• Wear garden gloves when handling common rue.Hemera Technologies/PhotoObjects.net/Getty Images
  
  Common rue (Ruta graveolens) is a perennial herb that grows to a height and spread of 3 feet. Its attractive, blue-green compound leaves make it a good plant for row hedges. Though it can be quickly propagated from stem cuttings, common rue can also be propagated by seed, and will freely seed itself through a garden. Wear gloves when handling common rue foliage and stems. This plant is toxic, according to Cornell University, and contact with skin can cause irritation.
  
  

Seed Size and Appearance

• Watch for common rue to flower in midsummer, if it's been planted in partial to full sun, in deep, sandy soil. It may not flower if conditions are not right. Rue flowers are inconspicuous, small and yellow. As blooms fade, fruit with four small husks develops and seeds ripen inside. They are tiny, half-moon shaped and yellowish brown.
  
  

Seed Dispersal

• Common rue seed husks burst open in fall. They'll turn from summer's green to brown and brittle as they dry out. Seed is broadcast by the force of the husk breaking open, dispersing seeds a good distance from the mother plant. Collect husks before this happens if you wish to collect the seeds.
  
  

Seed Germination

• To control the spread of common rue, collect seed husks before they burst open. In outdoor conditions, seed will lie on the ground over winter, undergoing a process called cold stratification, which helps them germinate. You can imitate this process indoors by storing seed in a paper envelope in your refrigerator. Seed can be sown outdoors in spring, after the last frost is past. Simply scatter seeds on top of moist, well-drained soil, covering them with 1/4 inch of additional soil. Viable common rue seeds will germinate and sprout within two weeks.