Jim is in among a crowded Beechgrove border. These acid loving lovelies are enjoying the conditions so much that they are taking over and need a bit of taming. One of them is a huge juniper that is now straddling and obscuring the path, and Jim tries his hand at a little topiary that may turn into some drastic pruning.Lesley is in the potager garden, a mini garden that aims to be both pretty and productive in a very tiny space. She is starting off edible flowers and salads, both in the potager borders and in the bite-sized barrel greenhouse.Carolyn visits Lorna Sinclair in Edinburgh. Lorna has a tricky problem with Japanese knotweed, which is starting to invade her garden. Carolyn talks to plantlife expert Deborah Long to find out why it is such a problem and what can be done to eradicate it.Japanese knotweed is a hugely invasive plant that was brought into Britain from Japan in the mid-19th century as it is very pretty, but has since spread all across the UK through water courses and railway lines. It is estimated that it has cost the Olympic site £70M to eradicate it. It's a headache for developers, landowners and house owners, and DEFRA has estimated that the cost of a national eradication programme could cost £1.56b. In the light of that, what can Carolyn do with Lorna's problem?Carolyn also visits Angela Davey in Wormit in Fife. This is a one-acre Edwardian landscaped garden with panoramic views over the Tay. Special features include rhododendron walk, rockeries, informal woodland planting schemes using native and exotic plants, providing year-round interest. Original raised paths lead to a granite grotto with a waterfall pool, and the granite features again in the shape of raised vegetable beds made out of granite sets. A real gem of a garden.