Whats your favourite plant ?

[West Ender]

I love gardening and I have loads of different flowers, shrubs, bulbs etc. in my garden. It's quite a small garden and I suppose it's a bit overcrowded really. My great passion, though, is growing plants from the seeds of fruit that we eat. I have a grape vine (from a pip) growing round a kitchen window, orange and grapefruit trees, 2 pomegranates, a passion flower, 2 lychees, 3 date palms and an avocado that is, as yet, just 1" above the compost. I also have a baby apple tree in a pot in the garden, grown from a braemar seed, but it's only 6" tall yet. I grew some acorns, 3 years ago, and I am growing little bonsai oak trees. Again, these are in the garden in a small tub.

Last year I grew cucumbers in my little mini greenhouse. I had 6 plants and got about 12 cukes from each one. I tried growing loofas from seed and they came up but didn't really thrive. I suppose England's too cold.

I also like cacti and in '03 I brought a couple of prickly pair fruits home with me from Malta (my spiritual home - I go twice a year). I planted the seeds (with advice from the internet) and got 6 babies growing. They are now about 2" tall but it's odd because they don't look like prickly pear cacti (opuntia). They look more like the ones you see in cartoons (with arms) but I know what their mum and dad looked like 'cause I picked them off the plant.

Anyway, after all that waffle, now for my question. I have a fair sized patio, part flags and part crazy-paved, and after all the weather it looks really dingey. It was covered in green film (algae) and I've got that off with a proprietory patio cleaner and a deck brush but I can't get it looking really clean. I've even scrubbed it with bleach but it's not a lot better. What can I scrub it with to get rid of all the black-ish colour, bearing in mind there are flower and shrub borders round it. Any ideas?