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Diagnosing my minis - blackspot and?

Posted by gardenInTheSky none (My Page) on
Tue, Mar 12, 13 at 21:12

Hi, I have two minis with some problems. Mini # 1 (these leaves are both from the same plant) I'm pretty sure has blackspot (and powdery mildew), but I just wanted to verify. I have tried using molasses / baking soda / dishsoap, but I couldn't tell if it worked or not because my leaves would turn yellow and fall off a few days after application.

I also pulled off these leaves right after I took these pictures.

This post was edited by gardenInTheSky on Tue, Mar 12, 13 at 21:23


Follow-Up Postings:

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RE: Diagnosing my minis - blackspot and?

Mini #2 I must confess I am stumped by. It has slowly lost its leaves from the ground up after they turn yellow, although I have not over watered. The few new leaves it has had (they start out red) haven't really turned green either as they did last year. They're a green with dark-reddish blotches, as if they haven't finished maturing. There are tons of nubs where new leaves can sprout out all along the stems, but they haven't actually grown.

You can see from this pic that the yellow leaves are also curling on the edges, and they're also blotchily red.

This plant has been in the same pot since last year, and I thought perhaps the sickliness was caused by it becoming too crowded in its pot so I recently tried changing it to 5-1-1 mix and trimmed the roots by an inch or two. I've never done that before, so I was pretty nervous about killing it, + all the roots were healthy, there weren't any dead ones that I saw. Strangely, there didn't seem to be any difference in the health of the plant both before and after the re-potting.

Any ideas?


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RE: Diagnosing my minis - blackspot and?

In my garden, when I see a rose with the splotching pattern in the photo on the right, I immediately check my watering system. To me, it looks like water stress.

One of the first signs of water stress, is for a rose to drop their leaves. They are eliminating any plant part they can to survive. They will stop blooming and drop those leaves just to keep the roots alive.

Neither photo shows bs infections. Do a Google image search for both blackspot on roses and mildew on roses. Then because powderry mildew is a different rose disease, you might want to Google images for powdery mildew on roses.

Smiles,
Lyn


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RE: Diagnosing my minis - blackspot and?

Thanks! Relieved it's not blackspot after all on Mini #1. I didn't realize either that mildew and powdery mildew were two different things. I haven't been watering a lot, but that's because I'm afraid of over-watering because the pot doesn't drain very well. The leaves didn't feel droopy or anything so I didn't think it was water deprived. I'll look in to more mildew control I guess and carefully water a bit more.


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RE: Diagnosing my minis - blackspot and?

Water is the most important thing you can give your roses .... after good drainage. Your drainage problem is very easy to fix, but I suggest you just for it because you seem so concerned about your plants.

Change the potting soil to a good potting soil that drains the way you would like it to drain. If you are rushed trying to get everything done in your life finished yesterday and your climate is such that this works, use a commercially prepared and tested potting soil that holds the moisture longer than those that just let everything drip straight through.

The roses will only take up what they need. You don't want your soil to be too dry or too wet .. for long.

Just remember, you are growing your roses to add joy to your life. Don't make it a hard task and truly enjoy your roses.

Smiles,
Lyn


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RE: Diagnosing my minis - blackspot and?

Thank you for the advice Lyn! I guess I just worry because I have flashbacks to all the plants I killed when I was young and am trying to prove to myself that not everything under my care dies haha.

Any ideas about Mini #2?

This post was edited by gardenInTheSky on Mon, Mar 18, 13 at 21:35


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RE: Diagnosing my minis - blackspot and?

I really can't tell what's going on from the photo. It looks like you are growing the rose indoors. Few, if any, roses do well when they are grown indoors. It's the quality of the light. No, I can't explain it. It's just one of those rose things.

Yellow leaves are a sign of stress. It can be because of either over watering or under watering, poor drainage, not enough light, mite infestation, too much nitrogen in the food you are using, too little nitrogen and more.

I've killed plenty of plants, but I haven't killed any roses, yet. I should have because I made plenty of mistakes, but roses are tough.

When I first started growing roses, I had to grow them all in containers because I lived in a condo. One of the lessons I learned during those years is that the container should be large enough to grow a root mass that is almost the same size as the top growth of the plant because the root mass is generally the same size as the top growth. If the container is too small, that will also stress the plant ... you'll get those yellow leaves again. I made it a practice to generally plant the rose into a container a bit larger than I thought I needed.

Some roses just don't grow as well in containers, even minis, as they do in the ground. If the rose has a spreading top growth habit, the roots generally like to spread out, too.

The thing I loved about container gardening is that if a rose wasn't performing well, I could move the container so that it got different light, different air circulation, etc. Often just moving the container a few feet made all the difference in the world.

Also, I found that the general rule of thumb of watering the rose deeply the day before feeding the plant helped the plant take up the nutrients better when I fed it the next day. Time released food didn't seem to work as well as diluted liquid fertilizer.

I think you are approaching the care of your roses in the best way possible. You are learning from the rose. It's telling you that you need to make a change for it to thrive. So many people don't make that connection. Congratulations.

I am sending you a link to an article in the HMF Ezine archives about growing minis in containers. I hope it helps.

Smiles,
Lyn

Here is a link that might be useful: Basic Miniature Rose Care In Containers


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RE: Diagnosing my minis - blackspot and?

It looks like a phosphorus deficiency, in my opinion.
Try feeding it?

http://www.bhg.com/gardening/flowers/roses/solving-rose-nutrient-problems/

Here is a link that might be useful: rosecare.com - vitamin deficiencies


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RE: Diagnosing my minis - blackspot and?

Sorry for the very late reply, but thanks for the link intris! I will be bookmarking that page for future consultation. I went and got some liquid fertilizer and put a few drops in the watering can every day, and now I have a new shoot growing!


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RE: Diagnosing my minis - blackspot and?

One thing, make sure the pot is large enough for it. 5-7 gallon size would be ok. Minis have large roots.


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RE: Diagnosing my minis - blackspot and?

Currently they're potted in a 2.5 gal container, and I thought it'd be plenty big. Guess not. They look pretty tiny in proportion to their pot though. Would it suffer any damage if I left off re-potting into larger pots until next year?


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