mimosa hostilis woes ...

[jebus]

Hi guys,

I germinated 10 out of 15 mimosa hostilis seeds easily in 2-4 days under grow fluorescent lights and heat pad 18 hours light, one died and the rest all thrived. After about 10 days I pulled them out of the zip-lock bag and tried to acclimatize them to normal humidity under the same fluorescent lights and heat pad and 18 hour light cycle. This is what they look like now, I think they are dieng and I suspect its too hot and bright?, but any advice would be really appreciated.

Before I wrote this I did put then in a humidity dome and shaded the dome under the fluorescent lights with a piece of scrap fly screen.

Cheers guys

J.

[kadakuda]

probably too much light, looks like it. But they are fast adapting and are mostly lower leaves getting scorched. I would honestly play it out a little longer and if you notice new growth is fine, just leave as is. if new growth is having troubles maybe raise the lights a bit or cut down the hours a bit.

[Rabelais]

Under fluorescent lights I doubt it would be too bright and hot unless they are just a few cm away - what is the wattage and how far away is the light?

They do look a little crispy so I would guess it is the change in humidity...soil does look a little dry also.

But really, they don't look that bad! Probably just keep them in the higher humidity setup you have now and try not to love them to death.

Nice germination rate also.

[jebus]

probably too much light, looks like it. But they are fast adapting and are mostly lower leaves getting scorched. I would honestly play it out a little longer and if you notice new growth is fine, just leave as is. if new growth is having troubles maybe raise the lights a bit or cut down the hours a bit.

 

Thanks kadakuda for the advice, one of them has a leaf that stopped folding for the night so got me worried, I'd rather put the fly screen on to diffuse the light rather than raise it since I have some chilli's growing like crazy as well. And I thought that increasing the humidity a bit will allow them to recover.

cheers

J.

[Jonstn]

Hey mate I'd say just try and let em tough it out it'll weed out the weak for sure

They seem pretty tough so far, I had one snap when it was just sprouted but it kept going and it's one of the faster growing ones:

The one in front is suffering the same problem as yours, the only thing I did different was use a seedling mix instead of jiffy pellets.

Here's some of the others:

This one got knocked over in the wind recently, seems to be going alright still

And some others:

The seeds were just hot water treated for 30 mins then kept in a seedling box under fluro for about 2 weeks

[gerbil]

some very good points already posted.

I'm having a similar problem with the lower leaves browning off on some acacia and some general unhappiness, i had to bring some in due to cold wet weather for a few days, my situation i think is too heavy a soil that is holding too much moisture, Fluoros can be good, but if soil is too heavy and damp with seedlings, the lights can struggle to create adequate wet dry cycles, the top will dry but there is not enough root system to suck subsurface moisture out, which can lead to constantly wet almost anaerobic soil and therefore poor root development. So long intervals between watering is beneficial, but keep an eye out as you dont want it too dry.

Yellowing and browning off of the lower leaf tips can be a sign of overwatering / soggy soil / bad root condition, it's an odd browning and plant decay, kinda soft and pliable with sickness / lack of cell plumpness in the yellow bits that the brown continues into.

It's hard to tell, but your soil doesn't look overly appropriate for seedlings, quite large chunk pine bark which can almost compact and hold too much moisture, seedlings are best with a free draining small particle not too rich compost like mix. Not saying dig them up, but something to think about for next time. The soil can also cause nitrogen issues which is why they often pump it with fertiliser, i've ranted about the poor quality of bag mixes recently, producers should be disgusted in themselves imo.

I think a really detailed soil thread is in order one of these days, it's a really confusing topic that i'm still learning myself after a good decade plus of plant work, and can be really offputting for anyone new or old trying to get plants growing, might try get some notes together and put one up over the next few months...possibly

I reckon it could be potentially a combination of all three things of the posts here. Stress, light burn/intensity and bad root condtions.

just saw your JS, looking good, nice fresh healthy atmosphere, besides the seed mix and jiffy pellet, did you start any in that heavy pine bark or are they transplants?

Seed mix one looks a little hungry, are jiffy pellets nutritious?

Edited October 4, 2011 by gerbil

[Jonstn]

Nah buddy they all got transplanted to that barky soil after coming out the seedling box, now that I think back I did half the seeds in peat pellets and half seed raising mix, they germed faster in the seed mix (40 hours after putting them in they were popping up I was shocked)

Jiffy pellets have no nutrient at all, they didn't seem to mind to much though just gave them good ol water.

Cheers for the heads up about the hungry one I'll give it a little food

[kadakuda]

lets also keep in mind lower leaves (talking about your acacia, cause i dont know how large they are) always die back when low light is an issue. Think of the inside of a trees canopy, no leaves. they all died off and dropped cause there is no light. lower leaves dieing off once the plant grows i personally dont give any attention to. but the plants above are tiny and the upper leaves are too. lack of water makes wilt, not burn marks. that is surely too much light i think..just from the pattern of the burn marks.

MH are weeds though, tough as shit! but if you notice bad stuff spreading, especially if it goes to teh stem, its time for some change in plans.

[captaincactuscakes]

Mimosa is a very hardy species... I have a fan on mine and I intentionally stress them to toughen them up. The survivors are growing so fast and so thick they may need to be relocated soon. They love nutes too. Even if they get hurt they bounce back with a vengeance!

[gerbil]

re acacia, smaller than the MH pictured, def not a lack of light, definitely a good thing the lower leaves dieing off in your explanation kada, using up reserves and no use for em.

I tend to agree with the burn marks, esp with the evident yellow stress and crispy look.

cheers JS, keep seeing people using the jiffy, they are a neat idea, should trial some one day but too happy with seed mix and combos. Prob. don't have to feed em if they are just repotted, often it can cause more issues if it isn't actually the remedy needed, probably just taking a bit to get adjusted as the rest look quite healthy. I really like the environment posted, people can learn a lot from it, really communicates bright lit but not full sun, fresh and functional.

[OPP]

At least yours are still alive.

All mine died

[planthelper]

At least yours are still alive.

All mine died

 

than just try again, this time just, place the seeds outdoors, in a pot or direct seeding into the ground.

if you ran out of seeds, use the seed exchange forum to obtain some again,

no reason to be upset for too long!

[jebus]

Under fluorescent lights I doubt it would be too bright and hot unless they are just a few cm away - what is the wattage and how far away is the light?

They do look a little crispy so I would guess it is the change in humidity...soil does look a little dry also.

But really, they don't look that bad! Probably just keep them in the higher humidity setup you have now and try not to love them to death.

Nice germination rate also.

 

Dale Cooper mate thanks for the quick reply, I was secretly hoping someone would come to my aid .

The wattage is 110 (2x55)it was at about 30cm away.

thanks mate

[jebus]

Hey mate I'd say just try and let em tough it out it'll weed out the weak for sure

They seem pretty tough so far, I had one snap when it was just sprouted but it kept going and it's one of the faster growing ones:

The one in front is suffering the same problem as yours, the only thing I did different was use a seedling mix instead of jiffy pellets.

Here's some of the others:

This one got knocked over in the wind recently, seems to be going alright still

And some others:

The seeds were just hot water treated for 30 mins then kept in a seedling box under fluro for about 2 weeks

 

Jonstn mate thanks for the reply, yours seem pretty moist is that how you are keeping them all the time? and what's the weather like where you are?

cheers and thanks

J.

[Jonstn]

Nah I usually don't keep them as damp as it is there, been a few spouts of rain recently probably not going to water until it's dried up a bit, damn unpredictable spring!

But they don't seem to be too bothered by the moistness though

It's usually dry around here, but it's been wet as lately with a few really nice days here and there, and winter was pretty gloomy throughout. Started these about 3 weeks before the end of spring and kept them under a fluro until spring started then moved them into the sunroom, then eventually the shadehouse.

Bit worried about summer, it gets hot as hell around here (upwards of 40ish in the peak) and dry as a nun, the shadehouse has a busted irrigation system I'm gonna have to try and fix over the next few months, woop woop

[jebus]

some very good points already posted.

I'm having a similar problem with the lower leaves browning off on some acacia and some general unhappiness, i had to bring some in due to cold wet weather for a few days, my situation i think is too heavy a soil that is holding too much moisture, Fluoros can be good, but if soil is too heavy and damp with seedlings, the lights can struggle to create adequate wet dry cycles, the top will dry but there is not enough root system to suck subsurface moisture out, which can lead to constantly wet almost anaerobic soil and therefore poor root development. So long intervals between watering is beneficial, but keep an eye out as you dont want it too dry.

Yellowing and browning off of the lower leaf tips can be a sign of overwatering / soggy soil / bad root condition, it's an odd browning and plant decay, kinda soft and pliable with sickness / lack of cell plumpness in the yellow bits that the brown continues into.

It's hard to tell, but your soil doesn't look overly appropriate for seedlings, quite large chunk pine bark which can almost compact and hold too much moisture, seedlings are best with a free draining small particle not too rich compost like mix. Not saying dig them up, but something to think about for next time. The soil can also cause nitrogen issues which is why they often pump it with fertiliser, i've ranted about the poor quality of bag mixes recently, producers should be disgusted in themselves imo.

I think a really detailed soil thread is in order one of these days, it's a really confusing topic that i'm still learning myself after a good decade plus of plant work, and can be really offputting for anyone new or old trying to get plants growing, might try get some notes together and put one up over the next few months...possibly

I reckon it could be potentially a combination of all three things of the posts here. Stress, light burn/intensity and bad root condtions.

just saw your JS, looking good, nice fresh healthy atmosphere, besides the seed mix and jiffy pellet, did you start any in that heavy pine bark or are they transplants?

Seed mix one looks a little hungry, are jiffy pellets nutritious?

 

gerbil mate, oh damn so I did everything wrong huh hope they survive, but not looking good they have stopped opening up and dried up more I am confused the soil was dry so I wet (similar to Jonstn pics) maybe thinking they need soggy conditions, this did not help but I guess the damage could have already be done. So I am leaving them under extremely high co2 atmosphere and 1/3 the light and we will see what happens.

Thanks for the advice mate,

J.

[jebus]

Nah I usually don't keep them as damp as it is there, been a few spouts of rain recently probably not going to water until it's dried up a bit, damn unpredictable spring!

But they don't seem to be too bothered by the moistness though

It's usually dry around here, but it's been wet as lately with a few really nice days here and there, and winter was pretty gloomy throughout. Started these about 3 weeks before the end of spring and kept them under a fluro until spring started then moved them into the sunroom, then eventually the shadehouse.

Bit worried about summer, it gets hot as hell around here (upwards of 40ish in the peak) and dry as a nun, the shadehouse has a busted irrigation system I'm gonna have to try and fix over the next few months, woop woop

 

Thanks mate if any survive this (under my co2) I will just put them outside under shade cloth? any advice on where to get more seed, my last lot was from SAB and they were great and I will buy some more, I also bought some on ebay that I am waiting on but I am dubious as to the authenticity . I want some diversity and I want a good many to go to maturity... as many as possible.

Thnaks mate

J.

[apothecary]

Mimosa hostilis thread and everyone forgot the nitrogen fixing bacteria..

I found it didn't hurt to germinate my seedlings (admittedly a few years ago now, but the plants grew big and strong) in pots which had already been used to grow more prolific and hardier Fabaceae. My understanding is that there is generally a type of bacteria for each genus or even species but when I repotted the plants there was plenty of "nodules" of the bacteria on the root system.

If your soil doesn't have the bacteria present and conditions aren't correct for the small amount that may be assumed naturally present then you need to consider careful (foliar?) feeding to keep the plants happy.

Judging from your posted climate profile, I would also suggest simply putting the plants outside in a spot which gets sun in the morning and shade in the afternoon until it's time to pot them up or put them in the ground.

Nitrogen fixing bacteria on soybean roots (just provided from google images as an example) http://cache2.artprintimages.com/p/LRG/38/3817/ZBDYF00Z/art-print/wally-eberhart-nitrogen-fixing-bacteria-rhizobium-nodules-on-soybean-roots-glycine-max.jpg

[jebus]

Mimosa hostilis thread and everyone forgot the nitrogen fixing bacteria..

I found it didn't hurt to germinate my seedlings (admittedly a few years ago now, but the plants grew big and strong) in pots which had already been used to grow more prolific and hardier Fabaceae. My understanding is that there is generally a type of bacteria for each genus or even species but when I repotted the plants there was plenty of "nodules" of the bacteria on the root system.

If your soil doesn't have the bacteria present and conditions aren't correct for the small amount that may be assumed naturally present then you need to consider careful (foliar?) feeding to keep the plants happy.

Judging from your posted climate profile, I would also suggest simply putting the plants outside in a spot which gets sun in the morning and shade in the afternoon until it's time to pot them up or put them in the ground.

Nitrogen fixing bacteria on soybean roots (just provided from google images as an example) http://cache2.artprintimages.com/p/LRG/38/3817/ZBDYF00Z/art-print/wally-eberhart-nitrogen-fixing-bacteria-rhizobium-nodules-on-soybean-roots-glycine-max.jpg

 

apothecary thanks mate, great advice! Not sure how to fix it should I water with a bit of nitrogen fertiliser then? and maybe use some nodules form another nitrogen fixing species?

cheers mate.

J.

[jebus]

thank you kindly to all who cared to give advice and time to my problems this forum is a great community that shares advice and knowledge freely.

dont know how these seedlings will go but I have learned a lot for next time ...or as soon as I get some seeds again

anyone selling

Thanks and cheers

J.

[apothecary]

You can try an experiment, like moving half of your surviving seedlings outside and giving half of those fertiliser and the other half nodules, or some both fertiliser and nodules, same with the ones you keep inside.

Really it's a decision you should make as you know the nutrient content of the soil they are in, their conditions etc. Personally I would just move them all outside but I don't know precisely how cold it gets where you are.

IMHO once they get cranking you will be happy if even only a few survive because they are quite vigorous in the right conditions and as planthelper points out you can always go again with fresh seeds + the benefit of experience.

Edited October 6, 2011 by apothecary

[jebus]

apothecary mate I think I will try what you suggest, but not till tomorrow see how they hold up after tonight.

Thanks for advice,

J.

[Jonstn]

Keep a eye on the free ethno thread I've been seeing it pop up a bit there

I've heard they are quite easy to clone also ;)

Edited October 6, 2011 by Jonstn

[gerbil]

wooh apoth good to see ya round talkin all planty and stuff. Great point on the NFB.

So was in humidity and doing fine under 110w fluro at 30cm, then taken out of humidity at same wattage and distance and then the following is happening?

Maybe it is just humidity shock like dale mentioned and possibly a lack of N from them using up reserves?

Whatchya reckon kada? If light intensity hasn't changed, wouldn't it be leaning more toward a humidity shock issue, then possibly if not just humidity, yellowing and seedling leaf dieback from N deficiency? Though the lack of leaf opening possibly influenced from light intensity or humidity / both?

plant illness does my head in, one symptom could be caused by a range of possibilities, but it's really rewarding to figure out whats going on, but net diagnosis needs as much info as possible!

nah man not saying you did everything wrong jebus, people often have success with methods that i fail at and vice versa. Out of interest and for our info what soil mix did you actually use?

cmon plant docs chime in!!

[kadakuda]

i dont knwo a lot about plant disease/disorders either. but dropping humidity does tend to make leaves drop in a lot of species. When i grow M. hostilis (and any Acacia species that i have thus far sowed) i always do teh following with amazing results.

heat treat teh seeds (almost boiling water soaked for 12-36 hours).

when seeds swell i platn asap, leaving too long makes them seemingly explode.

i plant outdoors under my roof/deck thing. On the edge it receives almost no direct sun but is well lit all day. humidity here is generally never under 80% so it seems fine that way.

i try not to get too worried about low leaves/old growth as much as i worry about new growth in most plants. if i am burning the new growth i know its too extreme for the plant to cope with, or at least too extreme too fast, so i adjust the changes i made, whate ever they may be, in about half. i do notice once you see dehydration/wrinkles int eh stem in seedlings you are kinda fucked to be blunt. thats my experience anyway. But i never had any trouble with mimosa except for too strong light too early. after they reach a couple feet, especially in ground, its almost hard to kill them.

one last note, and keep in mind this was with about 100 seedlings in a 16"x12"x6" deep tray i had bad leaf drop after about 1 month. conditions were unchanged so it was obvious it was due to no available nutrients left in the dirt. this is why i like to mix in a weak amount of organic pellets for food, so there is some more margin for error if you rely on liquid ferts.