Rose rust: a thorny problem to tackle

Rampant rambler - the rose New Dawn.
Rampant rambler - the rose New Dawn.
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Goodness me, you do seem to enjoy growing roses and at our allotment society store I’ve seen several people buying Epsom salts and rose fertilisers.

At the garden centre there were readers with the list of products suggested to control most of the diseases we see on roses.

Just to recap: copper fungicide followed a fortnight later with Multirose and a fortnight later by Roseclear 2 or 3, then start the regime again. This will ensure pests and diseases will not become immune to the chemicals, but please read the instructions before buying these products.

It’s always best to prevent problems, so, if you have not sprayed your roses yet, now is the time to prevent black spot and mildew. A pump-up pressure sprayer is a good investment because concentrates can be bought which work out cheaper than those in ready-to-spray containers which are OK at the beginning but stop working before the container is empty.

In the past 10 years there have been serious outbreaks of another disease – rose rust. This is the right name because it covers both surfaces of rose leaves with a rust-coloured powder.

The same disease appears on fuchsias, but each type of rust only attacks that species. For example, hollyhock rust won’t affect fuchsias or roses. The interesting thing is that while they only attack that particular species it’s the weather which causes the problem to be severe. Hot, humid weather allows the rust to spread rapidly. If you see it on your hollyhocks, spray the roses quickly!

When I was an apprentice we used liver of sulphur which looks like hard, light green putty. This was hit with a hammer until it turned to a powder and 4oz added to two gallons of water to prevent rust. It worked brilliantly but liver of sulphur, like many other products, has been withdrawn.

So what do we use now? The best product by far is Systhane. Read the instructions before you buy and spray now and repeat according to the recommendation so rust will not ruin your roses.

Chris West, of North End, Portsmouth, prompted me to write about rose rust, but he also wants to know how and when to prune and train a rambling rose called New Dawn – a very old, perfumed, light pink, rampant rose.

The main thick stems are best tied into wires fixed 10 inches apart in hoop shapes so the tips of the main branches are facing the round. This induces young shoots to grow out of the main stems and during the summer the rose flowers come in great bunches.

Once the flowers die, the flowering stems are cut off so new stems form.

These can be left to grow or, better still, tied down to form trailers or tied in to form the letter C. It’s worth doing this because the flowers are stunning when well-trained... and they’re easy to spray too.

TIP OF THE WEEK

When pinching out the side shoots on tomato plants, do you find your fingers are smothered in green strong-smelling sap?
If you wash your hands in COLD water with plenty of soap the green will wash away easily and your fingers and cracks in the hands won’t be black.