Plant success over seasons and recommendations

[Sgooosh]

Hi! after growing a few species of plants for a while now, I've noticed some things: (mostly Val gigantea and Rotala rotundiflora, also water lettuce)
During summer in my fish tank, these do very poorly, and just sit there and melt most of the time
during winter in my fish tank, they grow very fast and lush.
Outdoors, they do well almost all year round, growth is especially fast during spring.

My tank goes up to the 90s f in temperature during the summer, and the outdoors is almost constantly higher than that during the day.
The tank is 79 degrees in winter, outdoors is much colder, down to like 30.

Do you know if this plant growth difference is caused by temperature?
if so, what stem, or tall growing plants can tolerate these high temperatures?

 

[Colin_T]

Giant/ jungle Vallis and some species of Rotala, as well as Bacopa are cool water plants.

Water Lettuce is tropical but doesn't like high humidity caused by coverglass or enclosed hoods above the tank. It needs lots of air flow above it and good light.

Ambulia, Hygrophila polysperma, narrow and twisted Vallis do well in warm water and get to a reasonable height (twisted Vallis being the shortest out of them and reaches 12-18 inches high. The others can get to 3 or more feet long.

Amazon sword plants and Cryptocorynes like warm water. Some species of sword plant can get huge while the Crypts tend to remain small.

 

[Sgooosh]

Giant/ jungle Vallis and some species of Rotala, as well as Bacopa are cool water plants.

Water Lettuce is tropical but doesn't like high humidity caused by coverglass or enclosed hoods above the tank. It needs lots of air flow above it and good light.

Ambulia, Hygrophila polysperma, narrow and twisted Vallis do well in warm water and get to a reasonable height (twisted Vallis being the shortest out of them and reaches 12-18 inches high. The others can get to 3 or more feet long.

Amazon sword plants and Cryptocorynes like warm water. Some species of sword plant can get huge while the Crypts tend to remain small.

Do you know if there's a way to stop the val melt in summer? The photo taken in my pfp is my giant vals at it's prime, which takes the whole winter to grow, to just melt instantly in summer.

 

[Colin_T]

The only way to keep giant Vallis in warm water is to have a massive pond that is more than 6 feet deep and grow the plant in that. You could use an air-conditioner in a room to keep the tank cooler but it's not really suited to aquariums due to its size.

 

[GaryE]

A thought - in summer, I take my kayak out on eastern Canadian rivers. I'm out there weeks after the ice has broken up, and what do I find? Elodea canadensis. Vallisneria americana. Ludwigia repens (I think) and hornwort. Tropical plants? Nope.

A friend found an aquatic moss, like a java moss. He won't say where, but it was local. He grows and sells it year round, hence the secrecy. Not all the plants the stores sell as tropical are tropical.

If I collect before mid July, they overwinter and acclimate. Beyond that, they die off when the days shorten in autumn, even away from a window under artificial light. They get water of up to 25c in summer, but most of the winter are at 22-23, going down to 19-20 sometimes.

Photoperiod seems very hardwired in them. Temperature-wise - many Crypts love it here. Amazon swords, Valls, giant valls, a number of stem plants, Anubias, Bolbitis and java ferns. But plants from temperate climates like it cooler, and seem to have rigid internal clocks, once they start up. I can stop the trigger by early harvests and trick them into a life of endless summer. But once the timing mechanism is rolling, it's rolling.

Could you be seeing the effects of a climate you may have never been in, but that your plants evolved in?

 

[Sgooosh]

A thought - in summer, I take my kayak out on eastern Canadian rivers. I'm out there weeks after the ice has broken up, and what do I find? Elodea canadensis. Vallisneria americana. Ludwigia repens (I think) and hornwort. Tropical plants? Nope.

A friend found an aquatic moss, like a java moss. He won't say where, but it was local. He grows and sells it year round, hence the secrecy. Not all the plants the stores sell as tropical are tropical.

If I collect before mid July, they overwinter and acclimate. Beyond that, they die off when the days shorten in autumn, even away from a window under artificial light. They get water of up to 25c in summer, but most of the winter are at 22-23, going down to 19-20 sometimes.

Photoperiod seems very hardwired in them. Temperature-wise - many Crypts love it here. Amazon swords, Valls, giant valls, a number of stem plants, Anubias, Bolbitis and java ferns. But plants from temperate climates like it cooler, and seem to have rigid internal clocks, once they start up. I can stop the trigger by early harvests and trick them into a life of endless summer. But once the timing mechanism is rolling, it's rolling.

Could you be seeing the effects of a climate you may have never been in, but that your plants evolved in?

that may be the case! But it's somehow reversed, as the dieback happens in summer, when days start to get longer, and it doesn't happen outdoors even in a very small 20g pond that gets kind of cold

The only way to keep giant Vallis in warm water is to have a massive pond that is more than 6 feet deep and grow the plant in that. You could use an air-conditioner in a room to keep the tank cooler but it's not really suited to aquariums due to its size.

okay, is it because mine are just getting too long in my tank? Will frequent trimming help keep them in shape?

 

[Colin_T]

Length has nothing to do with the plant dying unless the plant gets so long it covers the surface and stops light getting down to the bottom. Even then I would think there should be enough light hitting the plant on the surface to keep it alive.

It's most likely the constant warm water. Low light levels might contribute too but I don't think it would be that much of an issue if the plant grows well the rest of the year. It probably just gets too warm in your house for the plant. I can't grow it here either. As soon as summer hits it just melts.

 

[Sgooosh]

Length has nothing to do with the plant dying unless the plant gets so long it covers the surface and stops light getting down to the bottom. Even then I would think there should be enough light hitting the plant on the surface to keep it alive.

It's most likely the constant warm water. Low light levels might contribute too but I don't think it would be that much of an issue if the plant grows well the rest of the year. It probably just gets too warm in your house for the plant. I can't grow it here either. As soon as summer hits it just melts.

alright, that makes sense I'll just try to grow more ferns and stuff and hope that it provides enough coverage! i also move some fish outside temporarily so there's less intermingling (sometimes leading to fighting)