How much fertilizer are you giving them, how often, and what kind?

In a grow bag, and we have been having 90 degree weather followed by a couple days of rain, followed by 90 degree weather...on repeat

Placed in the hole with initial planting

Once a week between rainstorms diluted per instructions

The lawn did get fertilized last week, these are about a foot off the grass

How large are your containers? And what is the growing medium?

The reason I ask is that it doesn't look like disease to me.

Possibilities:
1) Container could be too small

2. Too much water or a medium that is holding on to water too well
3. Growth medium could be compacted
   4) Too much fertilizer (seems unlikely from your info)

I'm not saying it's definitely not disease. It could be something bacterial (speck, canker) that is presenting a bit oddly. Maybe some other possibilities that I'm missing. It doesn't look like any septoria I've seen, but maybe someone else has seen different.

Is that photo representative of the damage, or did other leaves you trimmed off have more spots? And exactly how much rain have you been getting?

If it is dry, I water about every other day to every three days. Here is a link to the water data for the nearest HYDRA network station...finally moving into more consistent weather according to reports...crossing my fingers water levels will be more consistent.

HYDRA Rain Data

These are in smaller pots than I would like. I was accidentally sent 5, 5 gallon smart pots instead of 10 gallons...rather than having me send them back they let me keep them. I decided to use them for the determinate and dwarf varieties I grew this year. The rest of my plants are in at least 10 gallon pots or larger. The other Principe Borghese in the same size pot looks just fine.

They're in a potting mix from one of my local nurseries...the only things I remember since I no longer have the bags are that it was organic, specifically for containers, and had worm castings.

The leaf up top was the worst I could find in the bunch I took off...others were yellowed with the darker rim, but lacked the spots, and others were green with just the dark rim. I didn't notice it on Sunday, but did when I went out to water yesterday.

I haven't grown PB, but from what I understand, it gets to be a very large, vigorous plant. Has it started flowering/fruiting? Do you see any roots growing out of the bottom? Is there any kind of weird smell from the medium in the pot when you water?

Leaf edges going bad like that would make me suspect a root problem, i.e. rootbound, root rot from the medium holding water too well, etc. Maybe someone else will have some insight or a counterview, as that definitely doesn't look like septoria to me, and if it's one of the bacterial leaf spot diseases, it's not a typical presentation. Never hurts to prune and spray in the meantime, though.

As for the other plant, it could be behind in root development or just more resistant to stress for some reason. Even within varieties, there can be variation, as being the same variety doesn't mean that the plants are genetic clones.

It is my first year growing it...but it is a determinate and is supposed to be 3-4 feet tall max. I do have flower trusses, and a couple small green fruit.

Maybe I will hold off watering for a bit with this guy and see if he improves. The smart pots are supposed to help with aeration because they are cloth, but who knows. It is also my first year using them as well.

This is the one I stripped lots of leaves from

This is the one with no leaf damage, however, I did lose a main stem to the evil squirrels.

Oh, my bad. I have no idea where I got the impression it was a big plant. From the rolling on new growth and the pale color (although it's hard to get an accurate read on color through photos), it does look like the plants are under stress. Yeah, if they're in a grow bag, water should be draining well. Do you check moisture levels below the surface of the soil before watering? I usually check an inch or two (depending on container size) down in my containers before watering.

I'm pretty much stumped if it's not a root or nutrition problem. Hopefully someone else will know something. Meanwhile, it never hurts to spray and prune off bad foliage.

Two things I really stress when container gardening: 1. Frequent watering is a must...especially in hot weather 2. Fertilize every week or so...but use a dilute solution (maybe half strength or less). PS that does NOT look like septoria to me

I have had a hard time with leaf curl on all but my Sungold and my dwarf plants...hot hot hot weather and then rain have made keeping water levels consistent an issue. (Hence the Plant Nanny's...I don't know that they actually do much, but they do make me feel a little better) I usually stick my fingers down into the soil to check and see if it feels damp, but also go by plant tops being "wilty"...these two have had some of the most significant leaf roll, but the other one is significantly healthier looking so far.

I was thinking Septoria because of the rain possibly causing splash back on the leaves...the two PB's were ones I had not done a lot of trimming out of lower branches yet...just the very very bottom ones.

Only time will tell I suppose. I am going back out tonight after work to see if I need to pull more leaves and will give them a quick copper spray.

fireduck, that is true re: watering in heat. I've learned that sometimes the value of the water's cooling ability is just as important as the actual wetness, which is why a really well draining mix is key, too, so that things don't get waterlogged despite frequent watering.

Roots can sometimes really cook in a dark pot during the summer. Maybe try wrapping the outside of the pot in something white?

Crisping around the edge of the leave can be associated with over fertilization burn. JMO

Looks like fertilizer burning.

If you want to be really dialed in on your container potting mix moisture content...buy a moisture meter at your local nursery (or HD). They are pretty cheap...and they work really well. The probe gets right in the roots...which is where you want to target.

My initial thought was fertilizer burn also, but the regimen doesn't sound excessive. Although I haven't used it, I'm familiar with the Dr. Earth product, and it's not excessive with N. I believe it is somewhere around 4-6-3. Maybe the doses have been too high? Or maybe too much Jobe's in the planting hole to merit such frequent applications?

4-6-2.

The lawn did get fertilized last week, and this is the closest plant to the grass...I am wondering if maybe it got a dose of the lawn fert too...I'll hold off with water until tomorrow, and maybe hold of the fertilizer until next week. See if that helps.

Thanks for all the advice everyone! It certainly isn't an issue I have ever experienced before, so I much appreciate all the suggestions.