Prepare a planting site for brodiaea in full sun to light shade by loosening the soil to a depth of 8 to 10 inches with a spade or shovel. As with most bulbs and corms, the soil needs to be well-drained, so don't pick a spot that stays wet, such as near a downspout.
Plant brodiaea in the fall. Using a trowel or bulb planter, place each corm so that the bottom is 5 inches below soil level. Space the corms 3 to 4 inches apart. Brodiaea looks best when planted in large drifts or masses.
Feed the bulbs each spring with a fertilizer specially formulated for flowering bulbs. Follow the package directions carefully for the proper amount to apply, as the rate will vary depending on the product you choose. Some products also call for a fall application.
Water brodiaea only during extended dry spells. The plant is naturally drought tolerant so normal rainfall is usually sufficient.
Apply a loose winter mulch over the planting bed in plant zones 5 and 6 for extra protection. Apply the mulch after the plants have gone dormant, and clear away all withered leaves and other debris before mulching. Remove the extra mulch in the spring. Winter mulch is not needed in plant zones 7 and 8.
Harvest brodiaea flowers one to two days before the first flower bud in the cluster opens. Cut the flower stem at ground level, as new flowers will not form on any remaining stem. Flowers cut at this stage last as long as 12 days under optimal conditions. While each individual flower in a cluster lasts only three to four days, the flowers open over an extended period.
Fill a clean vase with water mixed with a cut flower preservative. Follow the package directions for the amount of preservative to mix with the amount of water your vase holds, and stir the mixture well to completely dissolve the chemicals.
Recut the brodiaea stems under water before placing them in the vase.
Change the water and preservative mixture whenever it begins to look cloudy or discolored, usually every three to four days. Recut the stems each time you refill the vase.