Japanese Maples (Acer palmatum, Acer shirasawanum, Acer japonicum, Acer sieboldianum being the most well-known) have the rather unfair reputation of being hard to grow and this simply isn’t true if you follow a few simple guidelines.
- They don’t require acid soil to grow and will be perfectly happy on most good soils. Just avoid very chalky soils and areas that get waterlogged or incredibly dry.
- They don’t have to be grown in the shade – almost all cultivars will grow well in a sunny position. Those that are variegated or with pale yellow foliage will benefit from some shade during the hottest part of the day. Purple leaved types need at least half a day of full sun to maintain strong colouring.
- Never over-pot a young tree and only ever re-pot if the root system is well developed and holding together well.
- The best time to re-pot is early spring, just as the tree is coming in to leaf. They don’t require ericaceous compost but be sure to use a good quality, free-draining compost. We use a peat-free multipurpose compost mixed with composted bark which helps maintain an open soil structure. Air in the compost is just as important as moisture.
- Ensure the compost stays damp (but not soaking wet) throughout the growing season – consistency is key! As with any tree, the larger and more mature it is, the more tolerant it will be of erratic watering. However, do remember that the better you treat the tree, the better it will grow and reward you for your kindness…
- Young trees grown in pots will benefit from being moved somewhere reasonably sheltered from the worst of the winter weather.
- Japanese Maples grow very well in containers and with the right care can be happy for many years (think Bonsai). Having said that, they will always grow better in the ground; they have access to everything they need (water and nutrients). In a pot they are always reliant on a third party (you!) to remember to water or feed when necessary.
- We recommend seaweed fertiliser as a feed – it contains all the normal stuff plus a whole heap of trace elements for excellent growth. Don’t overfeed – once or twice a year is plenty for strong growth.
- When planting in the ground, we strongly advise the addition of Rootgrow Mycorrhizal Fungi Planting Powder – this will create a symbiotic relationship with your Japanese Maple which will last its lifetime, making it a healthier and happier tree. In fact, the fungi make the roots so efficient that fertilizer is not required.
- Ensure the tree is watered well for its first season – until it is has established its root system. It is better to give it a good soak once a week or so during dry weather than just a little every day.
- Whether planting in the ground or in a container, please ensure that you don’t plant too deeply. Look closely at the base of the trunk and you should be able to identify where it starts to widen – this is known as the root flare and should be the finished ground level. If a tree is planted too deep, soil will be in contact with the trunk which can promote fungal diseases and attacks by pathogens.
I hope this has helped and answered more questions than it has posed! Please feel free to email or call us if you would like any further advice. Good luck!