I've had a fantastic summer with a real complete break in France, and a week of trips out with my four year old son, but this last week i've been back in mine and other gardens. Although i've been on holiday, the bugs and beasties havn't, and every manner of Caterpillar, Slug, Vine weevil, Blight and Sawfly has congregated in my garden. I'll let you know about some of the others over the coming week, but the most important to find quickly in your garden is blight. This is what caused the Irish potato famine, and if you are growing potatoes or tomatoes outdoors, you need to spot it within a day of it starting. For it to develop you need a couple of days of warm wet conditions (oh yes like in an English summer!) and then the spores will work fast to turn the stems and leaves brown (this is called the Haulm on potatoes). The only prevention is to spray when conditions are likely to effect plants, but for those of us that garden organically, (or don't get round to spraying) the only cure is to remove effected plants the minute you see the problem. If Potatoes are earthed up deeply, then after removing the haulms, you have got a couple of days grace to remove the potatos before they turn to a mush. For tomatoes, all the plant must be removed and tomatoes can be left on a windowsill to ripen, but if they show any signs of going brown, throw them away.
I hope you escape blight this year, - i've learnt my lesson not to try greenhouse varieities outside, so let me know what types escaped and cropped well so that I can try them next year.