Plants in Foam?

[Ghost in Souls]

One thing that always bothered me when making a vivarium, how could the plants survive being rooted into the expanding foam? Or in other words, can they?

 

[pannaking22]

I think people tend to use air plants or plants with a minimal root system when placing them in foam. That or they manage to put a tiny pot or chunk of soil in with the roots to make adding fertilizers possible. Though I admit I haven't made a viv before so I'm not completely sure.

 

[The Snark]

how could the plants survive being rooted into the expanding foam? Or in other words, can they?

Interesting question. Expanding foam, polyurethane diisocyanate, is closed cell, the reason why it is commonly used as an insulator in refrigeration applications; air cannot pass through the cellular structure. However, the foam is slightly osmotic and moisture can slowly permeate the cells. Sounds like experiment time.
A word of caution: the foam can harbor molds. Once mold establishes itself in the foam it's impossible to get rid of. The foam must be replaced.

When I was working in a refrigeration plant we had a 19 cu ft fridge returned to us. It was oddly shaped, bulging a little at the bottom, it had become energy inefficient and it had a nasty odor. We weighed the unit. It weighed 48 pounds more than it was supposed to. The inner liner had a leak and allowed moisture to condense in the foam. It had almost 7 gallons of water in the foam. When we cut it open GAHH! Ultra foul smelling black moldy goo instead of foam.

 

[schmiggle]

A word of caution: the foam can harbor molds. Once mold establishes itself in the foam it's impossible to get rid of. The foam must be replaced.

What's the mold eating? The plastic itself or something else?

 

[l4nsky]

Usually, the plants aren't placed into the foam per say, but into small pots that are incorporated into the foam during construction. It's a good idea to stuff the pots with paper towel when constructing the background so the expanding foam doesnt invade the pot and to drill holes through the foam and pot after its cured for drainage.

Thanks,
--Matt

 

[The Snark]

What's the mold eating? The plastic itself or something else?

We need a microbio specialist person to answer that. But as I understand it, there isn't much molds don't eat and the colonies don't require much sources of nutrients. The particulate matter in water and air is sufficient, and some colonies will parasitize their neighbors. I'm not reading anything that would rule out isocyanates, which are organic compounds, as a food source.
I wondered about this when we have checks of the HVAC ventilation systems in hospitals which commonly harbors molds. 99.6% particulate filters and only the ambient humidity for moisture but the colonies were able to thrive.
I also recently learned molds are musclebutts. They can power their way through FRPs like what most bath tubs are made of, actually establishing colonies within the plastic then the rhizoids expanding create pockets that cause the slick inner surface of the tub to bulge and allow the stolon and sporangiospores to penetrate the otherwise waterproof inner surfaces.

 

[l4nsky]

We need a microbio specialist person to answer that. But as I understand it, there isn't much molds don't eat and the colonies don't require much sources of nutrients. The particulate matter in water and air is sufficient, and some colonies will parasitize their neighbors. I'm not reading anything that would rule out isocyanates, which are organic compounds, as a food source.
I wondered about this when we have checks of the HVAC ventilation systems in hospitals which commonly harbors molds. 99.6% particulate filters and only the ambient humidity for moisture but the colonies were able to thrive.
I also recently learned molds are musclebutts. They can power their way through FRPs like what most bath tubs are made of, actually establishing colonies within the plastic then the rhizoids expanding create pockets that cause the slick inner surface of the tub to bulge and allow the stolon and sporangiospores to penetrate the otherwise waterproof inner surfaces.

I wont claim to be a mold expert, but when doing some research into Aspergillus niger (black mold) as a possible source of mycosis in centipedes, I discovered they are oligotrophs, or organisms that can survive or thrive in environments with almost zero nutrition. All they need is a little moisture. Some molds have even been shown to use radiation as a fuel for growth in places such as Chernobyl. They are surprisingly adaptable.

Thanks,
--Matt

 

[The Snark]

I wont claim to be a mold expert, but when doing some research into Aspergillus niger

The bad news heavyweight is Stachybotrys chartarum. As bad or worse than Niger. At a clinic here we were able to isolate and culture Stachy from spores floating on 50% hydrogen peroxide!
But which is which is academic, these horror story organisms are survivalist extreme and are basically the second rung of the ladder; a sine quo non of all life on the planet. A lovely little ironic paradox.

 

[Ghost in Souls]

I also see a lot of people planting moss in their vivariums, on the coco fiber coated foam, or driftwoods, etc. How do they do that?

 

[Ghost in Souls]

Usually, the plants aren't placed into the foam per say, but into small pots that are incorporated into the foam during construction. It's a good idea to stuff the pots with paper towel when constructing the background so the expanding foam doesnt invade the pot and to drill holes through the foam and pot after its cured for drainage.

Thanks,
--Matt

Do I need a pot, or can I curve a pot-shaped sinkhole

 

[l4nsky]

Do I need a pot, or can I curve a pot-shaped sinkhole

I wouldn't recommend it. If you put plants in there with vigorous root systems, there is a chance that they'll grow in and through the foam. The plastic pots I use are cheap as dirt (like 40-50 cents) and just make things easier.

Thanks,
--Matt