Water.

[Heather]

I just need to be clear on this please. When potting a cutting, rooted or un-rooted do I water or not? Should I wait a couple of weeks before watering?
Sorry, this may seem like a really stupid question but I am a complete newbie to this.

[CactusFanDan]

Rooted or unrooted, for any cactus, I'd leave them a week or two after repotting before resuming watering. This gives the roots enough time to heal over any damage caused to them when transplanting. If you water them too soon, fungi and bacteria can get into the wound and cause an infection (rot).

I think people are divided about watering unrooted cuttings or not. Some say a little water in the soil mix when they're resting on the soil can help to encourage rooting, while others prefer to wait it out using dry soil mix. I add a splash of water to the soil mix of the plant I'm trying to root. It seems to encourage rooting, but it's important not to moisten the soil too much and to use a very well draining soil mix. As you're in the UK, you may or may not have heard of the best (or one of the best) medium for growing cacti in. A lot of growers like to use Tesco cat litter in their soil mix, or some use it completely neat from the bag. The kind you want comes as small pink/orange pellets that can't be crushed between your fingers. It comes in a pink bag and it's called 'Tesco dust-free, lightweight cat litter'. I believe it's also sold at the Co-op. It's cheap and makes excellent cactus compost.

[Heather]

Many thanks Dan!

[Peterthecactusguy]

I live in the dry desert of Central AZ, and I almost never water cuttings with no roots. In fact I often don't even have them in soil. Cuttings many times can survive for a long time without water. They will put out roots as they dehydrate. Once they have roots then I can put them in the ground, or in a pot. I will of course water them. I do have some cuttings in soil, with no roots, but I do this rarely. Most of the time I let them sit in a box out of the sun. The humidity is very low here anyways, so watering the soil lightly does nothing, really. It would dry out anyways. Just my .02 cents on the subject. What works for me however may not work for others.

[Heather]

I am a great believer in doing as nature would do in my garden so I am more than happy to do the same with my Cacti. The difference is, though, that they just don't have the same conditions here in England.
I do have an Opuntia bud/pup ( still learning the terminology) that I may try just leaving to root somewhere as you do Peter.
Thank you for your reply.

[Peterthecactusguy]

well when I do the rooting usually I follow what works in nature. Here in Arizona when a pad gets knocked off a cactus for whatever reason, it can happen in the middle of monsoon season and it will likely start to root and then die, or it can happen in winter and freeze or something, or it could happen in fall or spring before it rains too much and it will slowly root. Once it's rooted then it can handle the rains, cold/heat, etc. One thing I have noticed tho is that the pads will not survive if they are in full sun. So I mimic this as best I can.