It may seem obvious to fertilise the garden in summer to encourage lusher foliage and vibrant flowers, but this can seriously harm Japanese maples. These beautiful trees are highly sensitive to the heat, and fertilising during hot weather can burn their roots, which will weaken or even kill them.
Michael Francis from Japanese Maples and Conifers has shared now in June is far too late to fertilise these trees, but there is another way to help them stay healthy and grow stronger. He said: “Mulching is a vital practice for retaining soil moisture and regulating soil temperature. One of the most effective ways to ensure your Japanese Maples thrive during the hottest months is through proper mulching.”
Mulching is the simple gardening practice of adding a layer of material on the soil around plants to protect them and add more nutrients.
Mulch is far slower than fertiliser as it takes a long time for organic matter to break down, so it has no chance of harming Japanese maples.
However, the real reason you need to mulch your Acer trees is that mulch holds a lot of moisture and reduces evaporation, keeping Japanese maples hydrated no matter how hot it is.
Japanese maples have shallow roots which tend to dry out quickly in the summer, and mulching helps them retain more water, so they keep growing and do not become stressed.
If you do not mulch Japanese maples, they are more likely to become stressed out by the extreme heat, which can cause their leaves to turn brown, burn and even shed.
This means you will not get a beautiful looking tree in autumn with brilliant red leaves, but rather a bare and scorched plant that is struggling to survive.
How to mulch a Japanese maple tree in summer
Mulching is very easy, as all you need is to pour a thin layer of organic mulch around a Japanese maple tree, but leave some space around the base.
Mulch contains a lot of water, which is great for the soil, but too much around the trunk can smother the roots and encourage mould, pests or even disease.
Michael said: “Apply a one to two-inch layer of organic mulch, such as pine bark or pine straw, around the base of the tree.
“Avoid piling the mulch too thickly, as this can lead to poor air circulation and moisture buildup.”
Japanese maples love pine bark, and straw is long-lasting, allows more air flow, and can keep the soil watered to help boost this delicate tree.
Make sure to give your Acer a good watering after mulching, and then keep checking up on it throughout the summer. It should bloom beautifully once autumn arrives in a few months.
