Gardening: Brian Kidd's rose-saving regime

Nice drop of rain we had the other day. I bet Portsmouth Water was pleased.I was too, because our lawn had been fed and as soon as the feeding was complete, it hissed down for about 30 minutes and one water butt was filled half way.

Saturday, 27th June 2020, 6:00 am
A rose with blackspot.

If I controlled the weather it would only be allowed to rain at night as plants grow when it's dark.

Several queries about roses this week – black spot is back! This disease has defoliated some roses already but can be overcome if drastic action is taken.

If some roses have lost all leaves, cut the stems to a foot, pick up all dead leaves and apply Vitax Q4 fertiliser. Fork into the soil and water. Give each rose a teaspoon of Epsom salts. In a fortnight, new growth will form, minus blackspot on the leaves.

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To control diseases, roses must be sprayed each fortnight with fungicide. Trouble is, this job is a nuisance we put off which is understandable as there is so much to do. But determination is essential.

Yes, pests and diseases become immune to chemicals in products, but we can use different sprays. Try this; it will work if the products are used every two weeks.

Week one: Spray roses and the soil with Roseclear 2.

Week three: Spray roses and soil with Copper mixture. This comes in small, green plastic drums. It’s a powder and is added to water, an old-fashioned fungicide but still very effective. Use the strength recommended for copper deficiency.

Week five: Spray roses and the soil with Multirose, a well-known product which kills pests and diseases.

Week seven: Go back to Roseclear 2. Repeat this programme all through summer and you will be free of disease... and you will deserve to be!

Blackfly and greenfly (aphids) are also rampant – on roses and broad and runner beans. Why are there so many and how do they breed so quickly?

In the autumn they mate and females lay eggs low down on roses. In a warm spell in spring, the eggs hatch. All baby aphids are female and within days every female starts laying nine young ones every day for three weeks. Imagine the numbers produced from just one egg. But there were dozens of eggs laid in autumn so by midsummer there could be as many as 20,000 aphids and you are thinking, ‘yes, they’re all on my runner beans and roses!’.

There are natural predators like ladybirds, lacewing flies and blue tits, but an insecticide may be considered.

Derris has been withdrawn but Pyrethrum, made from chrysanthemum flowers, is environmentally friendly. Always spray late in the evening when the sun has gone. Bees and hoverflies will have gone and only pests and diseases will be controlled.

If you consider yourself to be green you can use soap flakes, one level teaspoon in a gallon of water late in the evening when the sun has set. Don't use washing up liquid. This is a harmful detergent which can scorch leaves.​​​​​​​

THIS WEEK’S TOP TIP

Cut back all side shoots on cherries, nectarines and peaches by half the length of the rapidly growing shoots. This will encourage flower buds on the parts you leave behind. These buds will form next year’s fruits.

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