Spring-flowering bulbs must be planted in the fall because they require a sustained "dormant" period of cold temperatures to stimulate root development. It is recommended that bulbs be in the ground six weeks ahead of the first hard frost, normally mid to late November. As a general rule, in Tulsa, they should be planted in mid-September to mid-October. (TULSA FREEZE Information).
Bulbs should be planted as soon as possible after bringing them home. If you must store them, keep them dry and cool between 50° and 60° (F). For long storage periods, a refrigerator vegetable compartment can be used, but be sure to keep them away from ripening fruit. The ethylene gas emitted by fruit's ripening process can destroy bulbs.
In addition to tulips and daffodils, you'll also want to plant other exotic Dutch bulbs, such as spring-flowering scilla, puschkinia, muscari, fritillaria, allium, camassia, and eremurus.
The Tulsa climate will affect which bulbs you choose to plant. Not all bulbs have the same cold requirements. Ask your bulb supplier to recommend the flower bulbs that do well here. The USDA publishes a climate zone map covering the entire U.S. This can be found reproduced in many gardening books and magazines.
Spring-flowering bulbs offer a wide variety of colors, heights and flowering periods.
Much of the information you need to plan your garden is written on the package, or available from your bulb supplier. These include:
To determine how deep to plant and spacing see Bulb Planting Guidelines. In general, consider the caliber or size of the bulb, large bulbs (2 inches or more) are usually planted about 8 inches deep; smaller-size bulbs (1 inch) are planted 5 inches deep. Space large bulbs 3-10 inches apart and small bulbs 1-2 inches apart.