I have had several friends ask me about this and i thought it was a pretty well known trick but i did a search and nothing jumped out at me so here it is.
I like to use hydroton ( LECA) as a mediaum in my mix and it is small and round and likes to escape from any container especially a wide slat basket soooooooo...what to do?
Shade cloth!
Lath house by
J Solo, on Flickr
start with a square about twice the size of your basket (okay it is really 4x the size because that's how squares work) and then cut away the corners to make a big +
Lath house by
J Solo, on Flickr
orient the shade cloth so it lines up with the basket and push it down into the basket
Lath house by
J Solo, on Flickr
use a scissor, screwdriver, spike stake, or any other long thin thing and push the top of the cloth through the highest basket slat
Lath house by
J Solo, on Flickr
add some leca, then the plant, then fill around with media of choice
Lath house by
J Solo, on Flickr