Ants milking aphids on my climbing rose

I took this photograph way back in July.  The rose is a climbing rose called Compassion.  It has big fragrant pink flowers.  Just as it was coming into bud I noticed it was covered with aphids guarded by ants.  I didn't want to spray it with anything as I like ants - I didn't have anything to spray it with anyway -  but I love the rose.  Anyway I waited to see what would happen.  And all was well.  The ants fed, the aphids thrived, and the rose bloomed, and is still blooming today, though no aphids or ants to be seen.  The aphids will probably all have died now and will overwinter as eggs, and the ants will be underground; just emerging when the sun hits the wall.

Aphids are bad news indoors, in the greenhouse and on seedling and small plants, but bigger plants outside just seem to take these things in their stride.  Also to thrive in my cold, wind blown garden plants have to be tough anyway. I feed and water them for a year, but after that they are on their own apart from a bit of pruning and mulching when I have the time.