Easy to Grow UK Fruit and Veg

Hi,

I am thinking about starting a guerrilla growing campaign in my local city. I want to fill unused soil banks/ pots/ weed ravaged corners/ hedgerows etc. with fruit and veg for the community. I think that more people growing their own food is something that we need to do as a country, and we have the space! I am having some problems deciding on the type of plants to use though. 

I want to do long term grows in my local town, which is quite rural, and will be establishing gooseberry/ raspberry bushes in the hedgerows. I have no experience with planting either of these fruits, but I think that once established they do quite well in English countryside.

I'm also planning on doing shorter term grows in cities. I want to plant fruit/veg that can be picked, is easily identifiable and will fruit quickly once planted. I am prepared to incubate and grow the plants until they are at this stage at home before transplanting them. My problem is that I don't know which veg/ fruit to plant. I've only ever grown carrots, leeks, potatoes and beets. I was thinking maybe of tomatoes/ strawberries/ lentils/ quinoa since they can all be picked above ground and should be fairly apparent to most people what they are. Does anyone have any suggestions for better crops to grow?

Thanks,

Edd