Smallest planting hole?

Astraeus

Hey folks,

We are about to lay our new patio. It will be edged with cobbles and then there will be a narrow bed between the cobbles and a fence.

I would like to plant a climber (possibly hop) up the fence so need to factor in a planting hole between the cobbles and the fence. I have read variously that it should be no less than 15cm, no less than 45cm or no less than twice the size of the rootball. I am keen to keep it as small as possible. What width would people recommend?

The reason to keep it as narrow as possible is because the line of the cobbles will run along the 10m length of the patio but the planting section will only be along this 2m length. I don't want to have a 45cm strip which, for 8m, is unplanted.

Lizzie27

If I understand you correctly, you only want to plant this one plant? If so, there is no need to to have a long bed of soil between the cobbles and the fence, just dig a hole a little bigger than the pot the plant comes in.  What do you intend to do about the rest of the strip though, grass it or put gravel down?

pansyface

Lots to consider. Rain shadow being one of them. The water retention capability of your soil being another. Lie of the land? Would rainwater run away or towards the bed? Aspect? Is it in full sun all day? 

Your plant(s) will need adequate water and the space you have left for rain to achieve this is very limited.

robairdmacraignil

The usual recommendation for paving in a garden is for it to be slightly sloped away from the house so water is not left sitting on the patio and does not flow into the house at times of heavy rain. This water may be channeled towards the planting hole if you lay the patio to suit this. Not sure if you are only planting the one climber why you want the non paved area to stretch for the 10metre length of the patio. The hole twice the size of the root ball sounds just like the standard directions given for planting any garden plant and does not take into account the full grown size of what you are growing or the nature of the soil. Some paving is laid in a way that allows water flow through it into the soil under it when the paving is placed on top of gravel while in other situations the water can not get through the paving like if it is set on a solid concrete base so this is also a factor in deciding how much of an opening is required for the plant to have access to sufficient water.