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Is this a lighting problem?

Posted by somethingtohide (My Page) on
Tue, Feb 17, 09 at 20:29

I'm growing sunflowers indoors, and starting a few others. They are the dwarf variety mainly and I'll give you some details of my setup so you can help.
Look at the picture:

If you want more, just go to

See on the newest leaves the bubbled up looking things?

Here's the deal. It's more brown in real life. It's more brown now because that picture is a day old. This one and one other flower have the same problem. The bumps are near the center of the leaves and close to the stem.

I want to know if this is from the lights or watering.

Could they be getting too hot? I've got a 4ft 40W 2 lamp fixture on them, color temp 6k on them and I've lined the inside of their home with aluminum foil and made reflectors of that too to keep a lot of light inside. The lamp doesn't get hot but maybe all that bouncing around is burning them? The lamp is maybe 7 inches from the plants.

Or is it watering? Am I over watering? I use a water bottle to water, I just poke a hole in the cap and squeeze. It used to do fine and I had precise control. But I read that after they start growing bigger sunflowers don't need as much water. Are they getting too much?

OR.. They've gotten kinda wide and still close to the soil so it's hard to water underneath them close to the stem. I usually end up getting a few drops of water on the plants themselves. They're small drops but compared to the plants they're huge. And the brown bubbled up spots are kinda where the water lands. I try to get the water off the plants in these cases but sometimes it's difficult, I don't want to hurt them.

What's your thoughts?

Follow-Up Postings:

RE: Is this a lighting problem?

The fluorescent tubes are too far from the plant; they are 7" and should be less than 3".

I didn't see the brown spots you're referring to. But assuming they are there, probably are caused by soil, nutrient, or pH problem. Or perhaps your tap water; what kind of water do you have and how do you treat it?

RE: Is this a lighting problem?

Well I can't move the tubes any closer to the plants right now because they're in a pretty deep container and the tubes can't go inside of it. The plants are slowly closing in on the lights though.

As far as the soil, nutrient, or pH. I don't think it could be that, could it? I'm using Miracle Grow Potting Soil.

And for water I'm using bottled water. Aquafina Purified water to be exact.

RE: Is this a lighting problem?

Can you stack books under the plants to raise them closer to the light?

Not really

It's not like I can't lower the light any more.

The soil doesn't reach the top of the pot.

The tubes are within 1 cm of the top of the pot. The soil fills about 3/4 of the pot, and there's about an 8 inch gap between the soil and the rim of the pot. The plants are about 3 inches tall now.

The only way to get the light closer is to cut off the sides of the pot to lower the lights in the missing groove I just cut.

I'm colorblind. So maybe the plants aren't brown. But they are bumped up where I showed you and they're glossier than the rest of the leaf, and a little darker.

I'm also using a CFL which I place inside the pot (the pot isn't really a pot, it's a tub). It runs pretty warm. It's also closest to the two plants with the symptoms. That's why I thought it was a lighting problem. I swapped it to the other side for now.

RE: Is this a lighting problem?

Fertilizer burn?

RE: Is this a lighting problem?

Maybe? Explain what that is please.

I don't use fertilizer. I didn't do anything to the soil other than pour it out the bag.


The link in this post is to a picture I just took. It's of the plant in question.

Here is a link that might be useful: Picture

RE: Is this a lighting problem?

Is there anything strange on the underside of the leaves?

RE: Is this a lighting problem?

I don't know. It kinda looks like ribs.

You see on the leaf closest to the camera how it's got the thick vein running through it's center?

It's like a few of those where it's bumpy on the top.

RE: Is this a lighting problem?

The National Sunflower Association has a list of the most common problems with sun flowers if you want to research it. A few mention blistering of the leaves.

Here is a link that might be useful: Common Sunflower Diseases

RE: Is this a lighting problem?

Maybe alternaria? That one is the only one that sounds like it might be it (it's caused by overly wet/humid/hot conditions, kinda what I've given it).

Thought it does say it'd be noticeable later on in the lifetime of the plant.

I'll keep my eyes on the plants though.

Do you think I should hold back on the watering because they're getting bigger?

Maybe let the soil dry out before watering again?

Right now, I water a little bit whenever the soil is almost dry. But not all the way dry.

RE: Is this a lighting problem?

I do not see anything at all brown on any of the photos, I went to both the links, and the ones posted on this page. They seem fine to me. As to what the bumps are, I really can't say, but I would not worry too much about it, it is most likely just your colour blindness.

I am by no means an expert however, but I am wondering why you are growing these indoors. Sunflowers require a lot of sun, and typically shoot up real nice and quick if directly sown in the spring. My neighbour was always jealous of mine, (direcly sown) and tried to grow her own. She babied them way way too much, planted them in pots, they always died.

Well, now they are planted, I say continue growing them, putting the CFL down with them is a good idea until they grow up. They seem healthy enough. Do you intend to put these outside? When?

As for the damping off problems you have been having, I had huge problems with this in the past. You get all excited to have a full tray of sprouts, put them to bed, dream of the wonderful flowers you will have come summer, wake up, and it looks like something pinched about 90% of them to death right at the soil surface overnight!! Heartbreaking! The good news is, there are things you can do to help prevent it. I have used a product called No-Damp with great sucess. Takes my typical loses of 90% down to about 1% to damp off. However, I have heard that sulfur or cinamon sprinkled on the soil surface when you plant the seeds can do the same thing. Also, Camomile tea is great for stoping Damp Off.


Thanks homemommy.

I was getting a little worried, true. :D

Though I was hoping for the best and just thinking that the bumps are something that's supposed to be there, cause I don't think all the leaves should be perfectly flat. Maybe it's a rigid structure.

As far as growing them indoors, it's a little early to start them indoors for transplanting here, I don't think our last frost is until the end of march or maybe even april. The ones I'm growing here are dwarf sunflowers, specifically for growing indoors (or small outdoor ones). Many people just grow them indoors too. They do need lots of light still though. I've also got some regular sunflowers that I plan on starting when it gets a little warmer. As far as directly sowing, how did you do it? Water them each day and made sure they weren't dry? And how long did it take to sprout?

And with the damping off, is there anything I can make sure to not do to keep it minimal? I had no problem with this before, and I assumed it was just with the Moss Roses because they actually don't take well to being watered a lot. I just thought since they were still sprouting they could use some. I'm trying another batch directly sown instead of germinating them first to see if anything will be different.

Again, thanks for your reply. =]

RE: Is this a lighting problem?

If they are indoor sunflowers that makes sense :-)

The only thing I can think is that if they are started now, they probably won't last all summer, but if you are starting more, then that is ok.

I think though, that your sunflowers look fine. I don't see any brown spots, and they don't look leggy.

As for things you can do to control damping off, well, the most effective thing I found, was a bottle of No Damp. It is not expensive, and easy to find around here. But, it smells awful and some people think it to be toxic, but how toxic is it really? I have a hard time believing that as wouldn't tiny little seedlings die if drowned in a toxic brew?

But, there are other things you can do.
1.) Use a sterile potting mix and tools while planting. You can buy sterile soil, or cook it in the oven first, should kill off most pathogens. I have also boiled soil and it has not given me any grief in my limited experiance. You can always sterilize tools by letting them sit in alcohol or boiling them.

2.) don't keep the seedlings overly wet. Don't use a humidity dome after they germinate. However, you will want to wean them off it, I let the seed sprout, then raise the lid a little over 3 days to wean them off it to the regular air.

3.) I have heard great things about Camomile tea, but never tried it myself, basically brew up some tea and use that as your seed starting water.

4.) Cinamon also I have heard can prevent damping off if sprinkled on the soil, or sulfur, available sometimes at nurseries.

The thing about damping off, is it happens with tiny seedlings, because I have read the actual germination process triggers the fungi in the soil! If you can get the plants through the first few weeks to a month, chances are the fungi even if it is present will leave them alone. For that reason, if treating the soil with any of the above methods, you want to make sure that it is done when the seeds are planted, and followed up on for the first few waterings. (although I typically use weaker and weaker solutions.)

On a couple occasions I was able to save seedlings that where in mortal danger of damping off because their sister seedlings where dying left and right, by using a very strong solution of No Damp. But, it is not prefered after the fact treatment, much better as a preventative.

I have found though, that some types of seed are much more prone to damping off. I have found that bachlor buttons, Zennias, and sweet william for example are very prone to it, while Dahlias, Marigolds, impatians and daisies / black eyed suzys are not. But, this is just my experiance. So, to me it could be that you are right in that the roses you where trying are much more prone to it.

RE: sunflowers.

As for growing sunflowers outside. I usually get a larger peat pot about 3" accross. Fill it with some potting mix, and place 3 seeds deep in the pot. Then, I plant the whole pot outside in the ground where i want it. I find this helps me with placement, and with keeping track of where they are before they sprout. Water well, and just keep an eye out that they don't dry completely out, but they are even from the start fairly drought tolerant plants. If they are in danger of being eaten, you may wish to place some mesh over them until they sprout. If the pot gets more then 1 sprout, you will need to kill the others (cut them off) after the strongest gets its first true leaves. Heartbreaking, but nessisary for good strong plants.

Another thing you may wish to do, is space your plants so that about a month - 6 weeks later you can plant more seed between your sunflowers. This way, you will get a couple bloom periods!! As one batch is starting to die off, the next are getting going!

RE: Is this a lighting problem?

Thank you again =]
My zinnia's have all done fine, with the exception of that one. But I think that was my fault. I should have helped him out. There was a thick piece of dirt (compared to the seedling) right where it was poking out and I thought it'd just move away. It kinda gave up.

I just saw the first other batch of Moss Roses sprouts. Very tiny. I've taken off the dome that keeps them humid because last time they all died with that. Hopefully this time it'll go swell =]

As for the No Damp. You think I can pick it up at the local Home Depot or Lowe's? Or maybe even a Pike's Nursery? It may come in handy later on.

I had another question, but I completely forgot it. It'll come to me later.

RE: Is this a lighting problem?

I buy my No damp at Home Depot and Lowes, although I have heard conflicting reports as to if it is available in the states.... (I am in Canada). If you want to go this way, I would get it soon, as once the fungus starts is attack and you notice it, it is usually very hard to recover from it, things go down hill very quick. Basically, have it ready for your next watering. If you can't find it at Lowes or Homedepot, then you should be able to find a good product that prevents damp off at a decent nursery.

However, if you have some cinamon or camomile tea, I would suggest using these methods in absense of a No Damp like product. YOu have nothing to loose and everything to gain. Just sprinkle some cinamon on the soil surface, or brew up some strong tea and water next time they look a little dry. (I would not add it to already wet soil).

RE: Is this a lighting problem?

I think we have cinnamon. Though it might be mixed with brown sugar.

So let them dry out, sprinkle some on, and then continue watering?

RE: Is this a lighting problem?

I think I found the problem. I read somewhere just now that the little flowers will wilt it they get water on them.

I had been lightly misting them so I didn't crush them with water droplets after they sprouted.

This time, whenever they sprout I will cease watering.

RE: Is this a lighting problem?

I would not add brown sugar to the soil... if it is mixed I would leave them alone.

However, I am a little confused, wilting flowers or the plant / seedling is prone to wilting? An easy and safe way to water is from the bottom up. Place the containers (or pellets if you are using them)in a tray of water and let the water soak up from the bottom.

This will disturb the seedling itself the least.

RE: Is this a lighting problem?

Oh maybe they said flowers wilting =/
Either way, after I saw these new sprouts I haven't touched them with water even though they're dry and they've stayed up for almost an entire day now.

For the containers, they're all little clay pots for now. 8" I think. Do I need to raise the pots a little from the water source? Seems like the water couldn't squeeze under the pot and into the little hole.

I remember someone giving me advice about using a wick.
But that was for draining. Could I use the same concept? With a shoestring maybe?

Also, how much water would I use to get the soil wet all the way up to the roots?

I remembered my other question!
I know using tap water is bad, and I read somewhere that some kind of distilled and spring water is good also. I was wondering if it was okay to water with Aquafina Purified water. We volunteered at a marathon not too long ago and they gave us some excess water bottles, like five cases tall of 1 liter bottles.

RE: Is this a lighting problem?

Aquafina is tap water. Personally, (I don't think unless there is something known about your water source)I don't think that it is a big deal to use tap water. I used tap water with all my plants and they seem fine.

What I would do, is fill a roasting pan, or even the kitchen sink with a few inches of water, put the plants in, and let the water do its job. it will get into the hole, or leech even through the clay and slowly water the soil. Check on it in an hour or two, and you should see that it eventually wicks all the way to the soil surface on its own.

RE: Is this a lighting problem?

And then how often should I do that? If the top of the soil is dry is the rest of it really? I wouldn't think.

I'll look for cinnamon and try that out too.

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