It’s useful to have some idea how damp the soil is in a polytunnel. Soil sensors can help with this as an alternative to sticking a finger the ground.

But you can only site them within a metre or two of the control box and you only get two.
The problem is that in a longish poly tunnel, moisture levels and readings vary a lot.

This means that using the sensors to trigger watering can be a bad idea. Either you get no watering at all, if the sensor is sited in a wetter bit, or ( as in my case ) they can go off every half an hour if they are in a dryer bit – drowning the poly tunnel and draining the battery.

It looks like the only solution to this problem is just use the sensors as rough guide and not to trigger watering events. Maybe this function could work if you were cultivating a tiny area and just using drippers but I’m not sure. Anyone had a positive experience of using them?

One problem I'm having with the wired sensors is their unreliability. Sometimes they work sometimes not but mostly not. All the connections are tight. Maybe not enough power during the winter from the panel? As both sensors fail at the same time, it seems like a problem with the control box or maybe the y connector? Any ideas?

Hi Bill - we are getting reports of unreliable wired sensors with some versions of the control box/sensor pairing, but we've not yet ascertained the exact combination which causes trouble. I'd like to offer you a wireless soil sensor to try when they are available ( which are more reliable than the wired ones, as well as being more flexible in that you can put them anywhere ). Would you like to trial one? We expect pre-production versions in the next couple of months.

That would be great - thanks. Please let me know when the wireless version is available.