Hydrangeas can be protected from cold weather damage by spreading fallen leaves around their base, a simple and free method shared by gardening expert Jessica Walliser from Savvy Gardening.
As autumn arrives, hydrangeas may be fading, but there is one task gardeners should still do now to help ensure they bloom beautifully next year. October usually brings mild enough weather for small garden jobs, but in the next few weeks, the first frost will appear in some parts of the country.
This can put a lot of stress on hydrangea roots, as they are close to the surface and more exposed to harsh weather. If the roots are constantly exposed to the cold, they can become damaged, and once spring arrives, the plant may struggle to grow flowers or even start to die back.
Why mulching helps hydrangeas in winter
Mulching is a gardening practice of placing material around a plant to create a natural barrier that protects it from extreme weather. Gardeners use mulch once it gets cold to protect the ground around plants from constantly freezing and thawing, which can cause significant cold damage by overloading the soil with icy water.
Jessica said: “Fall mulching of hydrangeas leads to well-insulated roots that can better survive weather extremes and the ups and downs of freeze-thaw cycles.
“Do not over-apply mulch (two to three inches is plenty), and do not pile it up against the plant’s base or trunk. Make a doughnut shape of mulch around your hydrangea. You can also use shredded fall leaves for this job.”
Using leaf mould as a natural mulch
Autumn is a great time to mulch hydrangeas, as it will not just start to get colder, but there will also be a lot of leaves on the ground, which can be used to create leaf mould. Leaf mould is a good choice of mulch for hydrangeas, as it insulates the roots, helps prevent temperature fluctuations, and helps prevent the ground from freezing constantly.
It will also add a lot of nutrients to the soil while still being a gentle material, helping keep the roots healthy throughout winter so the plant produces many beautiful flowers next spring.
How to make and apply leaf mould
Using leaf mould is a natural and no-cost way to help hydrangeas, but the only drawback is that it can take a long time, so allow enough time for the leaves to break down. You can easily make it yourself, but you can also buy leaf mould mulch in most gardening centres if you want to use it now.
To make it, collect any fallen autumn leaves and place them in a large plastic garden bag. Poke holes in the sides and bottom of the bag to create drainage. If you wish, you can also use a compost bin, but leaves take longer to break down than normal compost, so it helps to have a different bin for your leaf mould.
It can help to shred the leaves with a mower before placing them in a container. Then, leave the bag or bin somewhere in your garden, preferably damp and warm, as this will help speed up the process.
Once you have your leaf mulch, spread it in a circle around your hydrangeas, around two to three inches deep into the soil around the root area. Mulch can retain a lot of moisture, so do not pile it up or let it touch the hydrangea stems, as it can overload the ground and cause rot. Spread it a few centimetres away in a doughnut shape, and top it up occasionally when the mulch starts to look thin.
This mulch should be enough to protect a hydrangea once the cold weather begins, so gardeners do not have to worry about the plant becoming stressed or damaged in winter.
