General

Lilies can be grown year round as a greenhouse crop and outside in periods of no frost. Bulb sizes for commercial production range from 12/14 cm in circumference to 16/18 cm in circumference. For commercial production of Asiatics, the size 12/14 is generally used, for Orientals the sizes 14/16 and 16/18, and for L.A. Hybrids the sizes 12/14 and 14/16.

Growing Area and Planting

For field production, Lilies need to be planted in the spring when the danger of frost is gone. For greenhouse production lilies can be planted any time. Check with your agent or supplier to see which varieties are most suitable for the time of year that you would like to grow. Certain varieties perform better in the winter and others perform better in the summer.

Timing

Each cultivar has its own specific growing time. In general Asiatics and L.A. Hybrid varieties are quicker than Orientals. In the price list you will find the average amount of days it takes from start to finish. These statistics were based on new crop lilies planted in a greenhouse in Holland, where the day temperature is 67 F and the night temperature is 63 F. The timing of your crop can be sped up by raising the day and night temperature in your greenhouse. Subsequently the crop can be slowed down by lowering the temperature. Be careful when raising the temperature in the greenhouse, especially in the winter months. Additional light might be necessary.

Soil Requirements and Watering

Plant bulbs in a sterilized, well draining planting medium with a pH of 6.5-7.5, approximately 6 inches deep and 5 inches apart. Use wire mesh to help you as a planting guide or apply after planting. Wire mesh will be necessary to support the crop. Do not use city water that contains fluoride for irrigation. Fluoride toxicity can lead to scorch on your plants. Do not use a planting medium containing perlite or superphosphate. If signs of penicillin from storage are present on the bulbs, then the bulbs should be dipped prior to planting in a fungicide. You can use Captan or Cleary’s or a combination of Captan and Domain. Right after planting overhead irrigation can be used. Once the plants get up in size, drip irrigation is recommended. Water the planting medium thoroughly after planting and keep the medium moist but not wet.

Fertilizing

Fertilizing should start as soon as the plant is 6” tall. An application of calcium nitrate at a rate of 2 lbs. per 100 gallons once in three weeks is recommended. A slow release fertilizer like Osmocote 13-13-13 can be used as well.

Greenhouse

Use a high light greenhouse, with proper ventilation. Keep night temperatures at 63 F and day temperatures at 67 F. For forcing of lilies in a plastic greenhouse during the months of November through February supplemental light is recommended. You should use high pressure sodium lights for at least four extra hours every day. Make sure the crop stays dry at all times. Lilies are susceptible to botrytis, which usually develops when humidity is high. During the late spring and summer, 50 percent shade should be applied over the crop to cool it down and prevent scorch.