I say myth. I've done this many times without any adverse affect.

It probably depends on your location. My understanding is that in some places, especially in Europe (UK, for example) this is definitely an issue. In my current garden in Maryland, as well as in CT where I used to garden before, this is not an issue. I always plant roses right away in the same spot where the other rose was growing and never saw any negative impact, even if the first rose was in this spot 12+ years.
Olga
Olga

As Olga stated, in Europe they use a rootstock that does cause problems with a new rose planted in the same hole.

Lance

I've always replanted in the same soil. If Weeks lets 75% of its expensive California farmland lie fallow, that's astonishing. Has anyone heard of other commercial growers doing that?

There is no scientific basis for the "secreted chemical" theory. However, in some northern European soils, they've found a buildup of a harmful nematode and a harmful fungus in old rose soil. Something similar has been found with apples in some PNW soils. Nothing for roses in the US as far as I know. It's not impossible, but there's no sense in changing soil unless a strong, persistent pattern should develop. Even so I would get a soil test first and get the County Agent to send a root sample to the state lab..

The link below is through Google Scholar to juried papers on Replant Disease in the Roseaceae which includes apples, cherries, etc.
A glance through the titles will dispell the 'myth' possibility.
As noted above, it may not be a problem in North America, but we've shared so many diseases across the Atlantic, we can't be sure that it's not out there, lurking.

http://scholar.google.com/scholar?as_q=Rosaceae&num=10&btnG=Search+Scholar&as_epq=replant+disease&as_oq=&as_eq=&as_occt=any&as_sauthors=&as_publication=&as_ylo=&as_yhi=&as_allsubj=all&hl=en&lr=

Here is a link that might be useful: Roseaceae and Replant Disease

See the link below for a review.
-------------------------------
There is some evidence that rose roots do give off a growth inhibitor.

Title: Growth inhibitor accumulates in the nutrient solution of closed system rose cultivation.

Author: Sato, N.

Authors affiliation: Shizuoka Agricultural Experiment Station, 678-1 Tomioka, Shizuoka, Iwata, Japan.

Published in: Acta Horticulturae (2005), 697(Proceedings of the International Symposium on Soilless Culture and Hydroponics, 2004), pages 511-516.

Abstract: "The circulating soln. was collected and analyzed for its nutrient concn. Three types of solns. were prepd. for the bioassay. One was the circulating nutrients soln. Activated charcoal was added to second soln. The third soln. was prepd. to the analyzed formula of nutrients soln. using distd. water. The rooted cuttings of rose were planted in each soln. and incubated in the growth chamber. The rate of change of fresh wt. before and after the incubation was biggest for the prepd. soln., which does not include the circulating soln. The fresh wt. growth rate was smallest for the circulating soln., and the results for the activated charcoal treatment was between them. Since the activated charcoal does not have a sterilization effect, it is possible that the growth inhibitors accumulated in the soln. during the circulating cultivation of roses. "

Here is a link that might be useful: rose replant review

Thanks, Henry. I withdraw my sentence to the contrary. However, closed system hydroponics would be a different situation from soil with even moderate drainage.

Something that might be a factor in reports of soil sickness might be the tendency of so many rose gardeners to overfertilize. Phosphate, potassium, chloride from KCL, and magnesium from epsom salts will build up in retentive soils. A buildup of these elements can cause salt problems or a deficiency of other nutrients in the plant, for example with phosphate tying up iron, copper, and zinc in insoluble compounds.