Koubach iPlant Sensor 2 Pro

1 We know it sounds a bit mad to have an expensive Wi-Ficonnected sensor jammed into the soil of your plants, but it’s worth it. Pick the variety from an extensive catalogue and it will tell you on your iPhone when to water and fertilise it, and if it’s getting enough light. And if that’s all you need, you’d be as well to get Parrot’s Bluetooth Flower Power (£47). This Pro version of the Koubachi Plant Sensor 2, though, has a powerful web portal for professional growers, letting you export raw data for further analysis, and set up custom alerts. Christopher Phin

Overkill for all but the most passionate home gardener, but potentially huge for professionals and researchers.