Have you ever wondered why some people’s roses appear to do better than others’? It may have absolutely nothing to do with the regular fertiliser regime, the amount of water, how you prune them, whether you summer prune them and so on. It may be purely the fact that they are on different rootstocks.In former gardens I always grew roses. My mother loved them and I went through a phase of constantly sourcing different roses to grow. My preference was for the old fashioned varieties; in the later gardens these roses were always grown on Rosa multiflora rootstock. As a person who usually researches most things that interest me, rose culture was no different. And by reading books by respected gardeners found out why this rootstock would work best for me.
Rose sickness, from my own personal experience, is a problem that rose purchasers should be aware, especially with roses purchased on Doctor Hughie rootstock. They tend to sucker profusely once stressed, are prone to rose sickness, are more disease affected and appear to need regular amounts of water in order to stop them suckering. They almost demand a clay sub-soil but roses on Rosa multiflora rootstock are not fussy about their soil – they seem to manage where-ever they are planted, as long as they are kept moist until fully settled in. Once settled, they don’t look back.
Rose sickness, according to Christopher Lloyd, is more correctly called “Specific Replant Disease”. In his wonderful book, “The Well-Tempered Garden”, 1970: p239, Lloyd refers to the “mysterious soil-borne disease whose existence has been known for over 200 years but whose causal agents have yet to be identified”. He identifies this disease as what we know as rose sickness. He also makes mention of the fact that Rosa multiflora rootstock is resistant. Considering that this was pretty common knowledge over 40 years ago, why then do we still have rose growers using Doctor Hughie rootstock?
Lloyd, in his book “The Well Chosen Garden”, 1984: p15 discusses the issue of pests and disease amongst roses. He states “It should be remembered that the greater the field numbers of density of any single crop or creature, the greater the field day for parasites and disease organisms to which they are a prey”. He also goes on to state that “the greater the variety of plants that you grow, the fewer will be your problems”.
Christopher Lloyd, now deceased, was a remarkable English gardening identity. I went to a talk that he gave many years ago now when he visited South Australia and was instantly attracted to his witty, charismatic charm. He was immensely knowledgeable on the subject of gardening, realising especially the need to fit your choice of plant to the type of soil within your garden. I found his wisdom to be quite inspirational; he was elderly at the time and had had many years of hands-on gardening experience.
Rose gardens, where roses predominate, are a monoculture and are more prone to fungal problems and disease. When roses are grown amongst other shrubbery in borders, reminiscent of English style gardens, the incidence of disease and pests is considerably reduced. Small birds and natural predators also inhabit gardens of greater plant diversity, and it is these creatures that keep aphids and other pests at bay, especially when no toxic chemicals are used. Gardens of greater plant diversity encourage biodiversity in all its forms – this is why a real garden is such a healthy place – a haven for all manner of diverse species that work within this ecological microclimate.
I have also found that many roses grow very well when struck as cuttings, with no grafting. Selecting vigorous varieties is the safest measure, because they will strike better. Grouping one colour range is the safest, and often the most aesthetically pleasing – far more so than one of yellow, one of red, one of pink and so on. You often see bright pink roses with gaudy yellow which I personally don’t like. Bright pink with pale yellow or cream and conversely pale pink with gold work well together, but it is often safest to keep these colours apart if in doubt.
As a sustainable advocate, I choose to use roses on multiflora rootstock because I don’t have the need to keep spraying for fungal problems and I also never spray to eradicate aphis – I let nature take care of itself without human interference. They also need far less water through the drier months with the ‘deep and infrequent’ method of application. And of course these roses don’t sucker, the most influential reason I have for choosing this rootstock.