What's the difference between a balcony garden and a garden garden? The number of pests and diseases you notice. They're probably all there in the garden, but with such a large number of plants, the majority are liable to survive. In the London garden this year I only really had three problems.
The first was predictable - blackspot on the roses. I spray every time I'm there, but it's never enough. The second was a surprise - one of the cotoneasters half dead from red spider mite or something. But it was a big plant and after I'd cut back the three quarters that was badly affected, hosed it down and then sprayed, it bounced back with no problems.
The third was something you don't get on a balcony - slugs and snails. I've always liked snails and when I was a small child, used to keep them as pets in a cage. (I was horrified one day to find them all joined together in pairs. Having failed to pull them apart, I rushed screaming into the house to tell my mother, who reassured me that they were "just playing". And lo and behold, the next day they were all back to normal). I can often find two or three hundred or more in the garden over a two or three week period. Most of the time they're welcome, as they do the work of keeping down the weeds that the tenants usually don't, but once I've finished clearing the garden, and start to plant out seedlings, they become a nuisance. So I do a snail hunt, stick them all in a bucket and transfer them to the wildest part of the park behind the house - which is also the most remote from any other gardens.
Slugs though have always been a different matter. There was something about them that turned my stomach and I could hardly bear to pick them up, even with gardening gloves, to put them in the bucket. Imagine then the horror when I didn't realise that one had fallen into one of my gloves - until I started poking around in the fingers to find out what the squishy thing was.
This year though, there were so many in the garden - a lot more than usual and much bigger than usual, that I started to get interested. And by the end of the holiday was a convert. I'd not realised before how beautiful they can be.
So when I got home to my books and the internet, I started to do some research. It's difficult to be sure at a distance and I wish I'd taken more photos, but I think most of the ones in my garden were, like the one in the photo, the orange variety of the large black slug.
I also saw some Leopard slugs though - and if you really need convincing that slugs can be beautiful, have a look at this video of leopard slugs mating from the BBC. The Karma Sutra pales by comparison.