Planting tulips in Southern California is a matter of geography if you are to be successful. Tulip (Tulipa) bulbs are dependent on the weather and soil temperature, and Southern California experiences a wide range of temperatures from the mountains to the coast to the desert. The mountains and the desert experience cold temperatures in the winter, while the coast is wet and humid. Experiment with a soil temperature thermometer until you find a location where the soil temperature is below 55 degrees Fahrenheit when it's time to plant.
Preparing the Tulip Bulbs
Even if you live in the desert, tulips can grow if you take certain steps. The bulbs need a cold period where they chill for 12 to 14 weeks prior to planting. If the soil is too warm, you can fool your bulbs by putting them in the refrigerator wrapped in a mesh bag and stored away from fruits or vegetables. Place your bulbs in the refrigerator in mid-September and plant from mid-December to January.
Another trick to fool the bulbs is to plant them in a pot and chill the entire pot. This allows the bulbs to start growing roots. In four to six weeks, remove the pots, give them water and place them outside in partial to full shade. Spread organic mulch on top of the soil and water frequently to keep the soil temperature low.
Planting Tulips in Southern California
Southern California undergoes a multitude of weather changes throughout the year. Deserts get cold in winter, which is good for planting tulip bulbs. It also has a full rainy season beginning in January, and it's important that your garden bed doesn't become waterlogged.
Once the tulip bulbs have chilled or the soil has remained under 55 degrees for many weeks, you can plant the bulbs. Tulips need well-drained soil that has been enriched with organic compost. Adding nitrogen to the soil helps the flowers to develop. Plan your garden placement ahead of time in order to regulate the flowering display.
Starting in mid-December, plant some of the well-chilled bulbs. Plant more two weeks later and continue until all the bulbs are in the ground. This gives you a rotating display of color throughout the season. Bulbs that are shallow-planted bloom faster. For a continuous display, plant all the bulbs at the same time and at the same depth.
Should You Dig Up Tulip Bulbs?
Tulips are the first harbingers of spring, and their brightly colored flowers welcome the soft sunlight. They are also one of the first to die off, but digging up the tulip bulbs prevents them from emerging the following spring. Putting tulips to bed properly assures you of another year of flowers.
Once the flowers fade, pinch them off from the stem at the base of the flower. This keeps the foliage and stem intact without drawing energy from the roots. Allow the foliage and stem to wither and turn brownish-yellow. At that point, you can cut down the plant to the soil line to allow the plant's energy to return to the bulb and prepare for the next season.
Add a few inches of organic compost to the soil. Don't put it close to the bulb, as it can cause damage. Your tulip bulbs should reflower for several seasons, but if they don't, start all over again.