Should I prune my Japanese maple?

Yes. Often young maples produce quite strong growth, and even dwarf varieties when young produce strong, out of character growth. In general these can be pruned back by two-thirds to produce a more balanced shaped tree. Again, always trim back as closely as possible to just above a pair of buds

Why is the foliage on my maple going crispy around the edges?

In spring this can be caused by light frost damage, often caused by the tree coming into leaf too early. You can often avoid this sort of damage by siting your maple away from too warm or sheltered position during winter, which can help prevent the plant from leafing out too early. Don't worry though - your plant will make a full recovery providing any stem damage is trimmed off.

In summer this can often be caused by water stress, either too much or too little. This problem only usually occurs in plants in containers or newly planted plants in the ground.

Too little water will cause some root damage, this will concentrate the sap around the edges of the leaves and as the plant cannot replace the moisture it is losing through the leaves so efficiently it reduces its leaf size by aborting the edges. Occasionally complete defoliation occurs. In an otherwise healthy plant it can make a full recovery and produce new foliage if it has time.

Too much water will damage or rot the sensitive roots, leaving the plant with a smaller root system unable to support its leaf canopy. However, by careful attention to water requirements in container grown plants you can ensure that this problem rarely occurs. Also, the older the plant becomes it is far more able to cope with erratic watering. Over watering should never a problem in a free draining container with free draining soil - which are the conditions that Japanese Maples thrive in.

Why has my maple got black dieback on the branches?

This is nearly always a bacterial dieback, (it is rarely Verticillium wilt). This condition can first be seen as a dark or black lesion along or around the main branches. As it is caused by a bacterium, treatment by fungicide is useless. The immediate pruning out of the infected area is the only method of control we have found to be effective. Always cut back to just above a pair of buds or side branch down to green, healthy wood. Sometimes this pruning has to be fairly drastic but the good news is that your lovely tree will make a full recovery if this condition is caught and treated early enough.

Dieback can also be caused by soft, unripened growth getting frost damaged during the winter. This growth has been made late the previous season and not had enough time to ripen off before the onset of winter. This is more common in container grown plants that have received too much nutrient at the end of the season. Prevent by pruning out soft, sappy growth in October before it has time to be damaged by the frosts of winter.

Light dieback can often be seen in some varieties of Japanese maple that produce thin, twiggy growth. This is a natural occurrence, which, if left unattended can become unsightly. A few minutes of breaking off this silvery-white dieback will enhance the look of your maple and ensure there is no opportunity for infection to occur. This can be carried out any time but is more easily done in the winter.

Why has my maple got two different types of leaves?

If the growth is coming from the base of the plant then this is a sucker. It is simply a branch that has grown from the rootstock onto which the variety has been grafted. Always cut off any sucker growth from below the graft. This is only ever a problem on very young plants, and Japanese maples rarely suffer from this.

Often variegated varieties and varieties of Japanese Maples with extreme leaf shapes only produce their true form on second year or older wood. Young plants of these types will often have two different leaf forms, one juvenile, one adult. Other varieties of Japanese maple may take a year or two before they show off their full adult foliage. Reversion is rarely a problem.

What sort of soils do maples grow in?

Good news! Japanese Maples are not fussy about soil types. Key to success is good drainage - Acers hate standing in water for any extended period, and not potting into too large a plant pot - Acers don't thrive in pots which dwarf the plants.

It is a common myth that Acers need ericaceous soil - our plants are not grown in ericaceous compost.