Japanese maples, prized for their stunning seasonal colour transformations and uniquely shaped foliage, require careful summer care to avoid dieback. According to gardening expert Roger Eavis, owner of Greenshutters Garden Centre, the single most important task is maintaining consistent soil moisture. "Keep the soil or compost well-watered and never let them dry out," Eavis advised. "If the leaves on your Japanese maples appear dry or scorched in summer, this is likely to be a lack of moisture. This is, by far, the main cause of dieback."
Watering Frequency and Technique
Eavis recommends watering Japanese maples once a day during hot weather if they are in a pot, and two or three times a week if planted in the ground. "Most Japanese maples will grow happily in direct sun if they are kept well-watered," he explained. "If not, plant them where they will get shade for part of the day." Gardeners should adjust their watering schedule based on changing weather conditions, increasing frequency during extreme heat or extended dry spells, and reducing it during heavy rainfall to prevent waterlogging.
Checking Soil Moisture
Regularly monitoring soil moisture is essential. Eavis suggests pushing a finger or a moisture meter one to two inches into the soil. If it feels dry at that depth, it is time to water. This practice helps protect against both under- and overwatering. Japanese maples thrive in consistently moist conditions but can suffer if overwatered.
Deep Watering for Strong Roots
When watering, it is crucial to give Japanese maples a thorough, deep watering. For trees planted in the ground, this means several minutes with a hose or longer with a sprinkler. Deep watering encourages roots to grow further down, making the tree more resistant to drought. For container-grown Japanese maples, water until you can see it draining from the bottom of the pot, ensuring the entire root system receives sufficient hydration.
Best Time and Method
The time of day also matters. Watering first thing in the morning is optimal, as it allows the trees to absorb moisture before the heat of the day sets in, minimising evaporation. Always water directly at the roots, as Japanese maples only absorb water through their roots; watering the leaves serves no purpose.
Benefits of Proper Care
Maintaining moist soil will keep the tree "healthy and vigorous all summer," according to Eavis, and they "will reward you with incredible autumn colours." By following these simple steps, gardeners can ensure their Japanese maples remain vibrant and avoid the risk of dieback.
