Old rose bed syndrome, companion planting & allelopathy

I thought I'd start a new topic on this rather than just post a reply! Old rose bed syndrome is something I'm going to experiment with. Last week I removed a rose plant where the scion and died and the graft had grown - I didn't know what the stock was. The plant had apparently been in the ground for at least 40 yrs according to the previous house owners, and it wasn't in very good condition; and, I took out Paul's Scarlet Climber that was very weak. Also I don't know the stock.
Old rose bed syndrome is also referred to as allelopathy. Simply defined, it is where plants produce inhibitory or toxic chemicals. It is also the basis for companion planting. There are those people who are very knowledgeable about companion planting but don't know why. Tomatoes and basil grow well together, but tomatoes and cabbages or any of the brassicas don't. Plants will use what are called chemical antagonists to inhibit the growth of other species so they have the competitive edge. And, some plants allow others to be planted near them - companion planting. It is a fascinating subject.
If there's a note on the rose cultivar not to plant it in an old rose bed, I suspect it depends on the root stock. I'm of the opinion that some root stocks will be ok together, and some won't. But of course, we're not told that when we buy a new rose, and at the moment I've got no way of testing this, and I don't know how to find out what the stock is.
So I will buy a climbing rose and plant it about 30 cms away from where the old roses were removed. I'll condition the soil but I won't remove it. I'll see if any on the old rose roots remain, remove those, and see what happens.

This is almost correct... alleopathy is due to the chemical inhibition of plants and their seeds from chemicals released by certain plants. There is no evidence to show that roses of any species are alleopathic (studies have been done on this to determine this.. I will find my references an post them here later when I have a little more time). A good example of alleopathy is the Camphor Laurel. When the leaves drop to the ground they release chemicals into the ground which prevent other plants form growing under them, effectively reducing competition for water. The crux of old rose bed syndrome is said to be due to the accumulation of nematodes and other such pathogens in the ground which older roses may acquire a certain amount of resistance to over time due to repeated or sustained exposure. Newly planted roses do not have these acquired defences and so are more suceptible to these pathogens. Companion planting may well be due to the beneficial combinations of various chemicals exuded from the plants, however, this is not an example of alleopathy unless one is detrimentally affected. The primary reason rootstocks do not all perform equally is that different rootstocks prefer different soil conditions. For example Dr Phooey is a terrible rose here because it does not like acidic soil. My soil is acidic. Multiflora, on the other hand, loves acidic soils. Most nurseries here in Australia graft onto Dr Phooey so when they arrive here and do poorly I like to regraft them onto multiflora understocks to see if that improves things at all... it often does. 'Furtuniana' likes sandy soil and is resistant to nematodes. So understocks is no a one-size-fits-all thing but I'm sorry to infomr you that it has nothing to do with alleopathy.

The topic of the old rose bed myth busters is based on the above premise that old rose beds accumalate pathogens and I want to know whether, with modern cultural practices, it is as big a problem as it might have been when the myth was first born. I suspect it has, as Oz mention, more to do with depletion of nutrients over time than it does with anything else and that proper conditioning of the soil prior to replanting might solve a lot of the pressumed problems. I've been growing roses for near 30 years and can't say that I have ever seen old rose bed syndrome and think maybe it is a symptom of outdated cultural practices of bare earth, chemical fertiliser regimes and monocultures and nothing else. When due care is taken to maintain good ecologicalconditions around roses, as with any plant, many of these 'problems' become obsolete.

Simon, that's very interesting. Thanks for that. Allelopathy is now becoming a separate science, I believe. I don't know if roses release phenolic &/or turpenoid compounds.
Also, how do you find out what the stock is?

You usually can assume it is Dr Huey in most places... some places are using multiflora, some (only one I knew of) uses Manetti, the ones from WA will usually be on Fortuniana. If they came from Treloars or Ross Roses they use Dr Huey. Otherwise you'd have to cut the top part off to tell what it is

As much as the Doc make a great show, only blooms once

If in doubt about rootstock I would email the above rose nursuries to get the answer. Not the front desk but the gardeners themselves. That is IMO the way to go.

I have read a book about the Meilland family with references to rootstock during the Second World War. They used almost anything they could find
around the country side but favoured climbers as they are easier to strike.
Probably almost any climber or species rose could be used as rootstock for they are compatible, just a matter of how easy they strike and what soil they like.

I have used unknown climbers, Dr Huey and Multiflora but the latter is preferred and now used exclusively. How well these do in old rose beds I don't know but could be a worthwhile experiment for someone with more time to spare than myself. Can also think of a lot more exciting things to do with roses.

Hi guys, very interesting reading. So with a youngish garden, it wouldn't hurt replanting where a new rose hasn't made it ?
Bruce, is the book you read, "for Love of a Rose " ? Great book, hey ?

It depends why it didn't make it I guess Karen... I'm paranoid about RMV (I know... I am as shocked as everyone ), so I don't like replanting where an RMV plant was incase roots are left that can cause root grafts etc... I try to dig out as many roots as I can... don't see any reason why not to replant in other cases personally.

Yes, its amazing what roots get left behind.

Hi Karen, good to see you posting again, hope the Kelpies are still upper most in your mind.

Yes!!! That's the book, would appear they were doing it tough in France at that time. Then the German invasion on top of the difficult economy.

The rose cuttings ( Peace ) that left France on the last American plane out went to the right people. A portion of sales were banked for the Meilland Family and after the war they were able to build a new glass house and continue rose breeding with the proceeds.

Quite a heart wrenching story, they must have been very dedicated and have rose sap running in their veins.

Most roses can grow on their own roots. They're not sugar princesses.

But, some rootstock is generally better than other, that's true too (I swear by Fortuniana. I know of a Melbourne nursery switching to Fortuniana completely). However, most important is how sick or healthy was the rootstock before grafting, and the mother plant, and what was the quality of graft. We're talking about living things here, that vary in their health, vigour etc.

In today's modern gardens, filled with quality soil and a myriad of fertilisers -- all according to the modern Gospels of Roses -- the true problem is the economy of scale: nurseries don't make good quality grafts, they don't check rootstock thoroughly, they release plants too early. It's the money issue. When we buy those roses, we overfeed them, or don't feed them enough, overwater them, or don't give enough water. Few of us know how to prune them, how to spread them, tie, support them, plant accompanying beneficial herbs, recognise what a rose really needs and when, understand climate variation, etc.

When you go through this checklist, it's a wonder we have any rose thriving as advertised. But we have them, and that's a credit to a remarkable, adaptable, sturdy, living plant we all love. If it doesn't succeed, don't blame it, for it's hardly its fault.

As a rule I try not to buy 1st year release stock and wait for feed back from others of how it does perform, sometimes it it a case of must have, however I try to tell myself a rose if shovel pruned is cheaper to replace that a new of these new fang dangles bloody energy light globes than dont last any longer anyway So if it dies I should not really worry

The sad truth is, however, that there are a lot of the more modern roses that do not grow well (at all) on their own roots. Dave was telling us some time baclk that hydroponically grown glasshouse roses were grown own root because the supply of nutrients was far greater and more consistent allowing even poor root systems to function efficiently and some varieties are next to impossible to strike. So, whilst many can, and do, grow well on their own roots a lot just won't.

I wish more did, hence when non prose growers are me for cuttings I say NO go and buy grafted stock as I wont waste time on getting them going