Propagating equipment

cure. Roots will develop over a period of months, and when they can be seen through the polythene the newly rooted plant should be severed from the parent and potted.

grafting I his method is rarely used to propagate greenhouse plants, with the occasional exception of tomatoes. But since tomato growing is an important feature ot most home greenhouses, the method used for these plants deserves to he mentioned here. The value ot tomato grafting is that it enables the grower to graft selected varieties on to root stocks that have been bred specifically to resist various common root disorders. Seeds of the root-stock are sown 7 to lodays before those of the variety: the seeds of both should be well spaced out in their trays, 36 seeds per tray being about right.

Grafting should he done when the seedlings of both variety and root stock

I have explained that the conditions under which a new plant is raised can have a bearing on its long-term growth. For this reason you will find that good propagation equipment is a worth while investment.

Plants generally need a uniformly warm temperature during this period and prefer the heat to come from the bottom rather than from the top (whence the term 'bottom heat1). In the case of cuttings it is essential to reduce moisture loss from the leaves, and high air humidity 111 the immediate vicinity is the best way ot achieving this Seedlings and cuttings also require sunlight if they are to develop normally, and the once-common practice of covering cuttings with newspaper is today frowned upon by progressive gardeners.

All these conditions can be achieved by the use of a propagating frame. Its size will depend 011 the amount ot space available, and some simple calculations will be necessary to work out how many plants are likely to be at the propagating stage at peak times in the spring.

There are numerous makes of plant-propagating units. The bottom heat Usually comes from thermostatically controlled warming cables or plates of 40 to 75 watts output, so running costs will amount to only a few pence per week, The covers tor these units may be of light-gauge polythene sheeting, tit rigid plastic, or of glass: sufficient height is required to allow the inclusion of' small plants 111 pots. Some designs are bigger and more robust, in effect providing small greenhouses within the greenhouse. Most such models provide air heating as well as bottom heating by means of warming cables running around the interior walls; they enable relatively big plants to be housed within and can prove a great fuel saver to the enthusiastic amateur who does not want to heat the whole greenhouse.

It is essential to use purpose-made electrical connectors for all pi,Hit propagators, otherwise the moisture associated with propagation is likely to cause short-circuiting and consequent power failure.

are about the thickness of a pencil. An upward-sloping incision about 30 mm (il 111} long is made in die stem of the variety, while an identical but downward-sloping incision is made in the rootstoek stem, Then the 'tongue' formed by the incision in the variety stem is slipped into the incision in the rootstoek. and the union is bound with adhesive tape. The rootstoek is now ported, and the entire plant is placed in a polythene tent for three or four days to reduce loss of moisture through the leaves. The tape is removed as soon as variety and rootstoek are effectively growing as one plant. The portion of rootstoek stem above the point of union can be removed in due course,

Grafting selected lomjio variety 10 3 rootstoek 1 Makr* incisions in vanety and rootstoek stems 7 Bind the union with idheaivg tape, 3 Pol th<? rootetock 4 Enclose plant In polvttwn'* teni

Mist Propagation Unit

Above A pi up mating (rattie The soil warmirit) cables are boned 111 sand underlying 0 layer of compost Below Vist units keep the leaves ot cuttings maisl Some propagating harms include automatically metered nvsi units

Mist Propagation

Mist propagation units automatical!*, provide cuttings with the optimum conditions for rooting by keeping moisture on the leaves at all times; this prevents cuttings from wilting. The unit is open to allow maximum light to reach the plants. In addition to these advantages, the cuttings arc less susceptible to disease.

Propagation units of this type consist o) one or more mist nozzles, a detector which indicates when the leaves are almost dry. a solenoid valve to switch the water supply on and off automatically, and a filter. Most units have built-in or separate soil-warming equipment. Cuttings are inserted in the normal way, and will develop roots more quickly in these units than in a less sophisticated propagating case. Once rooted, the plants require some form o! 'weaning', and the more expensive mist propagators can be adjusted lor less frequent misting. This drier regime normally continues tor a few days, after which the plants are removed from the unit. The automatic system is designed to prevent the compost from becoming too wet; nevertheless the compost should be of a tree-draining type. Soil temperatures of 21 to 24 t: {71 to 77 F) are recommended. Incidentally, many amateur gardeners use such equipment for keeping established pot plants adequately watered during their absence, for instance over long weekends in the summer.

] have stressed the importance ot good light conditions on a number of occasions, and the greenhouse owner whose growing programme relies 011 a busy propagating period early 111 the year would do well to consider seriously some system ot providing supplementary lighting. At this time of relatively short days a period of dull weather can cause quite a setback to plants being propagated, and supplementary lighting will overcome this problem. Although expensive sodium or mercury lamps are used in commercial greenhouses, the amateur will find warm white or white fluorescent tubes quite satisfactory if they are suspended 4S0 to 600 mm (iK to 24 in) above the seedlings in the propagating area. 1 Ins additional light calls tor higher temperatures-of the order ot t(t C{fi 1 F) in the vicinity of the plants, but some of the additional heat w ill he provided by the lights themselves.

Above A pi up mating (rattie The soil warmirit) cables are boned 111 sand underlying 0 layer of compost Below Vist units keep the leaves ot cuttings maisl Some propagating harms include automatically metered nvsi units

Rooting Medium For Mist Propagation
Organic Gardeners Composting

Organic Gardeners Composting

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