Holly shrubs, also known as Ilex, are flowering perennials valued for their ornamental berries and glossy, evergreen or semi-evergreen foliage. Native to North America, holly shrubs are hardy in USDA zones 5 through 9, making them ideal for all but the coldest regions of the U.S. Holly shrubs flower during summer, though their green and white flowers are considered inconspicuous, and most varieties keep their foliage year round. Holly requires only minimal care to thrive and produce berries year after year.
Plant holly shrubs during mid-spring after all danger of frost has passed. Choose a site that receives full sunlight throughout the day and consists of rich, fertile and well-drained soil for optimal berry production. Space holly shrubs 3 to 12 feet apart, depending on the variety.
Spread a 2- to 3-inch layer of organic mulch over the soil surrounding holly shrubs to insulate the soil, deter weeds and improve moisture conservation. Allow at least 3 inches between the crown of the plant and the mulch to provide room for air circulation. Replenish the mulch as often as necessary throughout the growing season.
Water holly shrubs thoroughly once each week to keep the soil consistently moist. Apply water directly to the soil to avoid splashing water on the foliage, as moist leaves are more susceptible to pests and fungal diseases.
Feed once each year during early spring, just as new growth begins. Fertilize using a granular 10-10-10 NPK fertilizer to provide proper nutrition for berry and root formation. Water thoroughly after applying to release the nutrients into the soil. Apply at the rate described on the package for the best results.
Prune holly shrubs once per year during late winter, just before active growth resumes. Use pruning shears to remove all leggy, bare, overgrown and damaged limbs from the plant to increase both visual appearance and overall health.