Tulips can be considered one of the most popular cut flowers. It's appearance is associated by most people with spring. Tulips are available in many different varieties, colors and heights and can be used for cut flower production or container production.

Growing Area and Planting

For field production, Tulips need to planted in the fall when the soil temperature has dropped below 55 Fahrenheit. For Southern States (Zone 8-9) Tulips need to receive at least 6 weeks of pre-cooling prior to planting.

Tulips can be planted close together. For outside 4" centers is recommended. For greenhouse production Tulips can be planted on as little as 3" centers.

For greenhouse production Tulips can be forced according two different methods:

1) 48 Fahrenheit forcing. This method is generally used for container forcing. Plant tulips in the fall in containers and move containers into a rooting room @ 48 Fahrenheit (cooler). Keep the containers at this temperature until roots start growing out of the bottom of the container and the shoot reaches a length of 1" to 1 /2" tall. If the roots are visible and the shoot has not developed yet, the temperature in the cooler should be lowered to 41 F until the shoots are 1" to 1 1/2” tall. This process takes approximately 8 to 9 weeks. Once the Tulips have reached this stage, they can be moved into a greenhouse for finishing.

2) 40 Fahrenheit forcing. This method is generally used for cut flower production.

Your supplier will pre-cool the varieties that you want to grow at 40 Fahrenheit. After this period, the bulbs can be planted in ground beds in the greenhouse or can be planted in trays and moved into the greenhouse right away. The earliest you can start planting according to this method is around the second week of December. Once planted, it will take approximately 6 to 9 weeks until flowering, depending on the variety. Plantings of pre-cooled tulips can be done on a weekly basis until early to mid February. The forcing time on late plantings will be shorter than the early plantings.

Timing

Tulips that have been planted in containers and are started in the rooting room will only take 3 to 4 weeks to finish, once they are moved into the greenhouse (see 48 F forcing).

Flowering on these tulips can be delayed by storing trays or containers at 34 F prior to moving into the greenhouse. Tulips can be held for up to 3-4 weeks to delay the flowering time. To speed up the flowering time, you will need to raise the temperature in the greenhouse. Do not let the temperature exceed 70 F, in order not to sacrifice the quality of your flower.

Tulips that have received their full cooling period from your supplier and are planted as of the second week of December take 6 to 9 weeks until flowering (see 40 F forcing).

Flowering time on these plants can be delayed by lowering the day and night temperature, as long as the night temperature does not go below 36 F. To speed up the flowering time the temperature in the greenhouse will have to be raised.

Soil Requirements and Watering

Plant bulbs in a sterilized well draining planting medium with a pH of 6-7, approximately 3 inches deep. Dip the bulbs prior to planting in a fungicidal solution to prevent disease problems. You can use Captan, Cleary's, Domain or a combination of these fungicides.

After tulips are planted, it is recommended to top dress the growing medium with a thin layer of half an inch of heavy sand. Tulips make a very thick but shallow root system. The sand prevents the bulbs from pushing themselves up out of the growing medium.

After planting, water the containers or beds really well. Once growth appears, the soil needs to be kept slightly moist. Irrigate plants in the morning , so the crop can dry during the day.

Fertilizing

Fertilizing should start as soon as the plant is 3" tall. An application of calcium nitrate at a rate of 2 lbs. per 100 gallons on a weekly basis is recommended. Calcium nitrate will help to prevent stem topple, which is a physiological disorder associated with greenhouse forced tulips.

Greenhouse

Use a medium light greenhouse, with proper ventilation. Keep night temperatures at 55 F and day temperatures at 65 F. You can use drip or overhead irrigation. Drip is preferred when bulbs are planted close together.