I use fabric root pouches like these.
https://www.amazon.com/dp/B09X3VQR1...&colid=RATU5HRCLXAV&ref_=lv_ov_lig_dp_it&th=1 They come in various sizes and can easily be gathered and tucked if needing to get one too large. I do have substrate trays beneath them and waterproof barrier (tarp) just in case, but so far I don’t believe it’s been an issue. Many keepers also use pond liner to contain drainage, but then you’ll need to set up a way to remove excess water.
Thanks yeah it's not water containment I'm worried about ,just excess water, was thinking two drainage pipes up the back ,as I would like to get as large an enclosure as I can going to be for a male panther, but don't want a swamp , a member of another group said once their bio was established their plant roots lapped it up and have no issues, just want to be sure . Thank you