Larkspur
Delphinium formosum.
LARKSPURS may be divided into two classes, the annual and the perennial. The figure represents the finest garden plant of the family, and one of the most generally useful and accommodating of all known hardy perennials. The annual larkspurs are the cross-bred descendants of Delphinium ajacis and D. consolida, and they comprise a series of very distinct forms severally known as dwarf, rocket, branching, candelabrum, hyacinth-flowered, stockflowered, and ranunculusflowered. These are all worth cultivating, but for general purposes the best are the branching, the hyacinthflowered, and the rocket, which may be had in all colours except shades of yellow, of which the genus Delphinium gives no examples, unless we recognise D. ochroleucum as a yellow, which, properly speaking, it is not. The annual larkspurs are amongst the gayest flowers of their class, and the bright blue varieties are brilliantly beautiful. They are unfortunately of brief duration when sown in spring, and spring sowing of annual flowers prevails so generally that not many growers of such have seen the best sorts in the best condition. The larkspurs make finer spikes of flowers and last much longer when the seed is sown in autumn, and this practice provides the garden with their agreeable verdure through the winter, for the plants are quite hardy, and fine clumps often appear from self-sown seeds. The parent species are limestone plants, and the garden varieties thrive on dry calareous soils.
Perennial larkspurs are raised from seeds and divisions; they are quite hardy, and will thrive in almost any soil or situation. In common with a majority of the plants that command attention in the garden, they make a finer growth in a good soil than in a bad one, but it is worthy of special note that a hot dry soil is well adapted for them, provided the aid of a little manure is afforded. When a collection has been secured, it will be good practice to lift, and if needful divide and re-plant every three years, the soil to be well dug over and liberally enriched with the clearings from an old hotbed. In any case of failure, winter damp may be suspected as the cause, for as limestone plants, a somewhat dry soil suits larkspurs far better than a heavy soil retentive of moisture.
The raising of plants from seed is a quite simple matter, but needs a little care, on account of the liability of the young plants to "damp off" if too freely or too frequently watered. The best time to sow the seed is in summer or autumn, as soon as it is fully ripe, but spring sowing usually answers and is generally practised. Sowing on the open border is not good practice, but self-sown plants which appear on their own account may always be left to manage their own affairs until large enough to be worth transplanting. Sow in shallow pans or boxes, using for the purpose good sandy loam without any manure; sow with care, to distribute the seed evenly and thinly, and cover with a mere dusting of soil. Keep the seed-pans in a frame, and lay slates or squares of glass, or even newspapers, over them to prevent evaporation, for it is always good practice to get up seeds by the aid of the original moisture of the soil, without giving any water until the young plants have made a fair start. As soon as the plants appear the coverings must be removed and the frame must be cautiously ventilated, so that by the aid of light and air, without exposure to a roasting sunshine or a frosty east wind, they may grow stout rather than tall, for seedlings that are "drawn" through being kept too close, and lacking light and air, will be weak in proportion to their slenderness, and a very slight accident, such as a little too much water when the weather is cold, may kill them outright. As hardy plants, larkspurs need no coddling, but protection and encouragement may be afforded without detriment to their natural vigour. The after-management consists in planting out in other pans or on an open border of kindly soil, to make free growth preparatory to planting them out. Where the soil is naturally dry and calcareous, autumn is a good time for transferring them to their permanent stations, but where the soil is heavy, it is advisable to defer the planting until spring, provided the nursery bed to which they have been transferred from the frame is well drained and in some degree sheltered. Division of the roots is best accomplished in the spring, especially in places where winter damp is a known enemy to plants. None but an expert should cut the roots into small pieces, for the smaller they are the more careful nursing will they need in the way of shading and watering.
Delphinium formosum, the most generally useful of all this family, was largely employed a few years ago as a bedding plant associated with scarlet pelargoniums. The two kinds of plants being put out in alternate rows, the flowering shoots of the delphinium were carefully bent down and fixed with pegs, and thus the flowers were produced nearly on a level with those of the pelargoniums, the result being a very gay blending of the most brilliant blue with the most fiery scarlet.
The garden varieties of delphinium number about one hundred. Amongst the best of the single varieties are Formosum, Madame Hock, Barlowi, Lavender, and Belladonna. Conspicuous for beauty amongst the double varieties are Madame Geny, Roi Leopold, Hermann Stenger, Keteleeri, and Azureum plenum.