Growing Roses Indoors

It is usually during the winter that many people buy or receive as presents flowering house plants such as cyclamen and azaleas, which give a gorgeous display of colour for perhaps two months, looked after carefully. When these plants fade, their owners wonder what they should buy to take their place. It is always possible to acquire another azalea, but even that will only last a few more weeks. Perhaps roses are the best plants to follow on. It is not always appreciated how easily these popular plants will grow in containers both indoors and out of doors. In some ways they are more beautiful than ever if grown in a greenhouse or in the house, particularly when compared with roses in the open garden, because their blooms are completely unblemished by the ravages of pests and diseases and the effects of bad weather. Greenfly can generally be kept at bay by spraying with clean water, caterpillars can be easily picked off by hand, black spot seldom seems to attack roses grown under cover, and rust never. The only possibility is that the roses might be affected by mildew, which can be dealt with by spraying with a commercial fungicide.

If the roses are to bloom in spring, a start must be made in early autumn. There are quite a number of both floribunda and hybrid tea roses that respond quite well to this treatment. In fact, it might be said that almost every variety is satisfactory. So there is no real problem of selection. There are two approaches. The first is to buy a bare root plant from a nursery and, after trimming away any unruly roots, to plant it in an eight-inch pot in John Innes Compost N0.4, to which has been added a small quantity of John Innes Base Fertilizer, both of which are fairly easily obtained from garden supply shops or through mail ordering. If a clay pot is used, a one-inch layer of crocks should be placed at the bottom to assist drainage, which is not necessary in the case of plastic pots. The soil should be tamped down and filled to about an inch from the rim to allow space for watering. The alternative is to go to a garden centre and select a container-grown rose, which has a root ball of such a size that it will fit comfortably into an eight-inch pot. Any space around the outside should be filled with John Innes compost so that the soil is fairly tight. After planting, it should be well watered. It is then allowed to stand outside for about a month, when it should be brought indoors.

Provided the soil is moist, little more has to be done until mid-winter. If it is not, it should be moderately watered. At this time the rose should be pruned. This is done by first removing all the dead, weak and diseased shoots and any that are growing towards the centre. After this the remaining shoots are hard pruned, that is, cut back to an outgrowing bud, which is the second or third from its base. Incidentally, at the same time every year, potted roses should be similarly treated.

During the next few months, temperature control is important. When producing roses in pots, it is a good idea to be guided as far as possible by the rules laid down by the growers who raise them in greenhouses, which is to keep them at a temperature which is equivalent to that outdoors two months ahead in time. This might be regarded as 50°F (io°C) by day and 46°F (8°C) by night towards the end of winter; 6o°F (i5°C) and 50°F (io°C) respectively in early spring, and 65°F (i8°C) and 55°F (i3°C) respectively later in spring. While it might not be possible to adhere strictly to these levels in a house, where there are no strict controls as there are in a greenhouse, to get the best results an endeavour should be made to do so. What it really amounts to is that it is necessary to move the rose from a cooler to a warmer spot as the weeks pass by. Remember that no roses want to be molly-coddled but it is important to see that they are kept in a well-lit place, where there are no draughts, although ventilation from a slightly open window on days when it is not extremely cold, is welcomed by them.

Late in spring, the most perfect blooms will appear. Apart from their decorative value, flower arrangers appreciate them very much, because they can impart an unusual, out of season look to their arrangements.

When they have ceased blooming, all the dead flowers should be removed and the pots put outside in semi-shade in early summer. Here they can remain until autumn, with little attention other than watering if the soil becomes very dry, and having any flower buds removed as they form. Each pot should then be dressed by replacing the top inch of soil with a commercial potting compost plus a little base fertilizer. At the beginning of winter, the pots are brought indoors again to prepare themselves for another gorgeous display in the following spring.

Regarding varieties, the following hybrid tea roses are proved because they are grown for the florist trade: 'blue' 'Sterling Silver', apricot-yellow 'Dr Verhage', red and gold 'Katherine Pechtold', red 'Montezuma' and vermilion 'Baccara'. Already beloved of British flower arrangers there is also pinky peach, 'Sweet Promise', ('Sonia', as it is called on the Continent). Among the floribunda roses, that are very attractive when grown indoors, are 'Lilac Charm', yellow 'Allgold', 'Copper Delight', carmine-pink 'Paddy McGredy' and crimson 'Red Wonder', but perhaps the most superb of all are the 'Garnette' roses, which can be obtained in a range of the loveliest colours, and are characterized by the long-lasting powers of their blooms, both when on the bush and in water.