A circular vegetable garden ?… well there are a few good reasons :-
1. The maximum enclosed growing area for the minimum boundary fence line is a circle.
2. No corners, means no high stress corner posts and no unstressed middle posts. ie. fence tension is divided evenly round all the posts
3. A tractor powered rotovator may be simply driven round & round (no headlands required for turning)
4. Central island is ideal for perennials eg, Asparagus, Herbs etc or even perhaps a geodesic greenhouse/fruit cage/shed.
5. A central vertical pole with an rotatable overhead ‘radius’ arm with a hose pipe attached makes watering easy
6. Straight lines and corners are simply not natural. Everything moves in cycles and circles, follow the flow ……
The outer wall is made from a double layer of old railway sleepers, laid in overlapping fashion (as bricks are) and drilled vertically through to accept two 25mm diameter steel posts per sleeper. The posts lock the whole ring together and support the fence. A personal gate and a tractor gate allow access. The outer ring is 20 metres diameter, the inner is 8.
The use of a tractor rotovator will over time displace soil outwards towards the periphery of the circle and create a shallow drainage ditch just outside the inner circle. A soil pipe buried below implement depth carries away excess water. The soil near the outer fence is deep and well drained – ideal for root veg like carrot, parsnip and potato. Closer to the inner circle the soil is shallower and wetter, butternut squash, courgette and pumpkin do well here grown on mounds of compost.
The inner circle is enclosed by a circle of half sleepers banded by tensioned fence wire to hold them in place. The surrounding ditch ensures good drainage. I grow perennials such as – asparagus, rhubarb, herbs and strawberries here.
A water pipe feeds a central tap for the overhead watering arm. (Windmill see in the above photo is now redundant).