Leylandi Conifers have gained certain notoriety over the years for their incredible growth rate. These Shrubs can grow up to a meter a year and is sometimes referred to as the "hedge from hell." There are so many issues with these conifers that there is actually a law covering their usage in the UK. Many landscaping businesses and Nurseries will not carry the plants now because of these laws.
For many years, this cross between the Monterey Cypress and the Alaskan Cedar was extremely popular at Nurseries and made up around 10% of sales for some time.
As the problems with these Shrubs became more evident, they dropped in popularity. While still popular with anyone looking for some serious privacy, the Trees are no longer planted in many areas and people are actually removing them from their gardens and property lines.
In the UK, there is a law that is known as the Leyandi Law, though the official name is Anti-Social Behaviour Act 2003, Part VIII. It offers help to those who are affected by Extra Tall Hedges which may block the light to their garden. Now authorities can check the Hedges in question and decide if they need to be cut down or not.
There are several reasons to avoid Leylandi Conifers, even for use in Hedges. The main reason is that they grow insanely fast and can reach up to 35 meters in height. This can cause problems with the neighbours as these are very thick growing Trees and they can block out the sun, completely obscuring a neighbour's garden and causing thousands of disputes. At least one person has even been murdered over problems with the Hedges.
The roots of these Trees tend to be shallow, but they can spread quite far, especially in taller trees. This may cause any number of problems, including drying out the ground where the roots are, as they suck up the moisture. Without adequate water, the Shrubs can take all the moisture and leave grass and other plants wilting and dying. This is particularly problematic when the roots cross the property line and dry out the area on the other side. As the Hedges are usually planted on property lines, it's easy to see how this can cause rows between neighbours.
Another issue is having the Leylandi Conifers too close to buildings. The roots can damage foundations and in some areas, they are actually banned from being planted in smaller gardens where reaching the foundation is inevitable.
If you have a Leylandi Hedge on your property, it can be difficult to get rid of and usually requires professional services. The Shrubs may be poisoned, but perhaps the best way to ensure that they are removed completely and safely is to simply cut them down. The stumps can be removed later and it is unusual for a conifer to grow back from a stump.
Leylandi Conifers can be a real challenge, as evidenced by today's UK law against their overgrowth. It can be very expensive to maintain them, as well, as the Hedges and Shrubs need constant attention and trimming to keep them to a decent size. Landscaping Companies can usually remove them for you.