black tips on sunflower seedlings - help!

Schenectady, NY

checked my newly transplanted sunflower seedlings today, and there were black tips on the emerging true leaves!

what is it? what can i do about it? is it a fungus? can i still save them? please, please, please help!

Thumbnail by pokokpenyu
Dublin, CA(Zone 9a)

I can't really see the black tips well enough to tell anything for sure, but fungus is probably a good bet. Next time you water you could try putting a bit of peroxide in the water, and I've also sprayed seedlings with neem oil and haven't noticed any bad effects.

However, it also looks like the base of the seedling's stem is skinnier than the top, which is generally a symptom of damping off and that's not reversible. It could be that the picture just makes it look that way--when you look at the actual seedling would you agree that the base looks skinnier?

All these potential fungal problems suggest that there's a bit too much moisture around--you might want to cut back a bit on the watering.

Silsbee, TX(Zone 9a)

Here's a site I'm sure you'll find very interesting. http://tomclothier.hort.net/
There's an entire section about seed germination, the part about damping off should answer a lot of questions for you right now.

I agree w/ what ecrane had to say, but would like to add that I've often used chamomile tea and/or ground cinnamon with great success. Both are natural anti-fungals, cheap and easily found.

Is there any way to water your pots from the bottom? Seedlings like to be watered from the bottom best.

Schenectady, NY

thanks so much for responding.

i checked out the article on damping off, and it's really good. lots of handy suggestions. i'm not sure it's damping off though, as the base of the plant seem to look okay. it doesn't have any of the mentioned symptoms - bulged/waterlogged/lesions/discolouration. am i missing something?

i'm attaching a photo here, so hopefully it's a little clearer whether the base of the stem is thinner than the top. it seems the same to me, but maybe i am just being willfully blind.

the black parts have grown a little larger than this morning, and i've tried looking everywhere to see what it could be a symptom of. do you think it might be altenaria blight (http://www.ikisan.com/links/ap_sunflowerDisease%20Management.shtml)? or pottassium deficiency (http://highplainsipm.org/HpIPMSearch/Docs/FieldKey-Sunflower.htm)? or am i even crazy to be searching on information like this?

my friend thinks it might also be because the leaves got wet from yesterday's heavy rain. what do you reckon? i'll try the chamomile tea tomorrow. is it just standard one tea bag to a mug thing? sorry for being such an amateur.. and thank you!


Thumbnail by pokokpenyu
Silsbee, TX(Zone 9a)

The altenaria blight or potassium deficiency I would have to research, I really don't know about those things off hand. However, that stem pic looks good to me. Maybe ecrane or someone else will pop in and know more about those other things.

For now I'd stick with the chamomile tea. There is such a thing as doing too much and trying too hard...at least in my opinion. Less is more when dealing with plants most times.

When I make my tea I usually make a lot and use it on all of my seedlings. I'll fill a stock pot w/ water and bring it to a boil then throw in a bunch of tea bags. I don't really measure anything, but it's good to have the tea on the weak side rather than too strong. I allow the tea bags to sit in the water until it's somewhat cool. Let the tea cool completely before using it on any plants/seedlings...it can be warm, but not HOT.

And, hey, don't ever apologize for learning! We've all been there. =^)

Dublin, CA(Zone 9a)

Your stem looks normal in this pic so I don't think it's damping off, must have been the angle or the way the lighting was in the first pic that made it look that way. Chamomile tea is a good idea, it does pretty much the same thing as the hydrogen peroxide that I suggested, some people use one and some use the other but I think they'll both work. I also agree about watering from the bottom--a lot of times there'll be a little bit of fungus in the soil, and if you water from the top, then that fungus gets splashed up onto the leaves and then you get fungus spots, watering from the bottom can prevent that. Since you mentioned a heavy rain yesterday, I suspect this is a possibility.

So here are the things I would do if I were you 1) next time you water use either a bit of peroxide or the chamomile tea, 2) don't water from the top (bottom watering and protect from rain splashing until the seedlings are bigger), and 3) be careful in general about the amt of water they get, the more moisture is around the more likely you are to continue to have fungus problems.

Schenectady, NY

heya,

thanks so much for the advice again. i tried the chamomile tea because the idea of peroxide is a little scary for me -- wouldn't want to mess up and ending up killing them!

put them under florescent light and away from the balcony last night, and since it was super sunny, put them out today. i'm not sure if they look any better or worse. one of the seedlings is pretty much chomped up :( but the others look like they are hanging on. hopefully it'll work, and it wont get any more damage.

i'll post back once i have good news (being hopeful). thanks again!

some photos here: http://pokok.gejala.org

Dublin, CA(Zone 9a)

Be careful on sun exposure if they aren't used to being outside--even bright light indoors doesn't compare at all to the intensity of real sunlight so you need to work the plants up to it gradually or else they'll end up dying of sunburn.

Hopefully the chamomile tea will work for you, but peroxide's not scary as long as you start with the stuff you buy at the drugstore which is 3% active. I've heard of people pouring that straight on their plants and not having any bad effects. Personally I dilute it but I'm not super careful about the measurements (I use a couple capfuls in a small watering can full of water) and I've never had any problems.

Schenectady, NY

update about sunflowers -- they have all died except for two that's kinda still hanging on. not sure what the problem is. tried the chamomile, but it didn't work. put under sun, didn't work. tried putting transplant starter on one of the pots -- accelerated the dying process! hopefully the two will somehow manage to pull through. if not, i guess i'll have to start another batch.

:(

thanks for advice though. wouldn't have known about the fungicides otherwise!

Dublin, CA(Zone 9a)

Sorry to hear they didn't make it! With seedlings since they're so small they will often have a harder time recovering from fungus than a full grown plant would, but if you keep some of those tips in mind for next time hopefully you can catch the problem earlier next time (or prevent it from starting in the first place)

Silsbee, TX(Zone 9a)

If you don't mind I'd like to suggest something for your next batch of sunflowers....

Because sunflowers grow into such huge plants and because they grow so fast they are usually started in situ which means in the place they are going to grow. If you're going to grow them in a pot, start the seed in the pot you're going to grow it in and don't worry about transplanting. If you're going to grow them in a flower bed, start the seeds there. Don't start more than one seed per pot, don't use seed starting or soilless mix, just use the potting soil or whatever you plan on growing the sunflower in. Also, if growing in a pot then put the pot where it's going to grow and leave it there. Don't move it indoors and back out again. If frost threatens then cover it with an old blanket or sheet, cardboard or a bucket...be sure to remove the covering before the sun is high in the sky or it will wilt your plant. I doubt that at this point you'll be getting freezing temps, but if you do just bring the pot in overnight and take back out asap in the AM.

When planting your sunflower seed water from the top (this is a good time to use your chamomile tea), then water from the bottom if possible. If that's not possible then you want to do everything you can to keep the water off of the seedling. Once your seedling develops real, true leaves you can begin to fertilize with something like Miracle Gro, but only at 1/2 or 1/4 strength...look up fertilizing seedlings for more info. Too much fert can be bad.

That's my $0.02 and exactly what I would do. If you're planning on having these on your deck how big of pots are you planning on keeping them in? You're going to need some big pots. Think plastic, they don't heat up and they hold water better, plus they are lighter. They aren't all plastic looking or as ugly as they sound. They are also cheaper...go look at your dollar store. You can also paint them w/ spray paint if you can find the color you want. There are also ways to make them look more like aged terra cotta.

Good luck!

Post a Reply to this Thread

Please or sign up to post.
BACK TO TOP