They will adapt to new surroundings much faster than older plants. Plant much closer in a box or basket than you would in a flowerbed. Include plants with a variety of colors, shapes and textures. Trailing plants should be planted at the edges and bushy or upright plants will go at the center or back. Be sure that the taller plants will not block your windows or interfere with hanging the basket.
Site selection is as important for baskets and boxes as it is for any other plant.
Remember that most of the time the hanging basket will be viewed from below. Hang the basket so that it will be close to eye level so that it can be admired and watered easily. Window boxes should extend the entire width of the window for best appearance. Soak the sphagnum moss overnight in very warm water. Squeeze as much water out of the moss as you can.