My plants do seem to be later this year, and I don't really know why. When I compare my notes from previous years, things are about 3 weeks later in general. I did reduce the temperature in the greenhouse for the winter to a minimum of 5C rather the 7C of previous years, to try to keep the costs down - and be "Green" as well. But also I have some overhanging tall Scots Pine trees, and it may be that the shade on my greenhouse is getting too much, and keeping light levels down. I know I have to get the tree cutters in to remove a couple of very big leylandii, and they can do some climbing as well and sort the pine trees out. It will keep the greenhouse roof cleaner as well, as the grey squirrels sit up there and gorge themselves on the pine cones, and do what is natural after eating.