How to grow Hypericum

Hypericum is  also known as Rose of Sharon and St John's wort. It is a deciduous summer flowering shrub grown for its lovely bright yellow flowers and followed in autumn by attractive berries. It is an evergreen or semi ever green depending on where it is grown, and will shed its leaves when grown in colder areas.

Hypericum is easy to grow being tolerant of most growing conditions and it tends to be vigorous. Hypericum will put up with drought and shade, (although flowers best in sun) but dislikes waterlogged, damp soils. Hypericum has a long flowering season and carries a profusion of blooms as the image top right illustrates. There is no need to prune other than to remove any dead wood in the spring.   There are several varieties with different growing habits : Hypericum  Calycinum is a low growing spreading type, only 60cms high and is good for grown cover. It will spread quickly, quite vigorously, and is bordering invasive and each plant will spread up to 1.5.  Hypericum Inodorum Elstead is quite different,  upright and bushy up to 1m with 1m spread.

Hypericum Hidcote image left is a very popular variety which has RHS garden merit award and grows up to around 1.2m so suitable for the back of the border and even for hedging.

There are also dwarf varieties suitable for front of the border or rock gardens such as Pallens

Another plus point of Hypericum is that it is ideal for cut flowers both the blooms and later the berries. 

 For an explanation about frost hardy

How to prune Hypericum

It is  essential to prune Hypericum but if needed spring is the time to take the shears to it.

A light prune in early spring if you want to restrict size or tidy up. Some Hypericum are prone to rust and pruning in the spring is one way to remove rust tainted branches. Hypericum also self seed quite a lot which is a plus or minus depending on what you want in your garden.

To reduce the problems with rust the shrub can be cut down at the end of summer and all the rusty leaves removed for a fresh start in the spring. It will still flower and produce berries as Hypericum flower on the current years wood. In particular H. calycinum which is vigorous and can be prone to rust so  will benefit from being cut back annually to the ground in around february /March time. Generally Hypericum flowers from July to October.

Fully ***hardy and easy to grow. Most Hypericum need little or no attention and grow in almost any conditions.

Last updated 09.01.2020