Experience In Growing Mangroves?

[maurizio]

Hello all,
I posted this in the brackish section, but no answers...

Anybody with experience in growing mangroves? I know some of you has it...

Please look at my latest post, and see if there's something I can do to help, at least the one with nice leaves: some of them are developing black spots.

I add about every week 10 shots of Colombo liquid fertilizer, and that's pretty much it.

SG 1.002 @ 25 C. I do spray the leaves about one a week with demineralized water, although I believe it's not striclty necessary, given the very low salinity.

Cheers!

 

[gregswimm]

It could be from a rapid change in salinity. The key is to find the salinity they were originally kept at, match it and bring it to your level over a months time. What is your C, Mg, and Fe at, I know these are heavily used by mangroves (especially the Mg and Fe). They need very rich soil dense soild, 'miracle mud' is perfect, it is high in iron and it goes anaerobic rather fast. Excess oxygen in the substrate can lead to root rot, but I'm not convinced this is what you are experiencing.

Most people keep the roots only a few centimeters under the surface and force the roots to grow a very long way. This leads to a 'root tangle' look. Some even go so far as to continue to raise the plant as the roots grow this further exacerbates the root tangle look. The theory here is that the plant will put all it's effort into growing a root system. Growing no more than 2 leafs while setting up the basics for an expansive root system. Once the roots hit the soil, root growth slows in favor of leaf growth.

Here is a good article: http/www.wetwebmedia.com/mangrovetrees.htm

Just a reminder, it is not unheard of for a mature mangrove to burst a tank.

 

[maurizio]

Thanks Gregg,
I actually took one of the seedlings straight from the tree, and I always take care that no sign of germination is visible if I take them from the ground. I'd rather opt for the lack of nutrients option, I just have sand, no substrate. I tried to measure Fe, but the test keeps giving me 0 mg/l, no matter the weekly dosis of liquid fertilizer. I'm wondering if fertilizing with tablets would help?

Most people keep the roots only a few centimeters under the surface and force the roots to grow a very long way. This leads to a 'root tangle' look. Some even go so far as to continue to raise the plant as the roots grow this further exacerbates the root tangle look. The theory here is that the plant will put all it's effort into growing a root system. Growing no more than 2 leafs while setting up the basics for an expansive root system. Once the roots hit the soil, root growth slows in favor of leaf growth.

I'm indeed one of them, but I have no vertical room enough to move the roots out of water, so they stay in. The idea of the effort concentrated in one task only would explain why bir roots apparently correspond to poor foliage.

I'm aware of Calfo's article, and would also recommend this, which I believe is more recent: http/reefkeeping.com/issues/2004-12/ac/feature/index.php.

Leaves growing vertically very close to each other, and black spots on the leaves, would you say it's too much light?

Any further help is greatly appreciated!

 

[gregswimm]

Thanks Gregg,
I actually took one of the seedlings straight from the tree, and I always take care that no sign of germination is visible if I take them from the ground. I'd rather opt for the lack of nutrients option, I just have sand, no substrate. I tried to measure Fe, but the test keeps giving me 0 mg/l, no matter the weekly dosis of liquid fertilizer. I'm wondering if fertilizing with tablets would help?


I'm indeed one of them, but I have no vertical room enough to move the roots out of water, so they stay in. The idea of the effort concentrated in one task only would explain why bir roots apparently correspond to poor foliage.

I'm aware of Calfo's article, and would also recommend this, which I believe is more recent: http/reefkeeping.com/issues/2004-12/ac/feature/index.php.

Leaves growing vertically very close to each other, and black spots on the leaves, would you say it's too much light?

Any further help is greatly appreciated!

That's good you took it right from a tree. It is always better to acquire a seedling that has yet to sprout/make contact with water. What species is it? I think iron rich root tabs would help more than dosing into the water column.

The dark spots could be several things. What lights are you using? How far away is the plant from the source?
If you mist the leafs when the lights are on the water droplets tend to have a magnifying effect (much like a magnifying glass on an ant hill) causing areas to burn. A phosphate deficiency can cause black spots on the leaf.
It could be heat stress, you will almost always get heat stress before light stress, especially with MH and flourescent. With heat stress the leafs curl (like a taco) and/or tips burn. Symptoms show themselves slightly differently on every plant but this would be my best guess.

Stick your hand under the light (palm down) at the same distance the plant is. You should be able to keep it there for a min without it getting uncomfortably warm.

Check the marijuana growing forums. Some of those guys have a sixth sense for growing terrestrial plants. I know grass city has a non-cannabis section.

I see no reason why this chart shouldn't be applicable to you, assuming you are running MH and your bulb has active air flow past it (also important to T5s).

 

[maurizio]

The dark spots could be several things. What lights are you using? How far away is the plant from the source?
If you mist the leafs when the lights are on the water droplets tend to have a magnifying effect (much like a magnifying glass on an ant hill) causing areas to burn. A phosphate deficiency can cause black spots on the leaf.
It could be heat stress, you will almost always get heat stress before light stress, especially with MH and flourescent. With heat stress the leafs curl (like a taco) and/or tips burn. Symptoms show themselves slightly differently on every plant but this would be my best guess.

Hi again,
it's red mangrove, and I must say, apart from being a beginner, I have a very-low tech: standard 2x38W 6500 K tubes, T5. They are about 10 cm above the leaves, but there's also a 2-3 mm plexiglas sheet in between, which lost some transparency, due to salt/limestone incrustations from the water. I wonder if these tubes could possibly heat-stress the plants in any way...

Thanks!

 

[gregswimm]

I would suggest moving the light to 20cm, remove the plexi(if you can) and add fan to move air past the mangrove (oscillating is best but anything is better than nothing). Air movement is one of the best thing for heat stress (it also forces the plant to grow stonger leafs and stems).

After a week if it shows improvement go ahead and move it a few cm closer and wait another week before moving any closer. Continue doing this until you find a 'sweet spot'.

 

[maurizio]

Cheers Gregg,
I moved the plant in a more shadowed area, and also finally settled its very long single root into the sand. After about 10 days, the root has clearly increased in diameter, a very good sign; and two more leafs are coming soon. A little fragment of fertilizer tablet was added today in the vicinity. I still have much the same 10 cm of distance leaves-lights, unfortunately, since the propagula is very tall, and that long root easily hits the bottom of the tank! I know, it's a TREE, and I do have to accept this. I do need the plexiglas on, unfortunately, I have archers. The plan is indeed to keep some of these plants as long as they can reasonably stay, and then have some new more take place.

Checked the heat, as I expected I almost need to touch the tube to feel any heat: that's at least on my skin!

 

[gregswimm]

I know I lost all of my mangroves when I transplanted them. If you still have seeds that have yet to germinate, I would keep them dry until you figure out if you need to remove a plant or not. They will last for a year or two if kept cool and dry.

Here is one of my new ones. If your leafs look like that its normal.