Sweet pea tubes are a great way to grow sweet peas, or beans. Sow two seeds to a biodegradable tube & plant them out in pairs too, so they have no root disturbance. A strong paper-like organic material made from wood pulp, recycled paper & textile fibres 12.5cm deep, 5.5cm diam Root penetration of the sides & base will usually occur within five weeks. These also work well for beans, onions, leeks & tap-rooted plants.