June advice from the Head Gardener

How to grow Eryngium

It’s fitting that as I write this Chelsea Flower Show is in full swing. Every year it seems a trendy plant is “discovered” at Chelsea, and Eryngium was just that about a decade ago. In spite of looking exotic it’s a native plant that has been with us for centuries. You may know it as “sea holly.”

The Eryngium has earned its place where form and colour are important, and does well if it gets full sun in excellent drainage. Bees love it. As an umbellifer it has a long tap root so it doesn’t enjoy being moved. There are many varieties with different heights and flower forms, but it’s fair to say they are generally blue, spikey and love the sun.
Although it’s got no scent to write home about bees love it so the blue we like must look good in ultra-violet too.

The plants in the photo are a hybrid that is very blue and about 50cm high. The blue colour gets brighter the more sun the plant has. This isn’t a plant for a shady corner so we have ours in a well-drained, walled garden. We use the colour to as a foil to lead the eye into a long border with sumptuous dark wine colours, bright blues and hot reds. You can see the tower in the background so if you are familiar with the Garden House you’ll know where the borders are!

This plant is a hard worker and if you can keep it warm and well-drained it will even seed around. Let the seed grow where it lands (it’ll be the following spring) and then move the young plants before they get too established.

In spite of the cold start to the season the garden is leaping on now and it’s a pleasure to work in it every day. Next month I might put pen to paper to give advice about wildflower meadows as I think it is going to be an extraordinary year for them.