted in pure silver sand in a properly prepared pot, and covered with a bell-glass. They are somewhat liable to damp off, and therefore, to reduce the chance of this to a minimum, the bell-glass should be taken off and wiped dry inside every day. As soon as the cuttings have made roots, they must be potted up singly into thumb-pots, and kept growing on in a mild heat. They will require to be kept close and shaded for a time, until they start into fresh growth, when the shading may be discontinued, and a little air given on favourable opportunities. The aim at first should be to get nice stocky plants, and therefore pinching the points of the shoots must be resorted to, whenever they have made sufficient growth to admit of it.

When the small pots have got filled with roots, they must be shifted into larger pots. The shifts, however, should never be large, as it is a very fine-rooted plant, because if large shifts were given, the soil would be more likely to get soured by repeated waterings, before the roots had permeated the ball. The pot should in no case be more than two sizes larger than the one the plant is in; and it will be even safer should they be only one size larger. In potting, the soil should be rammed in pretty firmly, so that it may not retain more water in suspension than what is necessary for the wants of the plant. As the season advances the plants should be introduced into a cooler and more airy structure, in order that the wood may be thoroughly ripened before winter sets in. The temperature during winter should be maintained at from 40° to 50°. They should be frequently syringed, in order to keep them free from scale, to which they are somewhat subject, as also a kind of smut or fungoid growth, which frequently gathers on the leaves and stems, rendering them black and unsightly, and injuring the health of the plant.

In order to keep them clear of these pests, nothing beats tepid water in which a little soft-soap has been dissolved : it is the most harmless, and one of the most effective of insecticides. The foliage being so small, it is next to impossible to hand-wash it, so the syringe should be in frequent use. Boronia serrulata and B. Drummondii are the two best of the species, and flower from the middle of April till the end of June.