11 November 2020

Many gardening tips and tricks are repeated every single year – but some are ill-advised

Contrary to common guidance, there are dangers to taking cuttings of redcurrants, blackcurrants and gooseberries now.

(Photo By Marcus Doyle/millennium images, UK)

I am not a gambling man. In truth, I must be one of the few folk who doesn’t know how to buy a lottery ticket. Nonetheless, I permitted myself a small personal wager recently and it has just borne me the satisfaction of coming good, although I am none the richer for it. My bet was that a gardening correspondent somewhere would fill their column inches this autumn with something along the lines of, “Now is the time to take cuttings of redcurrants, blackcurrants, gooseberries…and this is how to do it.”

Sadly, not only was the suggestion unoriginal, it was also ill-advised and, like so many repeated facts of this type, can be traced back to gardening books in the early years of the century.

Technically, there is nothing wrong with taking currant bush cuttings now. Indeed, nurserymen up and down the land are doing it, so should gardeners not follow suit? No, I do not think they should, and I believe this is an operation that could usefully be expunged from the gardening literature to everyone’s advantage. For while the cuttings will probably root satisfactorily, they will give rise to plants that merely perpetuate their parents’ contamination with virus.

I realise readers must be sick of hearing about viruses this year but, like taxes, I am afraid they are always with us – especially in our gardens. Virus contamination in soft fruit plants especially is extremely widespread and is sometimes manifest in symptoms such as mottled or distorted leaves, but equally commonly, it is all but invisible.

Unfortunately, it’s only the visual symptoms that may be elusive – although the leaf patterning on mosaic virus-affected raspberries is clear enough. It is the insidious weakening of the entire plant that causes the trouble and (were I a gambling man) I would bet that more than 90 per cent of blackcurrant bushes in gardens are yielding less than their potential because of virus contamination in their tissues, only apparent when someone comments: “The crop wasn’t as good this year.” For it is a particular feature of viruses that they permeate almost the entire body of the plant. They are thus inevitably picked up by any creature (such as an aphid) that feeds on the sap, and are also inevitably transferred to a plant’s offspring when cuttings are taken.

Nurserymen propagate from stock plants that have been raised carefully from original “starter” plants, which have, in turn, carefully been rid of virus contamination; a complex operation and not something gardeners can do for themselves. Yet, once these plants are grown in our gardens, virus-carrying aphids or other insects will fly, or perhaps mites will crawl, to re-infect them and, quite possibly, virus-carrying eelworms will wriggle through the soil to do the same. So ubiquitous are soft fruit viruses that, after a few years, almost all blackcurrants will be contaminated with a problem called reversion, all raspberries with mosaic disease, and other types of soft fruit with comparable problems.

So while I agree this is the time to be thinking about replanting your fruit cage, it is with new, certified stock from your garden centre that you should be concerned, and not with enfeebled cuttings from already enfeebled parental plants. That really would be a gamble not worth taking.

Next week: Nina Caplan on drink