UPDATED: May 2020NEWS
How to Securely Fix a Garden Arch into the Ground
We are often asked what is the proper procedure to securely fix a garden arch into the ground, whether metal or timber, so here is a quick explainer for you.
If installing in soft ground, heavy wooden arches need to be secured with a quick-drying fence post concrete such as Metcrete or Postcrete (available from any DIY store).
You need to secure each arch leg in the ground to a depth of about 30cm (12"). Most garden arches are designed with this sort of depth in mind, so don't worry about losing too much height.
Blue Circle have produced a handy 2 minute video that runs through the process of using their concrete for fixing fence posts:
Ground Spikes for Arches
An easy fixing method, especially for lighter wooden or metal arches is to use ground spikes. You simply slot the arch leg into the spike (make sure you measure the width or diameter of the leg to get the right sized spike). The spike is then driven into the ground to about 20cm (8"), and provides a sturdy anchor for each leg.
On hard surfaces such as concrete or patios, you will need to get some metal fixing brackets to secure the arch in place.
Sometimes the retailer will have suitable fixing available as an option, otherwise a well-stocked DIY store should have what you need.
Metal arches are usually lightweight enough to be sunk into soft ground to a depth of about 40cm (14"). If the soil is a little firm then water it first or use a spike or pole to make a pilot hole first.
If you are worried about high winds buffeting the arch, then you can concrete the legs into the ground as per wooden arches above, or use suitable ground spikes if available.
An alternative method of securing an arch is to obtain two planter boxes (in a matching style to your arch) and fix them to the arch, one either side, fill them with soil and plant your favourite flowers.
As well as providing an attractive addition when the flowers are in bloom, the weight of the planters and soil will keep the arch rock steady.
Unlike arches which have longer legs, arbours are designed to be freestanding. You can secure them to hard surfaces with brackets as per wooden arches, or in soft ground you will need to screw a timber stake (about 30cm tall) to each leg, and then sink the whole stake into the ground. The arbour legs will rest on the surface.