The hybrid Cupressocyparis leylandii, known as the Leyland Cypress, is a fast growing evergreen tree used for screening, hedges, and even Christmas trees. Prized for the ability to grow 3 to 4 feet per year for the first years of life, the Leyland Cypress is capable of heights in the 100-foot range and spreads to 20 feet easily. The concern for this soft needled, blue-green giant is typically how to control, rather than induce, rapid growth. However, in order to get the maximum height possible in the shortest amount of time, consider location, pH levels, soil preparation, mulching, watering and fertilization as methods to reach these mammoth heights.
Choose a location with full sun to part shade. Allow adequate space for the massive size these evergreen trees will attain. Well drained soil is preferred, so check for drainage prior to planting. Dig a hole 6 inches deep. Fill with water and check the hole after 4 hours. If the hole is empty, the site has adequate drainage.
Check the soil pH with a test kit purchased from a local garden center or your local university extension office. A range of 5.5 to 8.0 pH is acceptable for the Leyland Cypress, with 6.0 to 6.5 being the optimum target. Amend soil if necessary according to kit recommendations, or those of the university extension experts.
Prepare the soil for long term growth by tilling 3 inches of organic matter, such as composted pine bark, into the soil. Incorporate to a depth of up to 1 foot across the bedding site, which should be several square feet beyond the planting hole area.
Plant the evergreen with the root ball just below the surface, and firm the soil with your foot or hand without compacting it around the roots. Spread 3 inches of organic mulch, such as partially wood chips, around the planting area. Do not allow the mulch to rest around the trunk, as this practice can encourage disease.
Water the young Leyland Cypress during times of low rainfall to encourage root development and growth.
Fertilize only if the cypress is not growing at the robust 3 to 4 feet per year rate. Over fertilization is not helpful and may damage the growing tree. The University of Minnesota Extension experts suggest that If you do fertilize, do so in early spring with a balanced liquid fertilizer applied through a root feeder. Results will vary depending on the type of soil you have, and additional applications may be necessary.