Perennial in mild climates; grown as annual in cold zones. Allelopathic — inhibits growth of many vegetables, especially tomatoes and beans. Best planted in isolation or at garden edges. Highly attractive to swallowtail butterfly larvae and beneficial insects. Direct sow; taproots resent transplanting. Self-seeds freely. Both foliage (herb fennel) and swollen bulb (Florence fennel) are edible.

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