Plant out the garden-flowering varieties this month. Weather permitting, the first week is the ideal time in the south, but wait a little longer in the midlands and north.
  After raking the bed prepared in March and April, set the plants in the same depth as they are in the pots. Planting too deep checks subsequent growth. As each plant is removed from its pot, turn it upside down and dip the entire plant in a weak solution of insecticide. Firm the plants just enough to keep them upright, but not so hard as to damage the tender young roots.
Support chrysanthemums
The most convenient way to grow flowers for cutting is to use welded wire mesh with 8 in. squares. Lay this flat on the ground and attach it to stout posts at the corners. Plant in the centre of each square or each alternate square, and raise the mesh to support the plants as they grow.
  Set plants for garden decoration, including pompoms and Koreans, 12-18 in. apart in any direction. Insert stout canes or stakes close to the plants and tie the plants loosely to them. Pass the raffia or twine gently around the plant, them around the cane, and tie there. Leave plenty of the material so that it can be loosened as the plant grows more bushy. Water each plant thoroughly. Give no further water for several days, but spray lightly to counteract the effects of sun or drying winds.
  Scatter slug pellets among the plants, renewing it as necessary until the plants are well established and the stems have become hard. In the north, plants grown for decorative purposes can be stopped from the middle of the month onwards.
Under glass
Except in the north pot on late-flowering varieties into their final 8 in. or 9 in. pots. To ensure free drainage, place a layer 10 mm. stones in the base of the pot.
Final potting
For this final potting use John Innes No 3 potting compost or a proprietary soil-less compost.
  One-third fill the pots with compost, firming it down. Knock a plant out of its pot, complete with the ball of soil, by inverting it over one hand, with the stem between two fingers. Stand it upright in the centre of the part-filled larger pot so that the top of the soil ball is 1 in. below the rim. Fill in around the plant with new compost, firming it as you go, until it is level with the top of the soil ball. Fill the pot to the top with water and allow it to drain through. Do not water again for seven to ten days, but spray with clean water at mid-day during warm weather.
  Insert three 5 ft. canes, equally spaced , into each pot as soon as potting is complete, and tie the main stem of the plant loosely to one cane.