Question
The trees around my garden have started to go brown mainly on the inside. This is spreading through the trees, there is still top growth. Is there any cure for this ?

Answer
Sounds like a needles disease-Cercospora needle blight

Caused by the fungus Cercosporidium sequoiae (syn. Asperisporium sequoiae; Cercospora sequoiae), is a relatively new disease on Leyland cypress. However, it a common disease on species of Juniperus, Thuja, Cupressus, Taxodium, Cryptomeria, Sequoia and other genera. The first symptom of Cercospora needle blight is a browning of the needles in the lower crown next to the stem. The disease slowly spreads upward and outward until, in severe cases, only the needles at the tips of the upper branches remain green. In a general way, these symptoms mimic those caused by severe stress where the interior needles turn yellow and fall off. Fruiting bodies of the fungus appear as tiny, greenish pustules on the upper surface of the needles or on small twigs. Spores (conidia) are present throughout the spring and summer and are spread by wind. Infection usually occurs during long periods of wet conditions.

Cercospora needle blight can be controlled by spraying with copper-containing fungicides. There are no fungicides registered specifically for the disease on Leyland cypress, but Kocide is registered for general use on ornamentals. Spray plants at 10-day intervals from bud break until new growth starts.