GARDEN GURU

Q

A plant has appeared in a border. It’s at least 5ft tall, with large furry leaves and tiny yellow flowers. Do you know what my mysterious visitor is? Janice Jeans

A

The picture you sent to me shows common mullein (Verbascum Thapsus), a stately biennial wildflower with blooms that are loved by pollinators. It likes a sunny spot and freedraining soil. Sadly, the entire plant will die after flowering but it will self-seed.

Q

Sedum plants are gradually taking over my rockery. How can I get rid of them?

Patricia Tarleton

A

I assume you mean Sedum acre or stonecrop? Often sold as an alpine for rockeries, it can be pretty invasive if it finds conditions to its liking. The best way to control unwanted populations is to fork up clumps, making sure you sweep up any leaves that fall off in the process to prevent them regenerating. If the problem is severe, it may take several years to stamp out.

Q

My recently planted hydrangeas are growing well and forming flower heads, but are developing some yellow leaves. Should I be concerned?

Maggie Jackman

A

The leaves shouldn’t be turning yellow if it’s just been planted. It’s most likely due to a nutrient deficiency, so perk it up with a dose of Westland Hydrangea High Performance Liquid Plant Food.