Definetely a cylinder (to match the watertank??? or am I confused)
No it doesnt come pre curved. But it is quite flexible. You could even use the reinforcing netting (they make a 90cm wide one) and wrap that around the outside, wired to the top and bottom circle.
How big are your raised beds? Are they even circles?
You will rotate them depending on the season more than any arbitrary time limit. During spring and summer you are throwing so much garden waste in they dont need to move at all plenty to eat and scratch up. Which is good cause all your beds will be producing veggies then and you dont want to have to move it in the middle of the tomatoes cropping...
During winter you might move it around a couple of times, but then you are only growing cabbage, beans and leeks in winter, and you can only eat so much of those....so you will have free beds.
If you have 3 raised beds thats enough. You would leave them on one (1) for the whole growing season. Then move them to the tomato bed (2) once it is finished cropping and throw on all the garden waste you have in for them in there.
In the one they were on in summer (1), you can plant your Cabbages and brocolli etc which will love the nitrogen. The third one (3) you can do anything with (generally you autum planting, but you will move the coop onto it (3) at the end of winter. You cannot move it to the one still growing your winter cabbages (1), but it only just had the coop this summer so doesnt need it.
Does that make sense. 1 for spring and summer, 2 in late Autumn and winter, 3 in spring summer, 1 next winter 2 next summer etc....
The time on each bed is more about your ability to feed the system with waste than the size.
Gotta try and do some work before 5pm....
I love this stuff.
Breeder of Blue Laced Red Wyandottes.