Soon in the spring time, you will need to start planting your plug plants into baskets, protecting them from the spring frost, and eventually planting them outside in May time. As far as purchasing them, the best plug plants in the UK I have found are at Babyplants (http://babyplants.co.uk), where their packaging was much more robust, and protected the little plugs a lot better than some others we have tried. The geraniums even had some beautiful flowers on the top, an added bonus, as these are supposed to be very small starter plants. You can buy their plug plants online here delivered to the UK mainland.
Geranium Plants and Plugs for Hanging Baskets
Really the two go hand in hand, geraniums plug plants are perfect for hanging baskets, as well as tubs, and garden borders, with their beautiful broad leaf flowers, taking the time to bloom in the bright sunshine. When thinking about planting out your Geraniums, you want to make sure that the Geranium plants have a solid root ball, with plenty of outbound roots to make sure they pot on and grow fully when out in your garden.