What exactly do you think these were used for?

For tomatoes growing in grow bags? To stop slugs and snails maybe?? Um....

For very fat leeks? Or Rhubarb? Definitely 'Um'.... as Hazel says. Haven't a clue - interesting to guess, though. If you don't mind a bit of fun, let's have a guessing game until someone who REALLY knows tells us! Gold star for the best suggestion...

I agree with Hazel...my first thought was slug traps..my guess is that they just drown in the moat, so-to-speak...lol. If slugs are a problem...they don't like to cross copper...these items are made of plastic...but similar of copper would be quite effective agains slugs. Put a little tipple (beer is attractive, If you can spare it.)into the reservoir and it's au revior...! did you mean that putting warm water around the plant roots would force them into bloom? to increase humidity? maybe. very interesting...I will follow this..

Definately looks like something you'd use in a grow bag, but I'd be inclined to fill the edges with slug pellets and have slug free hostas. They love to munch the fresh growth so the hole in the middle would be small enough to pop over a young plant....it would probably have to stay in situ otherwise the plant would grow too big to pull it over without damaging leaves.

hi i have seen these advertised recently in a gardening catologe - and yes they are defo for tomatoe plants in grow bags, but alass i no longer have the catologue to look it up for to see what the reason for them is - but if i remeber rightly it is something to do with retaining mosture and raising the level of the soil (grow bags are quite flat and tomatoe plants very tall????) just guessing the last bit! lol but they are for tomato plants in grow bags i can tell ya that much for sure ............ heres a thought - are tomatoes like Clematis - in the respect of liking there roots and base of the plant cool? that could be it? to be honest i don't think they would prevent any slugs in my garden! lol they are olympic gold medalists when it comes to these sort of devices!

Ive found them! On a garden equipment website. Yes, you were right Majeekahead, they are for tomatoes.
The advert also says: "For years I’ve been trying to convince my Dad that using Grow Pots makes growing tomatoes so much easier ... they not only let you provide your tomato plants with more water (they are notoriously greedy ... just like me!) they also mean it’s quicker to give them water in the first place – as we all know watering into a grow bag often means watering the surface below!

Not only do they help with the watering, but because grow pots have an inner and outer ring, you can plant your tomatoes in more compost than just that in the grow bag (not a bad thing) whilst you can also use this inner pot to give your plants some much needed food as they start to produce their fruit."

yes, thought so! Which makes me wonder - why grow in grow bags at all? What an ultimate waste of space and cash. I've always used tall pots with funnels or cut plastic bottles inserted, to ensure water and feed reaches the roots. I have yet to see a deep enough, visually-pleasing growbag! And - you have to dispose of the plastic bag at the end of the season. How environmentally-friendly is that?

seen something similar in a recent gardening catologue. it was a device to water tomato plants in a grow bag, hope this helps.

Thank you all for your ideas. The consensus is then that they are for use with growing tomatoes in grow bags. (Which unfortunately I do not use) It makes sense - the resovoir does have little holes in it.

We use them in the tunnel where the tomatoes are grown in the soil. You fill the 'gadget' with compost and plant the tomato in it. then you feed into it and water the soil outside of it, stops the food from being wasted.
We use growing bags (bark based, not peat) in the greenhouse with a concrete floor, easier than filling pots.
We also make our own of these gadgets by cutting the bottom off a larg plantpot and putting that on the gorw bag/soil.