I just have a small water garden...Actually put it in a half barel with fish and plants...Did this last year....I put the plants at the level of water they were to be at and they all eventually died.....Have no idea why....Can you help???
Plants dying
Could something be leaching out of the 1/2 barrel? What's it made of? Did the plants get the right amount of sun? What potting medium did you use? WM generic clay kittly litter (the kind with no additives of any kind) seems to be the best ( and cheapest ) potting material. How did the fish do? If they stayed healthy that means your water was OK. Other than those issues I can't think of anything else.
Sometimes stuff just croaks too. Last week I got a mail order "Bog Bean" marginal water plant which arrived healthy. I planted it within 1/2 hr of its arrival and I believed I planted correctly. Today it looks pretty much dead to me! I'm stumped.
I have a plastic liner in the tub and it was basically in full sun....Th water grew algae to start with and the fish person gave me something to put in the water for that....Half the fish survived...and the plants I left in the soil I got the plants in...so I have not a clue what was wrong.......
Some things like pond block you can not use if the ponmd has plants.
Read the label and see it it is ok for fish and plants.
Check the PH. Koi can take a high PH but plants cannot.
I'm assuming that since this is a tub garden the fish were goldfish, not koi? If some fish survived the pH was probably ok. Some algae killers are not plant safe. If you still have it can you check the label?