What to pay?

I think £20 sounds about right - a bit more if you value your plants!! Might be an idea to let him know that he'll be rewarded, just to make sure that he keeps up the good work and does the job properly and you don't come home to a garden full of 'cornflakes'

The minimum wage is £7.50 an hour. If you think he's going to do 4 hours then it's £30. If you don't want to just give him cash to blow then give him half in cash and half in a suitable gift card like ITunes (ask his parents which is best because it depends on the phone he has).

I'd go with £30 ,he might be able to buy a second hand game for his consul for that or a ticket to see a band .Everything is so expensive now and we always make sure the young kids who deliver our milk and newspapers are well tipped.Its good to see them trying to earn some cash so we like to reward their efforts

After being mugged in a similar situation I would wait to see what you come back to . A neighbours adult son said he would look after our garden and put bins out for us one year . We came back to a garden full of brown wrinkly plants and hanging baskets and a bin full of maggots. Never asked him again .

The minimum wage for his age is £4.05. £20 seems fine for me for 3 to 4 hours work.

Perhaps £25 , half way between. If he does a good job you may want to ask him again

My 17 year old dgs earns £5 ph as a pot wash in a pub if that helps.id pay him generously so he won't mind doing it again.

Thanks all, looks as if I'm on the right track.
I do take the point about 'waiting', however, I think his parents will make sure it gets done!
I would normally in fact, not pay until return, but the family are actually leaving for their holiday the day before we return, so it would be nice to give him some holiday spends.

I don't think it's fair that he gets paid less that an adult would for the same work hence £7.50. It's not as if he's training or learning a skill. If young people do the same work in the same way as someone over 25 then they should earn the same money. If they're in training and benefitting in some other way from work then fair enough but if it's like for like there should be no differentiation.

Sorry bit of a hijack but wanted to explain why I felt he should get £7.50 an hour.

You won't be paying him until you get back so you can change the amount if he hasn't kept to his part of the deal. I take it you're not going to tell him how much you're planning to pay him.

Thanks vampirequeen, I had realised that was why you calculated at £7.50, and I think you have a good point.
However, I will be working to a lower amount for the following reasons:

I don't want to step too far out of line from others locally - this will only be the second 'job' he has picked up, and I don't want to raise expectations too high! I wouldn't take that too far, but it is a consideration.

His next job step will almost certainly be glass collecting / pot washing at the pub, and will be £5 an hour.

Actually I think he is learning the skill of doing a job to expectations (and I take the point about not paying him until he gets back, and may re-think that)

My own sense is to keep it a bit lower this time, and see how it goes, but I thank you, in the spirit of this forum for making the point.

I agree with the suggested amounts. I would probably also get him to do half hour or so before I left so I could instruct him on what's expected.

I had a young guy helping out on Saturday mornings when I ran a livery yard. I started paying £8 an hour and went up to £10. I think £30 would be fair for the work you have in mind.

I know a 20 year old who's on £3.50 an hour on an apprenticeship. and 17 year olds on £4.05 - £5 for pot washing. I personally would think twice before giving their 14 year old brother £10 an hour for watering a few plants. Of course you can pay what you want, but I think you have a valid point, Nannarose, about expectations and stepping out of line with others. £20 might well equate to nearly £7 an hour anyway.

I like the idea of getting him round to show him how to do it. The real question though is what is it worth to you? Have you got a queue wanting to do it? Would your garden be OK if left? If the answer to both is no, then be generous - horrible idea about ' stepping out of line'. Have a word with his mum in private, tell her you'd like to give him some money for his hols but get back after they've gone so will she take it and give it to him at the starl of the hols. Tell him what you've done and say you're sure he'll do a good job - be generous with your words and cash.

thank you, yes,I will be showing him what to do, and as I know mum quite well (she's a smashing neighbour) I may take up Rigby's suggestion.

My granddaughter and boyfriend, both 21 year old students, will be working long hours on their feet for the summer at £7.50 per hour. This is usual among their friends.
I think a few hours watering next door is a minimal job and he would be very pleased with £20.