Towards the end of April it may be necessary with bush roses to do a certain amount of dis-shooting, the aim being to remove young growths that look as if they are going to overcrowd the centre of the tree. These can easily be pinched out with the thumb and forefinger. It is seldom necessary to rub out more than three or four shoots per bush.
If in April it is found that the top bud or buds of any growths that have been pruned back refuse to break, cut these shoots back further still to just above an upward growing eye that obviously is not blind or dead.
Keep the beds hoed regularly to prevent any weeds de-veloping; hoeing should start in the spring and continue till the autumn.
The placing of medium grade sedge peat or compost on the surface of the ground all over the beds is known as mulching. This is done for the purpose of (1) keeping the roots cool, (2) of controlling the weeds, (3) to control the disease black spot by preventing the spores blowing up from the soil, and (4) in order to supply organic matter to the ground.
To ensure large size blooms, disbud. At the ends of the young growths will usually be found one terminal bud and two or three side buds. The side flower buds are pinched out when quite young and this gives the terminal or central but the whole of the manufactured food being pumped up into that shoot. This work is done with bush roses, principally with H.T.’s and does not apply to Polyanthas or other types.
With bush roses also, and to a certain extent with standards and half-standards, look out for suckers growing up from the stock. The suckers have quite a different appearance from the rest of the growth on the bushes or trees. The leaves are usually smaller and there are more thorns or spines. Often on the sucker these spines or thorns are smaller, darker and less hooked. Cut out the suckers immediately they are seen, at their point of origin from the roots. This will prevent them growing again.
Directly the blooms fade on bush roses and on standards and ramblers cut back the growths carrying the dead flowers. If this is done after the first blooming in June in the case of H.T.’s the second blooming usually takes place in September. Don’t cut the growths back harder than 150 or 175 mm (6 or 7 in) or you may encourage basal buds to break into growth and these will be killed by the frost during winter months.
In the spring and summer spray with Liquid Derris if necessary to kill insects. You cannot control a bad aphis attack with one spraying. Ladybirds however can. Diseases like Mildew and Black Spot may be controlled by spraying with Karathane and Captan.* Encourage ladybirds as these eat the aphides (as do the larvae of the ladybirds they are like tiny little alligators!).
Mulches of properly made compost contain antibiotics and as a result attacks of fungus diseases are rare.
Though roses will withstand the long droughts, the disease called Mildew is particularly bad on plants that are suffering from lack of water. When watering has to be done it should be by the hose and an overhead whirling sprinkler. This should be left in position for at least half an hour at each spot so that a good wetting with artificial rain will be given .
In the autumn, rake up the prunings, fallen leaves, etc., and put them on the compost heap to rot down with other vegetable matter collected. Use an activator on the heap, and the heat engendered will kill the disease spores and insect eggs.
Go over the supports of standard rose, ramblers, etc., each winter and see that they are firm in the ground. Undo all ties, loosen strips of felt if necessary and re-tie afterwards. See that the tarred string is never allowed to cut into the bark.
