I grew okra for the first time last year, so I'm no expert. But FWIW, I grew three emerald okra in a 15 gallon container in the 5-1-1 mix discussed in the container forum (5 parts pine bark fines, 1 part peat and 1 part perlite). They grew seven feet tall and the pot was filled with roots by the end of the season. So my guess is you would need a pot that holds at least 5 gallons for each plant. You also will probably need to stake them (I did) and find a way to keep the pot from being blown over in the wind. I grew them about the same way I grow peppers, with regular fertilizer and allowing them to dry out between waterings. They turned out pretty well and had few pest problems. Plus, the flowers are very pretty. You just have to remember to harvest each okra as soon as it gets 3-4 inches, or the plant will stop producing.

Agree you'll need as big a container as possible - like a half whiskey barrel or bigger - and stake or tie it somehow as okra will get very very tall.

As to what 'soil' to use? No soil. Soil-less mix only as with all containers.

Dave

I grew my clemson spineless in 5gal buckets sunk 1/3 into the ground. I used regular potting soil with some compost mixed in. I harvested quite a bit of okra with absolutely no problems what so ever. The plants got to be 4-5 feet tall. I wouldnt go less then 5gal, and you can get thebuckest pretty cheaply.

If you're not in a hot summer zone, use dark coloured containers. Okra likes warm soil.

Grew Clemson Spineless in 5 gallon bucket with home made mix (1/3 ProMix BX, 1/3 coir and 1/3 Perlite with Tablespoon of Osmocote). Fertilized with MaxiBloom 5-15-14 weekly. Clipped each leaf when I harvested the 3" pods. NO branching at all. They have been very productive. Will plant 4 per 5 gallon bucket next year. They only get about 4-5 hours of afternoon sun on the deck. Over 5' tall now and beginning to show signs of stopping production (9-1-2015).