The slow-growing dragon plant (Dracaena marginata) can measure up to 1.8 m (6 feet) tall when grown indoors. Its spear-shaped leaves, tinged with red or yellow on the edges, grow between 30 and 40 cm (12 and 16 inches) long on a woody stem, according to Guide to Houseplants.
You can use any general potting soil mix, as long as it drains well. For tightly packed soil, aerate it by adding peat moss, perlite or sand.
Light and temperature
Although the dragon plant shrub can tolerate low light, it grows best in bright, indirect light. Normal room temperatures -- between 15.6 and 23.9 degrees Celsius (60 and 75 degrees Fahrenheit) -- or greenhouse temperatures up to 29.4 degrees Celsius (85 degrees Fahrenheit) will suffice.
Use warm, non-acidic water to keep the soil lightly moist from spring to autumn. Allow slightly drier soil in the winter, but never let it get too soggy or the root may start to rot.
Use a liquid fertiliser every two weeks during the spring and summer months. Older plants may need weekly fertilisation during the warmer seasons.
The plant tolerates dry air in the winter, but this could attract spider mites, thrips, scales and mealybugs. To deter these pests, regularly mist the plant with water.