i wouldn't think there would be much difference in fiberglass versus foam pots, it's probably the rose. i'm not saying it's a bad rose but probably needs time to get settled. imho the best pot material is clay pots. they keep the roots cooler, are porous so they breathe better. they are cheaper, the downside being they need to be watered more often and they can break with a frost.

It wouldn't surprise me if heat on the roots were an issue. I can't grow good looking roses in pots to save my life in my garden with high summer heat. In Mildew Valley, where the summers are cool, the potted roses are better....for a year or two at the most. Most of my roses grow too large to handle pot life with grace. The ones that did best were on a west facing patio with a short 3.5 foot wall that edged the patio. The roses sat up against that wall and thus were shaded all day long.

All of my roses are in the large 20" plastic pots. You may want to check to make sure the pot is draining correctly especially with all of the rain we have been having. After reading some great info on the Container Garden Forum, I added wicks to my pots to help pull any excess water out of the bottom of the pots and that seems to help.

I have three roses in polyethylene pots. I do not know how similar this is to fiberglass, but my roses are doing just fine. I live about 15 miles north of San Francisco and we have had hot weather lately--up to 100 degrees. I make sure they have water every day when the temps get up to the 90's and Ducher is never out of bloom. They are sitting on cement on my back patio.

I am a big fan of the foam pots, but would agree that poor drainage is the first place I would look for the rose doing poorly. I think the foam ones insulate for extremes better. I previously had winter die back to the roots with some roses, and this no longer happened once I switched. I assume it works the other way with heat.

I've grown roses in big, BIG pots, but like Berndoodle, I find that in the end,
they need to go into the ground.
I did find that smooth plastic pots were good.
Fiberglass pots with a rough interior surface can be trouble, down the road,
when it is time to remove them from the pot.
I have not used the thicker-walled foam pots, but I think the insulation could
be beneficial, though the rough surface issue remains.

Jeri

I've always liked the foam pots for their insulating value, they do deteriorate however from UV exposure and banging about. That said I have some that have lasted many years. I was all up on the durability and lightness of fiberglass but now I'm thinking they are just OK. I do think they tranfer the heat to the roots, even the double walled ones. I have three huge fiberglass pots that used to harbor Marie Pavie, Marie Daly and SDLM. All three are now in the ground and doing much better. The only rose left in one of those pots is Clotilde Soupert and I guess I didn't transplant her because I'm not sure I like her all that much. Maybe I'm hoping she'll perish. Three years is the max on keeping roses in pots in my experience. Two is better.

For my part, I've exiled all my potted roses, maybe a dozen or more, from the deck to the driveway for evaluation. They all got hit with rose slugs this spring and are just coming back. Most of them were first year experiments, teas mostly, that I was trying to grow on and evaluate for their first summer and winter. Instead of sending them to the pot ghetto I decided to dress them up in pretty pots and let them live on the deck. I used clay, fiberglass, plastic and foam. I think I like clay the best, but it is heavy and you have to protect it from freezes.

I don't think I'll garden with roses in pots anymore, I've given most of the pots over to other plants like veggies, herbs and annuals. I have one hydrangea and one Japanese maple in pots but they are sort of like my bonsai experiments.

Three years is the max on keeping roses in pots in my experience. Two is better.

*** I'd say that matches our experience.

I should add -- because of our extreme (and I do mean extreme) gopher problem,
many of our roses are in very big squats sunk into the ground.
It works.
With enough holes in the pots, roots do get out.
Though real mature growth is usually delayed until that happens.

But though we have good reasons for doing it, I do not think it is ideal.
In our experience, roses will always do better with their feet firmly stuck into the ground.
And if a rose is "replaceable," we incline to plant 'em, and let 'em take their chance.

Jeri

Thanks for mentioning the virtue of smooth plastic when the time comes (which it will, you tell me!) to get the rose OUT. I have two very large smooth pots available, a very light colored plastic (about 15 gal). I have the tiniest of lots here and never intended to have a pot ghetto...BUT here I am with Martha Gonzales, Sweet Chariot, Marie Pavie, and Tamora in pots. My only location for Marie is a west-facing bed full of crepe myrtle roots; I'll probably attempt to cut the pot off her and put her in the ground this fall. She seems vigorous enough to manage down there. Hope I can keep the others happy until we make our move south...3 years from now! Thanks, all, for your help.

I agree with len511 in that I prefer terra-cotta clay pots.

I have two very large, very beautiful, and fairly expensive fiberglass containers. Unfortunately, the roses I've grown in them have never really been happy.

The roses I've grown in the foam-type and plastic containers have done a little better, but I have to be careful to not over-water in those types. In those types of container its easy to have dry soil on the top and completely saturated soil at the bottom. The roses I've grown in them seem to have more blackspot than normal. And foam doesn't seem to age well for me.

Every rose I've grown in true clay terra-cotta has been happy.
You have to water a little more.
You can't leave out in freezing weather.
They are heavy.
But my roses sure seem to like 'em.
I'm convinced there are benefits in their ability to allow roots to "breath".
I don't blame the roses, I wouldn't want my feet perpetually wrapped in plastic either.

Randy

Randy, if I ever quit moving my roses around I think terra-cotta would be a great option for me. Currently I put whoever is in full flush in front of the bay window. Currently Tamora is "covering" for Prairie Harvest while it rests. Sweet Chariot is taking a looong rest-- I should never have put TWO in that pot. It's good to know that clay works even in the extreme heat of north Texas as I wasn't even considering clay as an alternative.

barbarag I've got you beat by one! I have 3 Sweet Chariots in one pot, a cream glazed clay pot, and this will be their last year in it. I also used to put my roses in bloom in front of our bay window in the breakfast/sunroom. Now that the roses are gone I've put window boxes of pink wave petunias and white geraniums there so I have something to look out on while I have my morning coffee. Mundane perhaps, but all I do is water and I have color all season.

Recently, a friend and professional landscape gardener asked me if I wanted a pot of daylilies she didn't want to tend anymore. I said "Sure!" I never turn down free plants. She's getting rid of all her deck plants, "downsizing" as it were, to simplify her life. I'm sort of doing the same, but only was able to reduce my pot number by about half. What I didn't know was that I wasn't getting a gallon pot of daylilies, I was getting a half a whiskey barrel full of daylilies! So now I have to find homes for the daylilies - and give her back the barrel before I find a use for it. Which brings me to that question. Have you grown roses in whiskey barrels? Hmmmm, maybe I won't give it back!

Linrose, I had to smile at your "white geraniums". That is a plant that I have really fallen for over the last couple of years, and especially in white, or white with touches of deep pink. Not just nice blooms, but really nice, large leaves. In one protected area of my garden, they even grow as perennials after mild winters here! That was a surprise.

Randy

Whiskey barrels--haven't tried 'em, but the size & shape seem ideal for roses-- lots of diameter without excess depth. I would think they would drain well with appropriate holes drilled int he bottom. Saw some on sale here but they were absolutely falling apart; the wood was so dried out the metal hoops were falling off. No thanx on those!

Barb -- DON'T GO THERE.

The problem with those barrels is that, by the time the rose begins to mature,
the barrel begins to deteriorate.
At one point, we had many of them.
Over the years, we've dealt with one collapse after another, sometimes
using stackable blocks around the barrel, then carefully pulling the
decaying boards out from around and under a rose.
If barrels tempt you, use them for geraniums, or pansies, or ANYTHING
other than long-lived roses!

Jeri

I have half a dozen or so roses in 20-inch clay pots. They do reasonably well in them. Clay pots need more water in high heat situations, although mulching the tops helps. I also have all my pots up on trivets to keep from staining the patio underneath, so contact heat from the paving is not an issue, and drainage is excellent.

However, potting soil is after all artificial soil. We use it in pots for its lightness and drainage, but ultimately it is not intended to sustain plant life indefinitely. It is mostly peat and sand with some fertilizer added and a pH neutralizer, or if organic, with some organic amendments. When they run out, you are left with peat and sand. You might be able to extend the life of the potting soil by adding lots of compost. I don't know if a study has been done on that or not. Most gardeners who are keeping plants in pots long term either make frequent use of dilute synthetic fertilizer or repot regularly with fresh soil.

The point of all this is, if the rose has been potted for a while, it is possible that the problem is exhausted soil rather than the pot. Could still be the pot, though.