You can often find spots where you can grow plants which normally are too tender for your locality. However, in a sheltered nook between the fence and the greenhouse, close to our cottage, petunias, Helichrysum petiolare and Argyranthemum frutescens all survived the winter, whilst those further down the garden perished. Similarly, the climber Solanum jasminoides 'Album' flourishes on a fence near the housewall, although it does lose its leaves during the coldest months. Sometimes you can't quite predict which are the most sheltered spots. Many gardens contain frost pockets, so it is wise to locate these areas and only use the most hardy plants there.
Frost tends to roll down hill, and if it is stopped by a barrier, then a frost pocket results.
An example would be if a garden sloped downhill to a brick wall - it is likely that the area in front of the wall would be a frost pocket, spelling death to tender plants. Growing in pots does give you the chance to move vulnerable pots into a greenhouse or under cover when severe weather strikes. Container growing is also useful for those plants that are susceptible to wet conditions, as drainage can be better in pots. On the other hand, the plant roots are more likely to be frozen solid in pots, than if planted in the ground. If you choose to grow your tender plants in the ground, then there are ways to protect them.