Crocus Experiments

Light

• Crocuses are among a group of flowers that open their petals during the day and then close them at night. One theory on this phenomenon holds that these flowers open during the day to attract bees and butterflies, which assist in pollination, while closing at night to protect their petals from nocturnal predators and to keep their pollen safe. Replicate this process during the day by covering a crocus flower with a shoe box to prevent the light from reaching it. Observe the petals of the flower before covering it with the box, then see whether the flower petals close after five minutes in darkness. Try covering the flower for different intervals to see whether the length of time in darkness changes the outcome.

Forcing

• Like bulb flowers, crocuses must endure a period of cold to bloom in the spring. For this reason, crocuses and bulbs such as tulips are typically planted in the fall when temperatures begin to drop. The warmer temperatures of spring signal the dormant plant to begin growing. You can force a crocus to grow out of season by controlling the light and temperature to which it is exposed. Plant a crocus bulb in a pot, then place the pot in a refrigerator or a dark area with a temperature of about 38 degrees Fahrenheit. Once you observe growth from the bulb, move the pot into a warmer area --- about 58 degrees Fahrenheit --- that gets indirect sunlight. This experiment will take several weeks to accomplish.

Compare With Other Bulbs

• Build on the previous experiment by observing how crocuses in different conditions behave, and compare your observations with how other bulb flowers behave in different temperatures and light levels. Plant several crocus bulbs in pots, and choose at least one other bulb flower, such as tulips, to plant. Place some of the crocus plants and some of the tulip plants in a refrigerator or cold area, and place the remainder on a sunny, warm window sill. Observe the plants for up to two weeks, and note any changes. After two weeks, move the plants from the cold area to the window sill and observe the similarities and differences between the plants.

Bulb position

• Bulbs prefer to be planted right side up for optimal growing. Conduct an experiment to see what happens when you don't plant a crocus bulb right side up. Plant one crocus bulb upside down in a pot, and observe whether or not it grows. Try planting one bulb sideways. Plant at least one bulb right side up as a control, and compare your results with the bulbs planted sideways and upside down. Observe whether the different positions affect the time it takes the bulb to sprout and grow.