Hi I looked at the link, just as a point I thought I would mention that the Lois Hole book that is offered on the link in not one I would recommend anyone to buy.
It does have some useful information in it and I found it useful in Canada for such things as planting zones, last frost dates etc but beyond that it is out dated. The information is of little value to someone in the UK.Further if you remove the chat type writing, which is interesting for a first time read, and get down to the actual part of rearing your tomatoes it is very sparse, Lois uses fertilisers etc that many of us don't use, and the varieties she suggests are few and not very inspiring compared to today.
Just thought I would mention that.
XX Jeannine
