Black spot has made an early appearance. This annoying disease has defoliated some roses already but this can be overcome if drastic action is taken.
If you find some of your roses have lost all the leaves, cut the stems down to about a foot, pick up all the dead leaves and apply some Vitax Q4 fertiliser and fork this into the top of the soil and water afterwards, then give each rose a teaspoonful of Epsom salts.
In about two weeks, new growth will form and the leaves will be free of the black spot.
To keep control of diseases the roses need to be sprayed every fortnight with a fungicide.
The trouble is that this job is a nuisance and we tend to put it off. This is understandable as there are so many things that need to be done at this time of year but determination is essential.
It is a fact that pests and diseases become immune to the chemicals in the products we buy but we can overcome this problem by using a selection of different sprays.
Try this, it will work if the products are used every two weeks.
Week one: spray the roses and the soil with Roseclear 3.
Week three: spray the roses and the soil with Bordeaux mixture. This product is sold in small drums, is a powder and has to be added to water. It is an old fashioned fungicide but is still very effective.
Week five: spray the roses and the soil with Multirose – this is a well-known product and will kill pests as well as diseases.
Week seven: go back to Roseclear 3 and repeat this programme all through the summer and you will be free of diseases and you will deserve to be!
I was delighted to hear on Radio Solent that the roses at Mottisfont use this programme and they use Maxicrop all purpose feed in every spray.
Blackfly and greenfly (also named aphids) are also rampant this year, not only on roses but on broad beans and runner beans too.
There are quite a few natural predators such as ladybirds, lacewing flies and bluetits but an insecticide may be considered. Derris has been withdrawn but there are environmentally friendly replacements.
Please read the instructions on the pack and always spray late in the evening when the sun has gone off the plants.
At that time the bees and hoverflies have gone from the garden and only the pests and disease will be controlled.