Propagating dahlia

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Contents 1 Propagating Dahlia - Introduction 2 Growing Dahlias from Seed 3 Dahlia Propagation by Cuttings 4 Dahlia Tuber Propagation

Propagating Dahlia - Introduction

In the Northern States the tubers of dahlia are taken up about a week after frost has killed the tops and before the ground has become frozen, and stored like potatoes in a cellar or in a dry room free from frost.

What are termed dry pot roots are raised from cuttings in three-inch pots placed on ashes in a frame to stop the roots from penetrating the soil, being grown in the summer and allowed to dry off in autumn. They are then taken out of the pots and stored away like large tubers. These dry pot roots make plants fully equal to those grown from large tubers.

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Growing Dahlias from Seed

Dahlias can be grown easily from seed so as to produce flowers the first year. For best results sow early in March in shallow pans.

If the gardener has artificial heat at his command in February and March, the raising of a small batch of dahlia seedlings is a fairly easy matter. Seed of the various classes of dahlias either decorative, cactus, pompon or single can be obtained cheaply, and if it be sown in sandy soil in pots or boxes placed in genial warmth it will germinate with astonishing rapidity.

As soon as the seedlings are an inch or so high and have formed a pair of leaves, they should be pricked off singly into a thumb pot which has previously been filled with soil composed of loam, leaf mould and sand. The pots should be placed in an airy position on the greenhouse shelf, and be kept moderately moist. When the roots have permeated the soil and are touching the sides of the pots, the young plants must be potted on into five-inch pots and be inserted in soil that has been enriched by the incorporation of some old and well-decayed manure.

Towards the middle of April, when the atmospheric conditions ought to be becoming more genial, the plants can be placed in a cold frame, and gradually hardened off preparatory to planting out during the opening days of June.

Dahlia Propagation by Cuttings

A commoner method of propagation is by cuttings. When the old stools are taken from their winter quarters they will probably present a shrivelled-up appearance, as though all the life had been dried out of them. Their owner must not, however, be deceived by this.

If he places them in a box, or on the greenhouse bench above the hot-water pipes, scatters some fine soil loosely round them, and sprinkles them at intervals with water through a fine-rose can, the roots will speedily be restored to their wonted condition of plumpness. In a few days strong young shoots will be sent up from the crown of the tubers, and it is these which, with proper treatment, will produce vigorous flowering plants during the autumn. The cuttings should be detached from the tuber when they are about three inches long. The stem must be cut through horizontally immediately beneath a joint, from which in time the new roots will be thrown out. Thus properly trimmed, the cutting should be inserted in a thumb pot filled with sandy soil.

For a day or two after the cuttings have been potted they will probably present a very sorry appearance. They will be limp, and will hang helplessly over the side of the pot. But this is only a temporary relapse. If the warmth of the house or hot-bed frame be well maintained for a time, the cuttings will soon recover their erect and sprightly appearance, and will rapidly establish themselves. Potting on will be necessary, as in the case of seedlings, so soon as the small pots are filled with roots, and their transference to a cold frame to harden off should follow a month or so later. The principal point to bear in mind is the need for avoiding forcing methods. These will result in leggy growth, a debilitated constitution, and poor flowers, whereas the aim should be to produce sturdy plants by giving them all the fresh air that is possible during the earlier stages of their growth.

Dahlia Tuber Propagation

But it may be asked : " How can dahlias be propagated without the aid of glass or artificial heat ? " The answer is, " By division of the old tubers." If this plan be adopted, however, it should not be put into operation until towards the end of April.

The old tubers can then be divided. The piece of root potted up, and grown on in the window of a room facing south.

It has long been a common practice to divide the old stools, and plant them direct in the open ground late in the spring. The division must be done carefully. It is a mistake to suppose that each tuber if detached from the stem will produce a new plant. All the eyes from which growth can start are clustered at the crown of the old stem.

To the practised eye they are plainly visible, but if there is any doubt about it, it is a good plan to make a vertical cut through the stem and divide the tubers in two or more sections. The resulting divisions may then be planted in well-manured and deeply-dug ground, with the crown of the tubers four inches below the surface.

This fairly deep planting will ensure that no precocious growth is made until all danger of late frosts is over. Probably the divided dahlia will throw up many shoots at the outset. In that case the weakest of them should be thinned out, otherwise the flowers will be few in number and poor in quality.

About the middle of May it will all depend upon the state of the weather young dahlias that have been struck from cuttings or raised from seed will require to be placed in a cold frame. Here they should be hardened off by keeping the lights raised at every available opportunity until they are ready for planting out in the first or second week in June.

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