Japanese Maples are known for their vibrant spring foliage, but gardeners should be aware of a common mistake that can often prove fatal to these beautiful trees during this season. Mike McGroarty, a gardener and founder of Mike’s Backyard Nursery, has warned that most garden fertilisers can kill your Japanese Maple tree, so it is important to be very cautious about what you add to the soil.
He said: “The typical garden fertiliser that you buy for your veggie garden will take out ornamental plants like nobody’s business. If you plan to use regular garden fertiliser on your Japanese Maple, you might as well write ‘serial killer’ on the bag.”
Japanese Maple trees have delicate root systems, and most fertilisers from garden centres can burn the roots due to their high nitrogen content.
While nitrogen is essential in spring for promoting healthy foliage growth in many plants, most commercial fertilisers release this nutrient too quickly, which will harm the tree.
Using these fertilisers can cause the tree to grow too quickly, resulting in weak, brittle growth that will easily become damaged and more likely to break off in the wind.
Too much nitrogen too quickly will burn the tree and result in leaf burn, which will lead to the leaves turning yellow, eventually falling off, and the Japanese Maple will likely never recover.
Mike explained: “Garden fertilisers are designed to be immediate-release. A bag of 14-14-14 garden fertiliser contains 14 percent nitrogen, 14 percent phosphorus and 14 percent potassium.
He added: “Nitrogen drives top growth, vegetative growth, on plants. Most ornamental plants physically cannot grow fast enough to use that much nitrogen, and the overload of nitrogen will kill them almost immediately.”
If you wish to feed your Japanese Maple properly, then add organic mulches like compost ot cow manure to the soil to enrich it, as this mimics the natural feeding process of these trees in the wild.
Mike said: “For years and years, vegetation falls to the earth and rots and becomes topsoil. That’s what all plants, especially Japanese Maples, need.”
If your garden soil is lacking nutrients, you can add fish emulsion, a slow-release fertiliser naturally rich in nitrogen, which provides a gentle source of nutrients without harming the roots
Japanese Maples also love millorganite, a non-burning organic fertiliser but be aware it should not be used on garden crops like fruits or vegetables as it is made out of treated sewage sludge.
However, be careful not to bury a Japanese Maple with too much organic material, as they only need a light coating. Too much can smother the tree and prevent oxygen from reaching the roots.
The best way to fertilise a Japanese Maple is with natural products, but if you are unsure, it is perfectly fine to skip feeding altogether, as this sensitive tree does not need any fertiliser to stay healthy
AloJapan.com