Nymphaea tetragona

water lily (syn. N. pygmaea 'Alba')

• Position: full sun
• Depth of water: 15-30cm (6-12in)
• Rate of growth: average
• Ultimate spread: 40cm (16in)
• Height above surface: 0-10cm (0-4in)
• Flowering period: June to September
• Hardiness: fully hardy
  
  Small, slightly fragrant, cup-shaped white flowers up to 5cm (2in) across with slightly scalloped petals float atop round, mid green leaves from June to September. These award-winning pygmy water lilies will happily grow in as little as 15cm (6in) of water, and they are perfect candidates for a small pond or tub in a sheltered, sunny site. The shade cast by the leaves also helps to check the spread of the algae.
  
  
• Garden care: Plant firmly in a hessian-lined aquatic planting basket filled with aquatic compost. Apply a 2.5cm (1in) top-dressing of pea shingle or gravel to prevent the top layer of the planting medium from clouding the water. The crown of the plant should protrude slightly above the surface of the planting basket.