Help! Yellow spots on leaves!

I’m doing my first outdoor grow, and have been keeping my plants in a greenhouse. Yesterday I opened the flaps and let them get some sun and breeze — and today I see this! Is it fungus? What can I do? I have some Draconil fungicide spray; is that too dangerous?

Pollen?

There’s a ton of pollen around here right now, but this doesn’t brush off.

I forgot to mention that they’re growing in Happy Frog, if soil could be a factor.

I’d scope the underside of the leaf for mites or since its older leaves could have been overwatered earlier. Not like any fingus i’ve seen.

Kerowacked said:

I’d scope the underside of the leaf for mites or since its older leaves could have been overwatered earlier. Not like any fingus i’ve seen.

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I checked for bugs and didn’t see any, but would it hurt to give the plants a light spritz of Ortho bug spray? I have some because I use it on my roses.

I did water the plants yesterday, with regular tap water, which is what I’ve been using all along. I water every 3-4 days, as needed. The only thing I did differently yesterday was opening the greenhouse.

littlebat said:

I checked for bugs and didn’t see any, but would it hurt to give the plants a light spritz of Ortho bug spray? I have some because I use it on my roses.

I did water the plants yesterday, with regular tap water, which is what I’ve been using all along. I water every 3-4 days, as needed. The only thing I did differently yesterday was opening the greenhouse.

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Tap water is usually high pH to prevent corrosion. You can add a couple drops lemon juice per quart to lower that. I only use neem and spinosad on weed, can’t help you with ortho but you don’t smoke roses.

Kerowacked said:

Tap water is usually high pH to prevent corrosion. You can add a couple drops lemon juice per quart to lower that. I only use neem and spinosad on weed, can’t help you with ortho but you don’t smoke roses.

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Oh, I didn’t want to use it; I was just freaking out and it was the only thing I had. I’m usually all-organic except for roses, but I thought spraying them would be better than letting them die if it truly was an emergency.

Not a fungus, possibly a deficiency Maybe overwatering but my bets on deficiency if you don’t have a moisture meter then get one. I’d give them some dolomite or shoot them up with 1 -2 ml per gallon of cal mag.

I’d say it was just a coincidence it happened during environmental changes

thisbuds4u101 said:

Not a fungus, possibly a deficiency Maybe overwatering but my bets on deficiency if you don’t have a moisture meter then get one. I’d give them some dolomite or shoot them up with 1 -2 ml per gallon of cal mag.

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Thank you. I just ordered some Cal-Mag and a moisture meter!

I wouldn't rule out fungus just yet. Do your roses also get these spots? Septoria transfers really easily from roses.

sirtalis said:

I wouldn't rule out fungus just yet. Do your roses also get these spots? Septoria transfers really easily from roses.

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Last year my roses had black spot, so this year, I’ve been spraying them with fungicide weekly. So far they seem to be fine. They haven’t ever gotten light spots, though.

Baking soda and water mix use in spray bottle works great.

Hmm, re-reading the first message and these spots showed up in one day? First time getting direct sun could be light burn.

Overwatering will do that. You can see it before it happens the leaves get a bubbly/soft looking spot where those white spots show up. Could be something else like if you dripped something on them as well.

littlebat said:

Last year my roses had black spot, so this year, I’ve been spraying them with fungicide weekly. So far they seem to be fine. They haven’t ever gotten light spots, though.

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Black spot gets in the soil from dropping leaves, i do roses too. Its aphid season.

Roy O'Bannon said:

Overwatering will do that. You can see it before it happens the leaves get a bubbly/soft looking spot where those white spots show up. Could be something else like if you dripped something on them as well.

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They've been in the greenhouse and we've been getting a lot of rain, so there's moisture inside that's been dripping on them. I didn't even think about that! I really hope that's all it is. They look the same today, with no further damage.

Kerowacked said:

Black spot gets in the soil from dropping leaves, i do roses too. Its aphid season.

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Black spot is the devil. I learned last year that you just can't do roses without chemical pesticides and fungicides (or at least I can't).

Update: they're fine today. No new spots. Yay! I have the greenhouse flaps open again, and I'm going to water again in the morning (I've been watering every 3-4 days). I'll keep you posted if new problems appear. Thanks for your help!