Posted: 20/05/2016 at 13:15
I will make a start then......phormiums, although not tropical, look tropical and grow well in pots. Red, green and yellow varieties.
cannas...superb from mid summer onwards. Again check out foliage colours in Tropicanna Black, Pretoria, Durban etc. Flowers 7' or more. Aeoniums, agaves, echeverrias, diosmas all thrive in dry conditions.
colocasia black coral......as black as a plant can be. Needs a deep saucer under your pot. Check out a classy grass, hackonechloa. In a pot it is superb. Forms a mound that then cascades making a shimmering, moving in the slightest breeze, effect. Yellow leaves suffused with orange and red tints but again place a saucer under the pot. Many grasses will grow well in pots...miscamthus, deschampsias, festucas, and stipas all add movement and class. houttynia chameleon....NEVER PUT THIS IN THE GROUND....looks psychadelic in a pot. Red, pink,,yellow, orange and green leaves topped with orange scented flowers in summer. Another for a saucer.
tree ferns, if you can locate a reasonably sheltered spot there. Hedychiums...gingers....will grow in large pots and look very tropical.
can I offer a word of caution re membrane? It is difficult to move plants later and there are other problems with using it. If you forget the membrane and mulch thickly your plants will thrive. They will still, eventually, spread beyond their area under membrane. I have a phlox planted in an area of my garden that I "membraned" a few years ago. It has now grown a metre or so away from initial plant...the membrane does break up eventually. My view is membrane looks ugly, is ugly and restrictive.
Weeds will still grow over membrane. Roots will spread under and over it and with great vigour to get to the light.
Hostas and ferns will grow well in the ground as well as in pots. Foliage colour from acteas if in the ground or convolvulous cneorum in pots (silver velvety foliage with pure white glistening flowers and need very little attention) sedums like Posties Pride or Purple Emporor will give you almost evergreen purple succulent looking foliage
burying pots in the ground doesn't kill the plants. They just don't grow as well and need more maintenance, watering and care.
Choose your plants with care....research which of them will be invasive if planting in the ground.
A thick mulch creates a healthy soil too and looks so good
anyway hope some of this helps