Italian cypress (Cupressus sempervirens) is a coniferous evergreen with tall, columnar growth habit. The tree has a moderate growth rate and grows 40 to 60 feet tall with a 3-foot spread. A number of reasons could be behind the discolouration of Italian cypress trees.
The browning of evergreens is commonly referred to as needle blight. Needle blights are caused either by poor growing conditions or pathogenic infections.
Sudden brown, red or purple discolouration of needles characterises needle blights. Symptoms start at either the tip or base of needles and gradually spread over the entire tree. Severely affected trees take on a general brown look.
Poorly irrigated trees that suffer from drought display symptoms of needle blight. Stressed trees are prone to winter injury and sunscald, which exacerbates discolouration. Fungal infections that lead to root rot disease are also a common cause of declining and browning evergreens. Trees growing at higher elevations are more susceptible to root rot.
Water trees well especially during periods of high heat. Mulching trees helps to preserve moisture in roots. Do not over water as this promotes the growth of root rot causing fungi. Apply a balanced fertiliser during spring.