Helping roses survive floods

The weather seems set to make fools of us all. Last month I wrote about roses and drought, how to make water go further. This month it is about how to help roses survive the floods. These extremes must surely be the effects of climate change. Fortunately, roses are tough and can withstand almost any weather.

The main task is to protect the leaves from the fungus disease, black spot. If the leaves are not functioning, the roots can’t do their job either. With no sun and almost continuous rain for the past week, the conditions are perfect for black spot spores to infect the leaves.

The best protection is to spray with Chronos, the moment there is a break in the rain. Because Chronos penetrates the leaf, sealing it from the inside as well as the outside, it will not wash off if the rain comes down an hour or two later. Besides preventing the spores from entering the leaves, it also has a curative action for already infected leaves. The effect of Chronos generally lasts for up to a month, but under these conditions it may be safer to spray every two weeks because the disease load will be more intense.

Once the rain stops and the sun comes out, roses that were suffering from a lack of water will grow strongly, but if the leaves fall off from black spot, all the benefit of the deep soaking rain will be lost. Because rain is predicted for most of December, gardeners who will be going away on holiday are advised to spray with Chronos just before leaving.

Another task that can be done between thunderstorms is to fertilise with Vigorosa. By now the fertiliser that was applied in November or earlier would have been washed down, through the soil. The roots will love this but at the same time the nutrients further up need to be replenished. Sprinkle 30g (a single measuring cup) of fertiliser around the base of each rose.

If the fertiliser gets onto the leaves brush or wash it off. Because the ground is so wet, it should not be necessary to water after applying the fertiliser, especially if more rain is expected. Roses don’t like to stand in water. Where drainage is poor and the garden is water-logged, dig some channels to allow the water to run away. If the garden is very flat, all one can do is wait for the water to subside. If the topsoil has been washed away, wait until the rains stop and the soil dries out a little before adding topsoil mixed with organic material.

Be careful not to bury the rose too deeply in the new soil. The bud union, which is the thickened section at the base of the bush, should be just under the surface. Should the rains suddenly stop, and the high temperatures return, without further rain, the roses may wilt quickly, even though the soil seems moist. That is because they have become used to receiving so much water.

To acclimatise them to less water, keep on watering the roses but gradually reduce the amount of water so that they adjust naturally to once or twice a week of deep watering. Join Ludwig for a free walk and talk among the roses at Ludwig’s Rose Farm on Monday from 9am. Wear comfortable walking shoes, a hat and maybe bring an umbrella.

For more information contact Ludwig’s Roses at 012-544-0144. The rose farm is just off the N1 North, take the Wallmansthal offramp and follow the signs.

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