Speed of leylandii growth

Leylandii, also known as Leyland cypress trees, are the fastest growing conifers. In the early years of this plant, it’s not unknown for the tree to grow between 45cm and 90cm in height per year. Of course, this depends on the leylandii having the best growing conditions possible.

Over its lifetime, this Leyland cypress can grow to about 18m to 21m high. This tree is dense, with a broad column at the bottom tapering to a narrow pyramid at the top. If you have plans to keep your cypress tree to a certain height, you must consider the need to regularly prune it to your required shape and height. Especially if you want to use it as a hedge.

Learn more about when and how to trim leylandii here

Different varieties of leylandii do have different growth rates, however. Green Leylandii and leylandii 2001 grow up to 90cm a year; Leylandii Castlewellan Gold grows as much as 75cm a year; while Leylandii Gold Rider is relatively slow growing at just 45cm a year.

Leylandii best growing conditions

Here’s a summary of the growing conditions that keep your leylandii growing fast and strong.

• These plants need full sun and protection from winds.
• They need to be staked down for their first year of growth, usually, they come with canes already in them.
• Fertilise them for the first year. Consider using a controlled release fertiliser that lasts for 12 months.
• They don’t need fertilising after their first year; their root system gets its own nutrients from the soil ad they can thrive in poor soils.
• Larger leylandii plants establish themselves quicker than smaller ones.
• Start pruning the plants when they’re young. Trim the sides every summer, maybe 2 or 3 times a year once established.
• Always leave green growth on the sides of the plant; leylandii doesn’t grow back from old wood.
• Leave the tops of a leylandii hedge until it’s within 15cm of the height you want; then trim them off so they branch out and form the top of the hedge.

Also, learn how to stop leylandii from growing in this guide as well as how far leylandii roots spread here, handy to know when planting next to a house or wall

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