Sorry for posting twice!!!

That depends a whole lot on where you're located and your planting practices. Most grafted roses Zone 5 and above are often planted with the graft BELOW ground surface for better winter protection....so the answer is moot there. If you're in the southern United States and commonly plant with the graft above the ground, I guess I can't give you any personal experience but I'd guess it doesn't matter. I'll listen to others on that point though.

In Florida the main benefit of grafting on Fortuniana stock is to defeat the southern root-knot nematode. Therefore the graft should be exposed to prevent the scion variety from forming roots that the nematodes would destroy.

Elsewhere the graft may be exposed if it is safe from freeze damage (I would say zone 8 is safe for typical modern roses). Or it may be covered by mulch or soil. It is best to keep the level fairly stable. Temporary deep mulching for purposes of winter protection can cause canker disease in some climates (e.g. eastern U. S. zone 5-7) with some varieties.

I've always heard that you should keep the mulch away from the actual base of the rose during the growing season. Winterizing is a whole other subject though.

Good point, Seil. I can't speak to winter protection because here, that consists of making sure they remain watered if there is no rain and watching for wind damage. I know they had a lot of canker issues in the San Jose Heritage Garden a while back and blamed it on too deep wood chip mulch burying the crowns of the plants. The mulch remained too wet and there were serious losses. I've not used wood chips as rose mulch, but my more traditional horse manure and planting mix mulches have never remained that wet in my climate, so I've not experienced the canker issues. What I have experienced is the elimination of new basal activity by buring the crowns of the bushes under too deep mulch. I've found by not getting the mulch close to the unions or crowns, my plants have regenerated themselves more successfully. I don't know how much of that is varietal or climate related, it's just what I've experienced here. Kim

I don't mulch at all myself. I've never cared for it. But there was a recent thread, I believe, about burying the grafts doing exactly what you experienced, Kim, few, if any, basal canes coming up.

I don't bury my grafts either. I'm in zone 6 so it has not been a great problem for me as far as wintering. Some years, if I have the energy, I protect but a lot of years they're on their own. Either way they seem to do just about the same. I like to be able to see the graft and keep an eye on it. For what, other than new shoots, I don't know but it's just how I feel about it.

Perhaps I'm mistaken, Containerfreak, but based on your first question on this topic (in your "another quick question deadheading" thread), it seems to me that you're asking for guidance on how thick a layer of mulch you should lay around your roses to preserve soil moisture during Louisiana summers.

If that's the case, the goal in laying mulch is to reduce evaporation brought on by the heat of long hours of direct sunlight on the soil, and, to a lesser degree, by winds. I'd recommend that you lay only enough mulch to accomplish that goal.

There are many kinds of mulch, and we've no idea what you're planning to use; nor do we know how far above soil level you've planted the graft unions. As a general rule of thumb, I'd say that for a summer mulch in the South, a three inch layer (slightly more or slightly less) is adequate. I keep the mulch away from the base of the plant by several inches unless I'm using pine straw. Pine straw I apply more thickly and am unconcerned with how close it is to the base. Hope that helps, & sorry if I've misconstrued your question.

I am in Minn., have mostly Hybrid Teas and have my unions all over the place, some are four inches above the mulch some are near ground level.

For mulch either cocoa bean hulls or Eucalyptus work very, very well avoiding disease.
I like the cocoa bean hulls as they can be bone dry on top and very moist where they hit the ground, and they smell nice.
I pulled purslane from them a few days ago, and it was like kneeling on a soft mattress.

I try to make sure the area around the lower unions is clear of dead leave etc. and soak the area with Serenade.
This year, the one rose I have that has what could be called a buried union, as it is below ground level but sitting in a bowl is doing very well, disease free but even in the heat my high unions are doing very well also

I use shredded pine bark and pile it up toward the center and the outside, leaving a depressed drip ring about 3 ft in diameter around the center. It's typically 3-6 inches high in the center and outside circle, completely covering the entire circle area of the rose. I usually make at least two applications a season.

I've never had the mulch cause/induce/contribute to canker or cane rotting - far from it - and I've been doing it this way for well over 10 years for 80+ roses. Maybe other types of mulch are different, but IMHO, shredded pine bark contributes almost as much to a rose's health as alfalfa. There's just something about the pine smell or the breakdown products that roses seem to love.

All my bud unions are buried, by the way, and I try to use the mulch to bury larger unions that form at the cane vertices in the center. All of this promotes own-rooting by the rose you're trying to keep instead of Dr. Huey (all of mine are Dr. Huey grafts).

I meant to add that lots of Mills Magic Mix keeps the basals popping up, regardless of the mulch depth.

Thanks everyone for the information!!! I am trying to mulch to protect the roses as they try to get established in this hot weather!! And I also have heavy clay soil that I have done some amending... I have 3 roses that I planted last year 1 that is doing great the other 2 are surviving.. This year I added 9 more so I will be having a lot of questions!!! I know that it is going to be an uphill battle to get them established but I am learning a lot from everyone on this forum!!! Thanks again.