what are the best plants for a rock garden
Most things described as 'alpine' should be suitable but check that anything you fancy isn't described as 'invasive' as if they are you will have an awful time trying to remove anything which takes over. There are lots of knowledgeable folk here so you could post a list after browsing around a few supplier sites and I'm sure someone will warn you against any to avoid.
It's going to depend on what you want them to do and what size you're thinking about?
Do they need them to be beneficial to wildlife?
Is it a sunny site or in a shady corner?
Do you need ground cover?
Personally my plants need to be attractive to pollinators so I plant perennial ground covering plants like Campanula, Arabis and Aubritia. These love a sunny spot where I also sow seeds for summer flowering wildflowers such as California Poppies and Corn Marigold. This makes a lovely vibrant and low maintenance display for summer that will be covered in bees and pollinators.
I also like some of the low growing Sedums for adding something a bit different and again they like a sunny spot. I have one which is lovely and I think it is Sedum 'Lime Zinger' from memory....
Another interesting plant that I like in among the rocks is Persicaria affinis and I think the one in the picture below is 'Superba' It is evergreen and I grow it alongside Bugle Ajuga Reptans that has bright Purple/Blue flowers and burgundy foliage which looks good with the Persicaria. I will warn you that this combination can be quite 'vigorous' and will require a bit of space as they spread.
Persicaria affinis 'superba' (I think!)
Most of my suggestions are on a large rockery and aimed at pollinators so if you have a small rockery or want more 'traditional' type plants then these may not be for you but I though worth a mention for something completely different from the norm..
Most people mean a small raised alpine bed or small rock garden, which needs plants that don't grow wider than (say) 20cm.
It's different if you have got a massive area, then you can choose the alpines that are bigger than that.
Don't choose any rockery plants that require protection from the winter wet - meaning that they will almost certainly die over the winter.
For a list of suitable alpines with a width of 5cm to 20cm see http://boundarynursery.co.uk/product-tag/rockery-plants-5-to-20cm/
Peter, it's great to have someone with your knowledge and experience on the forum, but Gardener's World who provide this facility free, are a business dependant for their income on advertising. Don't think it's really on to plug your own business for free while other advertisers pay - don't want to be all schoolmarmy about it but thought I'd point it out.
When's it best to start sorting a small rock garden say in a stone trough
Thanks Dovefromabove I missed "are a business dependant for their income on advertising" from the small print.
'Have a go Nick': You can start doing a stone trough at anytime - provided you use hardy plants, but it obviously won't start growing until it warms up slightly.
Additional thoughts (my brief comment was too brief!)....
If you plant up the trough and leave it outside and if the compost is not bone dry, then let the rain water them in (but obviously it will need watering in the hotter months).
There are one or two plants, like Sempervivum, that won't like being put into a lot of compost at this time of year, but most will be okay.
I would not recommend planting the trough and keeping it in a glasshouse until it is warmer, because it will start to grow a little and the shoot tips become susceptible to Grey Mould (Botrytis).
My OH is developing an enthusiasm for alpines - I started him off by planting sempervivums where he could see them from his studio - bit by bit the interest is increasing - now he's talking about getting a trough - a Modernist trough with sleek lines, but a trough for alpines nevertheless - I'll turn him into a gardener yet
would a big wooden bottom half a barrel be any good
Yes, but drill plenty of biggish holes in the bottom for drainage and you can put in some old broken clay pots above the holes to prevent them getting blocked up.
This is my rock garden,I also have two real rock gardens.
I like that Bill
Having read all your comments about rock gardens and seeing the GR programme, I've decided to resurrect my 2 'butler' sinks and plant alpine plants.I'm going to rest the smaller sink into the bigger one. Possibily raise the smaller sink, sitting it on a brick. Now I'll need compost and plants...my spring project.
That's what you call a rock garden, Bill! Very nice.