Chapter 7. Propagation of Rock Plants-Marsh Plants-Shrubs

Rock plants may be propagated by several methods: they may be raised from seed; cuttings may be taken; they can be layered; with a great number the roots may be divided; of some, root-cuttings can be secured; and a few can be propagated by leaf-cuttings. We will describe in detail the various processes.

Sowing Seed

Many alpines may be raised from seed in the open where they are to flower; others must be sown under glass. The requirements of the individual plants will be found in the Alphabetical List of Plants, Chapter 12 which gives full cultural details.

Storing Seeds. Generally speaking, in ordinary cirumstances, seeds retain full vitality for one or at the most two years only. From this we gather that it is better to sow seed saved during the current year. If this is not possible, use seed of the previous season; or, at the utmost, not more than two seasons old.

If home-grown seed is to be used, the ripening seedheads should be watched and gathered before the seed is spilled. Be careful, however, to give the seeds ample time to ripen; do not pick them too early. The seed should be removed from the heads and dried in the sun on sheets of paper for a few days, and then sown, preferably under glass, as soon as it is ripe. The seeds of early-flowering species, if so sown, will more than likely furnish plants that will flower the following year. Seed bought from nurserymen and seedsmen is usually not available until autumn or the spring.

Seed should be stored in a dark, cool place; it must be kept dry and, above all, in an even temperature. It is best placed in tins with tightly-fitting lids, in thoroughly clean glass bottles (these must be kept in the dark), or in glazed paper impervious to moisture. Soft absorbent paper should not be used, as the seeds will either dry and shrivel up or, if kept in too moist a place, will get damp and will rot. Do not leave the seeds in their pods, as is so often advised, since after a time the pods dry up and draw both moisture and vitality from the seeds.

Sowing Seeds Under Glass

Most alpine plants can be raised from seed sown under glass, and the 76 soil for the seed pans should consist of a composition of two-thirds good loam and one-third leaf-mould, together with a good sprinkling of sharp silver sand. The compost should be sieved through a quarter-inch mesh and the soil for covering the seeds through a sieve even finer. This compost will suit the majority of alpines, but some are fastidious and require their own particular mixture; this they must have or failure will follow. For a plant's likes and dislikes, as regards composts, see the Alphabetical List of Plants, Chapter 12.

Mix the compost thoroughly, press it gently into the pan or box, and make a firm and level surface just below the rim of the pan. The seed pans should be drained by means of "crocks" or broken pots, an inch and a half to two inches of crocks being required in a box or pan five inches in depth; the crocks having been covered with a layer of well-rotted leaves or turf* about one inch thick.

Earthenware pans are preferable to boxes, as the earthenware keeps the soil more evenly moist than does the wooden box. The seed should be mixed with ten times its quantity of dry sand, and should then be sprinkled thinly over the soil in February or March. It must then be watered, not with a can, but by immersing the pans nearly to their brims, thus allowing the water to soak up from the bottom without disturbing the surface soil. Place the seed pans in a frame or greenhouse in moderate but steady heat (about 60 F.). A sheet of glass should be placed over the boxes, and the glass in turn should be covered with a sheet of brown paper to keep out the light.

Each day the glass must be lifted off the boxes so that the condensation may be wiped off, or the seeds will be kept too moist.

No further water need, as a rule, be given until after the seeds have germinated.

As soon as the seeds are up (in two or three weeks time, except in the case of certain kinds; the primula, for example, may take a year or longer), the glass and paper may be removed and the boxes must be lifted by gradual steps up to within six inches of the lights. If the box is left some distance from the glass, weak, straggling seedlings will result. The young plants must be given plenty of air, but should be shaded from the sun. In warm weather it is wise to water the seedlings in the evening, but in the colder weather the watering must be done before lunch-time, or there may be danger of the seedlings "damping-ofF." In the case of alpines it is better not to water overhead, but to provide moisture, as suggested above for newly-sown seeds, by immersing the pans almost to their rims and thus allowing the water to percolate evenly through the soil. By this means the foliage is not damped, and the danger of "scorching" and "damping-ofF" is reduced to a minimum.

Propagation Of Rock Plants

Sowing Seeds in a Frame. The seeds may be sown in a frame in exactly the same way as described for sowing in pans or boxes; the frame should be in a sheltered position, as it is essential to ventilate as much as possible when the weather is sunny and sufficiently calm.

Pricking-off the Seedlings. When the seedlings are sufficiently large to handle, they must be pricked-off an inch or more apart so that the leaves do not touch, and should be transplanted into boxes of light, sandy soil, which are again put in a position some six inches from the lights. An ordinary wooden seed label will be found very useful in raising the young seedlings from the soil. It should be inserted in the soil an inch or so from the seedling, whose roots may then be gently levered up without damage never should seedlings be pulled up between the finger and thumb, as this will sorely damage the roots. The seedlings should be transplanted so that the first pair of leaves show just above the soil. They must be set in firmly and should have the soil pressed tightly down round the roots and stems, though care must be taken not to injure any part of the seedling.

A thin dibble about the size of a lead pencil should be used to make the holes for the seedlings, and these must not be made too deep or the roots of the seedlings will not reach the bottom, and the air-pockets left under them will wither the roots. Do not "firm" the seedlings by pressing the earth round the stems with the fingers, but use the dibble, inserting it into the soil, in three or four places round the seedlings, about half an inch from them, and to the same depth as when preparing the holes. This will firm the soil all round the seedlings, right down to the bottom of the roots; the fingers would only press in the surface soil and the roots would be left loose.

Strongly-growing seedlings can usually be potted up at once, the process of pricking-off being unnecessary. In the case of seeds that germinate irregularly, the first batch of seedlings should be pricked-off as soon as they can be handled, and the seed pans should then be replaced so that the remaining seeds may germinate; for it should be remembered that the last seeds to come through usually produce the best plants. Such treatment is necessary with plants like the Anemone, Primula Auricula, P. Polyanthus or Primula.

After pricking-off keep the seedlings in a close atmosphere and shade them from the sun for a few days until they are well established in their new boxes.

Hardening-off and Planting-out. In March or April the seedlings should be moved into the cold frame. There they are hardened-off and are gradually allowed more and more air, until they are planted out very firmly in the open in May or at the beginning of June.

This is not, as a rule, advisable for alpines, but may be quite successfully carried out in the case of some of the more easy and vigorous kinds.

Weather for Sowing. Never sow in a cold, wet soil. Wait until the ground has dried sufficiently and until the weather really bids fair to be mild. It is false economy to sow before one feels sure of the weather, just on the off-chance of getting early plants. Dry weather should, therefore, be chosen for sowing, and if seed can be sown just before a gentle shower, or when the weather is likely to be showery, so much the better. Of course, there is a proper time for the sowing of every kind of seed (see Chapter 12), but, naturally, this cannot be specified in a series of general instructions, which must, necessarily, apply equally to all. The smaller the seed, the finer should be the soil in which it is sown.

The soil in which the seed is sown should be tolerably dry dry enough to crumble lightly when worked with the hand. It must not clot together in a pasty mass. Place or position that is to say, whether in the open air or under protection also forms an important factor with regard to the time of sowing.

Preparing the Seed-bed. The seed-bed should be situated in partial shade and should be sheltered from the north and east. The soil must be made as fine as possible, first by breaking up the lumps with a fork and then by raking it thoroughly until the earth is well pulverized. It should contain from ten to twenty per cent, of sand this will make it porous and will enable the air to penetrate freely through it. If the soil is not made fine in this way, many of the seeds will fall down in between the clods and will not germinate; those that do come up may have their tiny roots parched up, as there will be no fine soil through which they can work and so obtain nourishment and moisture. Too rich a soil must not be used, for the seedlings would become tall and straggly, instead of being short and sturdy, which is the ideal at which to aim. The bed must be pressed down firmly and should be left to settle for ten days before seeding. Water the bed thoroughly, if dry, and in March or April, or in late summer, sow the seed thinly in drills running north and south, if possible, and about six inches apart (for time, depth to sow, and distances apart for the different plants, see Chapter 12). Sowing in drills is much better than the "broadcast" method, in which the seed is scattered over the entire surface of the seed-bed, for it makes weeding more easy; this is especially so in the case of plants like the Juniper, Rhododendrons, Conifers, etc., where they have to stay in the bed for more than one year. It also saves seed and makes the operation of sowing more easy.

Thick sowing means that the seedlings will get drawn up and will be sickly; thin sowing secures short, sturdy seedlings.

Depth to Sow. Cover the seeds lightly with fine, sandy soil; the depth of covering required depends on the size of the seed. Minute seeds hardly need any covering at all, a mere sprinkling of sand is sufficient; medium-sized seeds must have a covering a little more than their own size in depth; and large seeds, such as those of the Iris, and those like the seeds of the A. Hepatica and Phlox, which do not germinate for two years after sowing, can do with almost half an inch of soil over them. Few seeds require a covering of more than an inch. Seeds may be sown slightly deeper out-of-doors than under glass, as the rain is liable to wash out any with too sparse a covering. A good rule is to cover the seeds with a layer of earth twice their own thickness. Do not pat down the soil after the seeds have been planted.

Seeds sown in heavy clay soil must not be placed so deep as those planted in medium loam; while in sandy soil a covering of nearly twice that given in a heavy soil will be required. Do not plant the seeds too deep, however, as if so planted, and they ever reach the surface at all, they will have used up most of their strength and energy and will make weak, straggly seedlings.

Should the soil of the seed-bed be very dry, the seeds should be soaked over night in warm water.

Watering the Seeds. As soon as the seeds have been covered, give them a good watering from a can with a very fine rose; the rose must be very fine or the seeds may be uncovered and washed away. Keep the soil uniformly moist, but not too wet; over-watering causes the seeds to rot and is the most frequent cause of failure. A few strands of black cotton, supported on small sticks, should be stretched across the bed to keep the birds away. If, before planting, the larger seeds are steeped in a weak solution of paraffin or red-lead, neither mice nor birds will trouble much about them.

Thinning-out and Transplanting. In a month or so the seedlings should be large enough to be pricked-off. This should always be done at the earliest possible moment. Delay in thinning and transplanting means that the seedlings become drawn-up and weakly; when they are eventually moved, the fibrous roots become torn and the seedlings will take much longer to become established. They will, in fact, never make such sturdy plants as those transplanted at the right time. In order that the roots shall not be torn, the seed-bed should be watered the evening before the day on which thinning is to take place.

The seedlings should be raised from the seed-bed by means of a small fork; each seedling may then be separated from its neighbours without any damage to its roots, and should be planted very firmly, by means of a small trowel, in a hole just large enough to receive the roots without cramping them or doubling them up, and care must be taken not to leave an air-pocket below the roots or they will soon be parched. If, as in the case of very tiny plants, the seedlings are to be thinned and not transplanted, the fork is not used to raise them, but the unwanted seedlings are pulled up between the finger and thumb, a finger of the other hand being pressed upon the soil to keep the roots of the other seedlings in place. The soil should be firmly pressed back around those seedlings left in the seed-bed or they will be likely to die off. If transplanting is done in the evening, the seedlings will have the cool night in which to recover, and will not be so liable to be scorched as when transplanted in the heat of the day. The reserve garden into which the seeds are transplanted must possess a sunny aspect, should have been well dug, and the soil, if poor, will be all the better for having had good, well-rotted manure mixed with the top three inches of its surface, which, in order to ward off slugs, must be dressed with just sufficient soot to blacken the surface of the soil. A further dressing of vegetable ashes will help to lighten the soil and furnish nourishment for the seedlings.

Veronica Gentianoides Narcissus Veriformis

Care Of Seedlings

In warm, dry weather the reserve bed should be well watered the day before it is to receive the seedlings, but it must not be made too wet, as the seedlings will not grow if it is made to "cake." The bed should be again watered after the transplanting has been done. If transplanting can be carried out in showery weather, so much the better.

Care of the Seedlings. In dry weather the seedlings should be watered (but not when the hot sun is on them) and the bed must be well hoed. Tepid water is far more congenial to them than cold water from the tap or a deep tank, and provided the soil is fairly rich, the seedlings should receive no manure until they approach maturity. A dressing of soot water is a sufficient stimulant; it is also a protection from slugs, and lessens the risk of "damping-off." There are also a number of effective insecticides on the market today against slugs.

Wintering the Seedlings. In warm and sheltered districts the young plants may be left in the open all winter, but in colder districts it is safer to winter them in a frame, where they should be placed in October. Light, sandy loam and a southerly aspect best suit most seedlings. As much air as possible should be given, but care must be taken to exclude frost and damp; very little watering should be necessary.

In November of the second season or in March of the third year the plants can be put out in their permanent positions in most districts. Should one be in an industrial area it is wiser to wait until April or May. Tender plants should receive protection during the second winter as afforded in the first. Slugs are the great enemy of young seedlings, and some good soil fumigant should be used to keep these at bay.

Soil for Cuttings. Fine silver sand is, perhaps, the best medium in which to strike small cuttings. A light soil through which the air can pass freely is essential to the well-being of all cuttings. That aeration is necessary is proved by the fact that cuttings will strike readily in coconut fibre, a material that is extremely pervious to air and which retains moisture for a considerable period. Powdered charcoal also forms a good medium. Perhaps the free access of air through the excellent drainage in such a position is the reason why cuttings root more freely when placed close to the side of the pot.

How to Take the Cutting. Cuttings should be taken of shoots that have ripened or which are beginning to ripen, because in wood which is attaining or has attained maturity the callus so necessary to root formation is more readily induced to show itself. The side shoots of plants, low down on the stem, are the best for cuttings, and should be taken when the sap is in full motion, because its return by the bark tends to form the callus, or ring, of granular matter from which the roots proceed. The leaves of a cutting must never be cut off, except in so far as may be necessary at its base in order that it may be inserted in the soil. The leaves are the lungs of the plant, and if they are cut, the sap that they contain will be lost to the cutting and prevented from passing downwards to form the callus. Cuttings of plants that are difficult to strike may frequently be induced to do so by making a ring round them, or by tying a piece of fine string round them for a short time before they are taken from the parent plant. The downward flow of the sap is arrested by the tightened ligature and a swelling is caused, which forms a callus from which roots are soon emitted. The cutting must be severed from the parent plant just below the ring or band, and the callus formed should be covered when the cutting is inserted in the soil.

There are proprietary articles which may be obtained from horticultural suppliers, that are a considerable help in endeavouring to seal the wound and so hasten the growth of the roots in the various dicotyledonous subjects.

In taking cuttings, strong sturdy shoots varying from three to twelve inches in length should be removed from the plant, with a very sharp knife, by a clean straight cut just below a joint. If it is possible to take a "heel" or small wedge-shaped portion of the old wood and bark with it, so much the better. It is then assured that the cutting has been taken where the pith is smallest and there is the greatest width of wood on which the callus will form. If too much heel is taken, it will tend to decay, so the wood must be cut back as near to the joint as possible. The joint need not necessarily be the junction of two stems; it may equally well be the "eye" from which a pair of leaves have sprung. When no "heel" is taken, the cut must be especially clean and just below a joint, but the joint itself must be left intact. The "heel," from which all ragged edges should be trimmed, when placed in contact with the ground provides a larger surface on which roots can form. The length of the cuttings is decided by the distance between the joints; when these are, say, an inch apart, the cuttings must be from three to four inches long and over half this length must be buried in the soil. Where the distance between joints is less, the cuttings may be shorter, but all hard-wooded cuttings should have at least two or three inches in the ground, and all cuttings must be inserted right to the bottom of the hole prepared for them.

Types Of Cuttings

Cuttings of hard-wooded shrubs, such as the Broom, Heath, Helian-themum, or Myrtle, are more difficult to strike than those of soft-wooded plants. Such cuttings are better if taken with a "heel" of the old wood attached, and kept fairly short and it should prove easy if the method mentioned on the previous page be used. Cuttings of free-growing hardy plants strike easily without care or attention after being inserted in the soil. The position for all cuttings should, of course, be sheltered and shaded from full sun, and although not necessary with hardy plants, most cuttings when planted in the open do better if covered by a hand-light until the roots have formed. The less hardy and less vigorous plants should be struck in pots or boxes in a cold frame or under hand-lights, while some require artificial heat or the bottom-heat of a propagating box. It may be taken as a general rule that cuttings of soft-wooded plants require more heat than those of hard-wooded plants. "Soft" cuttings, as a rule, should not be struck in the open as, apart from a little heat being desirable, the wind and sun would dry the moisture from their leaves and the roots would only form with difficulty. A glass covering is, therefore, necessary. Cuttings of soft-wooded plants strike best when they have not too much foliage to bear, and should have the stems shortened to two or three joints beneath the point from which the foliage springs. Never make the cuttings longer than necessary. In the case of the less hardy plants the soil should be stored in a warm greenhouse for a few days before the cuttings are inserted, and rooting will be more certain and prompt if the cuttings are watered with lukewarm water and one of the new solutions.

There are several plants, like the pansy or the honeysuckle, whose stems, when mature, are hollow and useless for ordinary cuttings. In such cases the young shoots must be struck, and these taken with "heel" or at a node.

Shrub cuttings may be taken at three distinct periods, first in autumn when the wood has hardened and is quite mature; secondly in September or August when the shoots have half matured; and thirdly when the shoots are beginning to ripen in early summer; the latter time is, perhaps, the best of the three. With many of the hardier shrubs the cuttings may be struck in sandy soil in a sheltered bed in the open {see Chapter 12), provided the wood is fully ripe. Half-matured cuttings, even of hardy shrubs, must, however, be treated like those of the less hardy natures and should be struck under glass. Cuttings of hardy evergreen shrubs are also best struck under glass, not because they need heat, but because a close, steady and fairly moist atmosphere is required {see Propagation of Shrubs).

When cuttings are struck in pots or boxes, the latter should be well drained by an inch layer of crocks at the bottom, and must be clean. If they are dirty, the mould may stick to them when the cuttings are turned out for transplanting, and the tender new root fibres may be torn.

Making the Compost. A good compost for striking the cuttings of most plants can be made by mixing equal quantities of leaf-mould and well-sieved loam, and by adding to this two-thirds of sharp silver sand, and then sieving the whole through a quarter-inch mesh. It is always well to sprinkle the surface of the soil which is to receive the cuttings with a layer of sharp silver sand about half-an-inch thick, so that when the dibble is pressed down to form the hole for the cutting, some of the sand will trickle into it and be ready to encourage the production of roots. The sand keeps the soil porous and prevents the base of the cutting from rotting.

The soil should be firmed down and the slips inserted at least one and a half inches apart; they must not be placed too close together or they may "damp-off." Press the earth well down round the cuttings, as they will not root if standing loosely in the soil. If the cuttings can be fairly easily pulled from the compost, it may be taken as an indication that they are not planted sufficiently firmly.

Inserting the Slips. As has been said, cuttings strike more readily when placed at the side of a pot, than when inserted in its centre. Of ordinary plants about seven cuttings can be placed in a four-inch pot. No cutting should be set too deeply but, as in the case of seeds, the depth will depend mainly on the size of the cutting; a good general rule is to set about two-thirds of the length of hard-wooded cuttings in the soil, with soft-wooded cuttings only one-third or one-half should be inserted. Leaves should not be permitted to touch the soil; if they do, they will "damp-off." Water well after insertion.

When using pots or boxes, it is better, but not necessary, to sink these nearly to their brims in ashes or coconut fibre, which will keep the soil at an even temperature. Whether the cuttings are covered by plates of glass, glass bells or the fights of a frame, the condensation must be wiped off each morning. Once the cuttings have struck, ventilation must be given whenever possible, and decaying leaves should be removed to avoid any possibility of "damping-off." The great thing is to keep the soil at an even temperature.

GRAFTING AZALEAS: Preparing the Stock Holding the Graft in position

Preparing the Scion The Graft bound with Raffia

Too much light, air, water, heat, or cold are alike injurious to cuttings freshly inserted under glass. A close, equable temperature and a moderate degree of moisture should be maintained until the cuttings have "rooted." This condition is best attained by covering them with a bell-glass or hand-light and by shading them if not placed in a shady situation. Once they have struck, which will be in about three weeks, the cuttings should be gradually given more ventilation and hardened-off until they can be potted up singly for the greenhouse, or planted out in the desired situation in the open.

Soft-wooded cuttings soon form roots, and can often be potted-off in a month or so's time; cuttings of hard-wooded shrubs, however, take root less quickly and should not be disturbed for at least a year (sometimes eighteen months) after being struck. To give these cuttings ample room to grow, they are usually planted at least six inches from each other in rows ten inches to a foot apart.

Propagation By Layers

This is an easy and very sure method of propagation, usually effected about July, though it may be carried out at any season of the year. It consists in the production of roots on one or more of the lower shoots of the plant to be reproduced. An upward cut, just below a joint, is made in the layer or shoot; the incision passes from the underside through to the centre of the shoot, and is from about one inch to three inches in length, according to the size and nature of the plant to be propagated. The aim is to produce a "tongue" of bark and wood that can be wedged open and pegged down into the soil; the more the tongue is kept open when placed in contact with the earth, the better the chance of rooting.

The shoots which are chosen for layering must be perfectly healthy, and should be semi-matured. It is usual to layer several shoots at a time, and when the cuts have been made, as described above, the earth all round the plant is stirred up to a depth of three inches and the layers are pegged down firmly, so that the open tongues come well in contact with the soil. Little mounds of earth some two to four inches high are then piled up over the layers, which are pressed firmly down into the earth, and well watered. An addition of sharp silver sand to the soil (often in the proportion of fifty per cent, of its volume), as in the case of cuttings, helps the layers to root. The outer end of the shoot, beyond the cut, should be turned upwards to check the flow of the sap, and all buds not required to form shoots in the new plant should be removed. When the layers have rooted firmly, they may be cut away from the parent plant, potted up or planted out, preferably in the autumn.

The layers of most soft-wooded plants will be found to root in six weeks or so; shrubs like the veronica will take two or three months to form roots; while with hard-wooded shrubs, like the daphne or rhododendron, it will be a year or more before the layers are ready to be severed from the parent plant.

Propagation By Runners

This is, perhaps, the most simple method of propagation, though only possible with certain plants, namely those that throw out long thin stems or runners which grow out over the surface of the ground. At intervals along these stems will be found joints, and wherever one of these joints comes in contact with the soil and so remains for some time, roots form and foliage is thrown up.

To assist in this method of propagation, the earth should be stirred up to a depth of two or three inches all round the plant and the runners must be firmly pegged down into it, at the required number of joints. Young roots will form and after a few weeks they will be strong enough to support the new plant which may be cut away from its parent, and potted up or transplanted.

A better method, but one entailing a little more work, is to sink to their rims pots of good sandy soil exactly under the joints of the runners and to peg the latter down firmly to the soil in the pots. This operation provides an easier way of transplanting and one that is beneficial to the young plant, as the roots are not then so easily injured when replanting.

Propagation By Offsets

Offsets afford yet another means of propagation suitable to many herbaceous perennials and to many alpines. These offsets are growths forming young crowns round the older central crown, and may be carefully separated from the parent crown, when large enough, and can be potted up into small pots or transplanted.

About a month after the plant has flowered will be found to be the best time to accomplish this operation.

Propagation By Division

Alpines are best divided in July and August, or in March and April; the former time in the case of spring and early summer bloomers, and autumn flowerers at the latter period. The clumps should be lifted with their roots as entire as possible, that is, with a good "ball" of earth round the fibres.

This is done by inserting two forks vertically downwards, one on either side of the plant and backs facing each other, and then by levering the clump and its roots gently upwards. When the plant has been lifted, don't, as is so often done, use a spade to cut the roots apart, but carefully divide the plant up into as many crowns as possible by means of a sharp knife, which will do the minimum injury to the roots. The strong new outer crowns are those that should be retained and replanted, the old inner roots being discarded. The stems that have already borne flowers should be cut away from the new crowns, so that only the young and vigorous shoots from the base remain. These should be replanted as soon as possible, or should be potted up in a compost of half turfy loam, a quarter sand, and a quarter leaf-mould.

Propagation By Root-Cuttings

This is another and easy method of propagation, eminently suitable in the case of plants with fleshy roots. If the roots are examined in the late autumn or early spring, they will be found to be covered with small, whitish knobs or shoots; these are the "eyes" from which the new growth will spring.

Cuttings of these fleshy roots from two to eight inches in length, in accordance with the size of the plant, and each having an "eye", are taken. They are planted just below the surface and a few inches apart in light, sandy soil in partial shade, or in a frame with a warm, close atmosphere. The cuttings are inserted vertically with that part of the root which was nearest the stem uppermost.

In propagating plants whose roots are fleshy, but rather more fibrous in nature, the larger root-stems should be cut away from the crowns with as many of the smaller fibrous roots as possible adhering, and should be planted as advised above, but should be left intact and not be cut up into small pieces.

In the case of plants whose roots creep horizontally just below the surface of the soil, cut the roots into pieces from one to six inches in length, each piece having an "eye" or bud from which shoots can spring, and plant horizontally in the soil at the same depth as they were before being dug up.

The root-cuttings will require frequent watering during the following few months, and will be benefited by the occasional application of a little weak manure water. It is essential to keep the surface of the soil loose. The cuttings can be planted out in the autumn or in the following March or April.

Propagation by leaf-cuttings is a very interesting method, not often resorted to, and then only in the case of plants with succulent or thick, spongy leaves, and soft veins. A good healthy leaf is taken and planted stalk downwards in a propagating case in a compost made up of equal parts of sandy loam and leaf-mould well mixed together. The whole leaf is then pinned firmly underside-down, so that it cannot move, on to the mould in the propagating case (temperature 60 F.), and is allowed plenty of moisture, though the bed must be well drained and not be permitted to become stagnant, or the leaves will rot. In a short time little plants will grow. These can be transplanted or potted up as soon as they have roots strong enough to support them. This method of propagation, which may be resorted to at any season when fully-matured leaves are available, is particularly suitable in the case of such plants as Ramonda pyrenaica, Ramonda Nathaliae, etc.

Ringing

Hard-wooded plants which are difficult to propagate by other methods may be increased by a process known as ringing, and which consists in removing a small narrow ring of bark all round the stem in the place in which the formation of roots is desired. Care must be taken not to cut deeply into the stem indeed, it is better to peel off the outer bark only, and not to cut into the inner wood at all; no hindrance is then offered to the ascent of the sap. A callus is formed on the bark which forms the upper edge of the ring, and this thickens as time goes on, and ultimately, on contact with the soil, emits roots. Branches and trailing stems operated on in this way should be firmly pegged down, and earth should be drawn over the incision. Layers should be brought into as erect a position as possible, and they may be shortened back.

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