Illicium is a plant genus that is part of the Illiciaceae family. It contains about 40 species of evergreen trees and shrubs that are native to the Americas and the West Indies. Most of the species feature unique starry shaped flowers and dense shiny foliage. They are excellent specimens for woodland gardens and borders. A problem commonly encountered in the garden regarding this genus is root rot, which is a fungal infection.
Gardeners select shrubs from the Illicium genus for a number of reasons. The most obvious is the thick foliage, which provides good shade and acts as a privacy screen for windows. Another appealing quality of most species is the aromatic scent they release. Also, the shrubs produce flowers that are rather unique. Illicium floridanum in particular features maroon to purple flowers that have 20-30 strap-like petals.
Plants within the Illicium genus are used in a variety of ways in the garden. Taller species that reach a height of 30 feet (9.1 m), such as Illicium parviflorum, are generally used at the corners of a house. Shrubs that are 6-12 feet (1.8-3.7 m), such as Illicium floridanum, can be planted with similar sized shrubs in borders or cut as hedges. Smaller species are typically grown in containers or in cool greenhouses.
Ideal growing conditions will allow the shrubs to grow properly. Usually, a well-draining soil that is rich in organic material is required for optimum growth. It is recommended that the soil be slightly acidic as well. The area in which the shrubs are planted should have an adequate exposure to sunlight. Some species prefer the shade and will fade if exposed to too much sunlight.
Most species of Illicium are propagated by seeding or cuttings. The cuttings should typically feature the prior season's growth. It should be taken in the early morning and stored in a cool, wet environment before placing into a growing medium.
A common problem among shrubs of this genus is fungal infections. Anthracnose is a fungal disease which affects the leaves, stems, flowers, and fruits of a shrub. Signs of infection include sunken lesions that are black or brown tissue that is curled or distorted. Another fungal infection to worry about is root rot, which is caused by a fungus. It damages the roots of the shrub, preventing the absorption of nutrients. Eventually, the leaves begin to yellow and fall off.
The risk of infections can be reduced with proper soil conditions and watering techniques. Avoid overhead watering, which tends to splash fungal spores to other areas. Also, remove plant debris from the underbrush to prevent overwintering spores from becoming active the following season.