It might. Limiting the root system affects the plant's well being including its resistance to disease. Nutrients are also limited in a pot unless one fertilises often so you have two complimentary things working against the rose. Pots on or very near hardscape and in all day sun do tend to provide a hellish environment when temps are high. Deep freezing temps tend to affect plants in pots much worse than roses in the ground.

Choose smaller roses (than GT or GC, for example), use a water retaining potting 'soil' (ideally a 50-50 mix of peat based substrata and garden soil) unless you have a problem with too much rain in the rainy season in which case you should choose a slightly lighter mix, fertilise often, do not try to use 'organic' fertilisers like manure, and water until you get plenty of runoff to remove salt residue. Whatever you do, in a few years the rose will need repotting and a bit of root pruning. That's my 2cents worth of advice based on my experience in a climate very different than yours.

It is definitely a more challenging environment for the roots in a
pot and it is also difficult to maintain an even soil moisture. Often it
either gets too wet or too dry, resulting in water stressed plants. I
have much more problems with powdery mildew in particular when roses are
grown in pots compared to full ground, but it also depends a lot on the
varieties.

Many Austins are unfortunately quite susceptible to
mildew so you may be more succesful with different varieties. Use light
coloured pots to avoid it getting too hot for the roots in the sun.

I've had similar problems. I've noticed the smaller and more flimsy the pot, the bigger the problems. Heat and drying out are the biggest challenges to roses in pots here. The more heat stressed they are, the more the rose slugs bother them. I don't get blackspot, but powdery mildew runs rampant, especially in some of my potted roses. Sheltering the actual pot from the sun, while still letting the foliage get sun has helped. Here's photo of a potted tree rose that the rose slugs have devoured. My other rose of the same variety, in a huge container that is sheltered by other plants, looks far better.

I often see the same sort of thing with powdery mildew. I just don't happen to have a handy example of that, the way I do with the bug problem. This is an extreme case, due to my own negligence. I DEFINITELY notice that potted roses CAN be more prone to diseases and insect damage. The severity depends on the rose, the conditions/climate, the pot size, the potting medium, and the pot position.

Lisa I have nearly opposite weather issues but similar results. My pots are nearly always too wet the last couple of years (I have a potted lavender that's just about given up) but mildew, blackspot and insects go for those roses especially.

Thanks Nik and Henrik. I do think the soil moisture, nutrients and shifting temps make it a challenging environment. I've seen gorgeous potted roses on this forum so I was really hoping I'd just had poor luck. Especially since I've been toying with the idea of getting a truly gigantic pot and putting Zeph in it permenantly since I have hardscape right up to the house where I want it to climb. Maybe even building a sort of stone planting box about 3' x 2'?

All of what's been said above, plus the material the pot is made of. Terra cotta and ceramic are cooking utensils. They heat up quickly, retain the heat for a long time and radiate it that entire time into the soil ball, cooking the roots and boiling the water out of the soil. Water stressed roses are significantly more disease prone than those with cooler, damper roots. I will not grow roses in ceramic or terra cotta pots. Give me plain old black plastic nursery cans any day. They aren't pretty, but they work.

Hmm. At first I thought about the terra cotta thing and just felt like it couldn't possibly be hot enough. The current temp (granted at 2am) is 59 and the high tomorrow is 81. Those are very average for this summer (I hate to say 'for our area' because it's been unpredictable year to year my entire adult life) and the pot in question is not in an unrelenting sun all the time kind of spot. Morning sun tapering by 1-2 pm.

Then again when we do get a couple of days in the 90s and maybe even a colder patch it probably does stress the potted plants.

I always wonder when people say they pot up bands instead of putting them straight in the ground because that would be the surest road to pests and middling growth for me.

PS-I'll be honest that I prefer terra cotta for aesthetic reasons. It suits the English look that our house already has and is easy to find in many shapes and sizes so it's easy to create a kind of Great Dixter-esque look with groups of pots of different shapes and sizes.

I have found an initial growth boost when bands start in pots in the short term. After a few months they can be planted in the ground in the Fall. I think long term pot culture would not be as happy a situation here.

One good thing about POROUS terracotta pots is that when they are watered they are cooled down quickly due to the evaporation effect (that's physics..). Things, as always, are complex..

New young roses I always pot up before planting in my adverse soil conditions..

Terra cotta takes moisture out of the soil. So if you have the one terracotta pot that causes problems, and other plastic pots, that don't, that's the problem. That pot may need watering more than the others.

I's also recommend trying out water crystals.

Or the pot sealants which prevent the terra cotta from sucking the water from the soil (and prevent the "cooling" from the water percolating through the porous sides) but that goes back to the initial issue of heat cooking the soil and damaging or killing the roots. If you resort to the water crystals, watch the drainage or it can easily remain far too wet.

This is all very interesting. All of my (many) pots are porous terra cotta. I have spent a lot of time in CA though I've never lived there and I can also think of other places within the continental US where terra cotta might bake the plants or contribute to drying. In my case drying is good. Here at the tail end of July mine are so wet that moss grows on the sides and I sometimes have to bail standing water from the saucers. They are currently filled with a 50/50 compost and soil mix. I tried the water retaining potting soil once in window boxes and the plants rotted. From a purely

oops. Was going to add that off the top of my head I prefer tc in my situation because it does breath a bit more than plastic.

Stressed plants attract insects, nutrient deficiencies present in leached potting soils favor fungal attacks that may not occur - to the same extent, at least - when same kinds of roses are fully supplied with soil minerals.

You can't have evaporative cooling unless the water can evaporate. Which just doesn't happen in eastern humidity.

Pots shouldn't have saucers when it is raining.

I've heard a lot of bad things about the water retaining potting soil. I've never used it. I use the straight water crystals mixed in. Not only do they reduce watering, but they also can absorb excess water if it has been raining incessantly.

Now from my point of view, the biggest issue with keeping roses in terracotta is wintering. Roses should go dormant over the winter, and to do that they need to be exposed to temperatures cold enough to freeze and crack terracotta. One of my big AHA! moments in gardening was realizing that the inevitable instructions to bring plants inside when freezing was predicted had absolutely nothing to do with the hardiness of the plant. What was being protected was the pot.

Climate is the big differentiator. I have never had problems with too much water in rose pots even in the rainiest and coolest of seasons over here, even with the densest of potting mixes. Terracotta pots or plastic. A light mix over here means twice a day watering during the hot and dry season.

The above is true for roses but not necessarily for some other plants.

Well the upshot of this thread is that the underwhelming rose was put in the ground and replaced with this happy combo which will likely show no signs of stress (In younger, less responsible years I've dig heuchera and left it to its wits on top of the soil through the winter)

I have some 3- or 4-year roses stuck in pots. They definitely struggle more and look much worse than those that went in the ground 2 or 3 years ago, and they definitely get much more attention from the rose slugs and other pests. Any warming that the pots may provide is probably a good thing in my climate, as it's rarely warm enough in my little microclimate. They also haven't gotten their planting mix refreshed as much as they should have and are no doubt suffering because of that. But the mix is fast draining so at least I'm pretty certain roots aren't rotting. I really must get them into the ground to save them or at least pot them up. : (

Cassandra, I agree terra cotta pots look nice but do agree that, in general, they are not for roses. However, if large and receive afternoon shade - you may be just fine. I grow The Fairy in a large stone planter in full sun and I think the only reason it tolerates this is it drapes and covers most of the planter.

I am concerned about your soil mixture. I would only use 100% potting soil. This is likely why your soil stays too moist. I've grown roses in pots for several years and have experimented with different soil mixtures and found that soil mixtures, even with perlite, compost, etc compact too quickly, stay too wet and rose roots have difficulty growing through it and do not thrive. Oh, and I agree to remove the water basins and do suggest something is often needed to elevate the pot a bit so the holes do not become plugged (deck savers, etc)

I like growing most of my roses in large 15-20 gallon plastic pots and they do fine for me, even during the summer heat. I do find that most varieties are not as disease resistant in pots but they're so enjoyable to grow in pots I think it's worth it :)