How long does it take for red mangrove propagules to sprout roots?

[dochou]

I purchased some propagules from Ebay; they came from Florida.
I'm in the SF Bay Area and weather conditions are obviously much different.
I placed them in sand in a clear glass bowl with fresh water; no salt.
They've been sitting in the bowl with the bottom end in the water and sand for about 4 weeks. I leave them on a window sill that gets direct sunlight in my familyroom. I top off water periodically.
So far I've not seen any changes since day 1.
So my question is, how do I know anything is happening? Am I doing the right thing or is there something wrong?
Should I see some signs of life soon? Should I see the roots start forming?
Thank you.

 

[Timfish]

My experinece roots show in a few weeks. You might try using brackish water instead of fresh water. In an aquarium it's going to have a source of nitrogen and phosphorus but in a bowl of fresh water it might not be getting enough, you might try adding some drops of liquid plant fertilizer and search on line about growing them in brackish or fresh water. (Persoanlly I'd be using aquarium water to get it started and change it out frquently.)

 

[dochou]

I've read that they grow faster and larger when grown in fresh water.

 

[Timfish]

First I've heard that but I can't say I've spent a lot of time researching thier sprouting requirements. However, my first thought is if that's correct then I'd think mangrove forests should be along rivers and not along coasts. Can you post your refferences?

Just FYI, the mangrove in this tank showed new growth around week three and really took off about the third or fourth month.

 

[dochou]

Usually halophytes (plants that live in salty environments) will do better with little to no salt due to the fact that excreting salt requires energy. The only reason halophytes do not grow in fresh water areas is because there is more competition with other non-halophitic plants.

Julian Sprung says he hasn't seen much difference in salt vs fresh water growth. He also says fertilizer doesn't seem to make much of a difference. Watch this vid starting at 43:40


Julian Sprung's 1999 artical "Magnificent Mangroves" says,
"When I tell aquarists that mangroves grow perfectly well in freshwater they typically respond with amazement and disbelief, stating that they thought mangroves re q u i re d saltwater to gro w. It would seem that the Red Mangrove might re q u i re some salt as it is not found too far from salt water in its natural habitat. Nevertheless, I have found some Red Mangroves growing naturally in freshwater in canals and rivers that lead to saltwater bays. In the southern part of the Florida Everglades and along the gulf coast of Florida they grow in fre s h w a t e r, but there is a limit to how far they naturally occur f rom the sea, and I'm not really sure why. Perhaps it is intolerance to drying out, cooler winter temperature further inland, or simply the direction of water flow fro m land to sea. In aquariums the limiting factor doesn't exist; they can be grown perf e c t l y well in pure fre s h w a t e r, even soft water. They are quite hardy and adaptable! " https://www.twolittlefishies.com/images/mangrove_manual.pdf

This guy showed that fresh water had better growth.

 

[bnord]

I picked up a bunch on the beach 2.5 months back and tried 3 methods.
- floating in the refugium in holes in a styrofoam sheet under the AI fuge light
- in glass planters with brackish water buried in miracle mud under an old fuge light
- attached to the top of the tank they will go into , not anchored in substrate, and under T5/Radions

Firstly, all 3 did something, but there was tremendous inconsistency in the propagules. Some are still inert.

the Styrofoam propagules rooted the best by far, and those I put into glass containers and then under the T5s and they have taken off with leaf buds, but they are slow.

the placed in Miracle mud have done the worse by far, and I just cleaned up that experiment.

so not a completely controlled experiment, but it seems they can and do sprout in 35ppm.

 

[Karen00]

I agree with @Timfish, your water is probably too clean. Mangroves are the filtration systems of their environments. They like dirty water. I sprouted mine in a few weeks in my freshwater tank (roots first, then leaves). Now I have them growing in soil. They get what ever is leftover from my water changes. One week it's fresh, the next week is salt. I also periodically dose Seachem Flourish. I'm getting a bit concerned with how tall they're getting. Now I have to adjust my lights to point to their tops. I'm also in Canada so I'm not sure where they'll go if they outgrow my house.