Can you share about the light exposure these planters receive? Doess the structure of the grotto shade the planters at all (and if so, what time of day)?

Secondly, does any water from the grotto/waterfall itself spray or drip around the planters? This will help determine what types of plants you can use too, since it will contribute to humidity and overall "coolness" in the groto.

The planters will receive full sun from about 11:00 - 3:00. However, there will a screen, so it will be more filtered sun, I guess. The grotto will not shade the planters at all, and neither will the water from the grotto spray the plants - although I'm sure it will add to the humidity. Thank you for your response.

Though I live in So. Cal (Z10-11), maybe this will give you an idea ...

http://www.imagestation.com/picture/sraid61/pa2ee4382adb7953978d203ed609cd521/fc3b883a.jpg

It's hard to see by the photo, however the pool platers are only 4 feet from front to rear.

Here is a link that might be useful: {{gwi:1302616}}

Hawaiian Ti plants would work well, mixed with ground hugging bromeliads like Neoregelias. I would look for more unusual varieties of Ti (other than the generic Red Sister of box store fame). Something like Wili's Gold, Peter Buck, or maybe the Black Magic Ti. An evergreen ginger like Costus "Green Mountain" or Costus varezareum (sp?) which has some maroon tones on the leaf undersides mixed with an evergreen like Zingiber Midnight and something like variegated Tiger Ferns and bromeliads would also look nice. Anthuriums (especially the Obake types) mixed with bromeliads, ferns and a dwarf aroid like Colocasia fallax or Colocasia Dwarf Jenningsii would look fine, maybe with some variegated purple oyster plants mixed in.

Bambusa tuldoides is medium sized bamboo, a clumper not a runner, that grows fast (I have 10 each 15 to 20 ft culms one year after planting a small division), with thick, wind-resistant culms, large dark green leaves. It wouldn't even occupy 1/2 of your planter after 3 years. Easy to push over sprouting culms or cut old culms you don't want, if you prefer a sparse, open clump mixed in with shorter foliage plants. You can also trim the branches on the lower nodes to expose the dark green culms and keep the leaves above head level. evergreen.

This seaon's naked culms have just stop growing in height, and haven't leaved out yet, but the 4 or 5 short culms I got between July and November last year have leaved up nicely, and sway beautifully in the breeze. here's a clump at 3 years old in Austin TX:

{{gwi:416469}}

Thanks for the ideas. We had some 'leaking' issues with the waterfall and grotto and had to hold off on the plantings while that was repaired. We are on a conservation with woods on two sides but a neighbors house close on the third. I had wanted to plant a bamboo hedge to screen our pool area from the neighbor's back yard, but my MIL told me it would get out of control and I would be sorry. Thanks for much for the tip about the clumping kind of bamboo.

Also I had planned on using the Hawaiian Ti and bromeliads, but I didn't know what else - thanks for the suggestions on the other plants. I'll definitely look for them.

"my MIL told me it would get out of control"

standard ignorance of the half-informed knee-jerkers.

use a clumping bamboo for hedge, no control required.