Japanese Maples. Beauty in Every Season

No garden is complete without at least one (or in his case 30), says Paul Gellatly

Photography and Article by Paul Gellatly, Director of Horticulture, Toronto Botanical Garden

Form, colour, texture, sophistication, elegance and grace—all words to describe the beloved Japanese maple. Perfect for a large garden, a small one, and everything in between. There are more options than space in most gardens. The collection at the Toronto Botanical Garden has 50 Japanese maples and I have 30 in my small garden at home, a few of which are found in both locations.

Whether they are dwarf, large, compact, airy, upright, cascading, thread-leaf or palmate—for a full sun, part sun or shaded location—Japanese maples are a beautiful addition to any garden.

Acer palmatum 'Ukigumo' sometimes referred to as 'Floating Cloud'

They don’t often need pruning, are slow growing and become more beautiful with age. Some are more tender than others, so it is always good to do some research before picking a maple for your garden. Recent advancements in hybridizing have led to a few cultivars hardy to Canadian Hardiness Zone 4, with discussions of even Zone 3, anywhere up to Zones 8 or 9. Their history can be traced back to Japan, with the first recorded plant dating to the 7th Century. For hundreds of years, the Japanese have refined various cultivars to form some of the more than 600 unique cultivars seen today.

In early spring, the emerging leaves in various colours, with flowers that hang just below the new foliage, usher in the new season with flair. As the leaves mature they take on their full glory and individuality shines through. With the shortening of the days, perhaps their seasonal swansong, their hues intensify, give one final show of colour and pizzazz, before the leaves fall to the ground, exposing the beautiful form of the branching throughout the cold days of winter, truly a four season gem for every garden.

Acer palmatum 'Mama fu'

Choosing Japanese Maples

The number of cultivars to choose from is almost overwhelming. The book Japanese Maples: The Complete Guide to Selection and Cultivation Fourth Edition by Peter Gregory and J. D. Vertrees, (available on various sites including Amazon and Indigo for around $60) is the most up-todate informational resource on maples. I have spent many hours with this book, dreaming and planning.

There are several factors to consider when deciding on a Japanese maple including form, colour, size, space and garden theme. The most common Japanese maple is the cultivar ‘Bloodgood’. As one of the first commercially available red leaf forms, it has become an anchor in many gardens. One can be found at the corner of the TBG Garden Shop as you enter the Westview Terrace. This large red cultivar opened our eyes to the world of Japanese maples and is still a standard sold in many garden centres. My all-time favourite medium sized Japanese maple, which I’ve used in several designs, is Acer palmatum ‘Koto no ito’. In Japanese this means ‘Harp String’, referring to its fine string-like foliage, which seems to dance in the wind almost like fringe. Emerging foliage is lime green, which remains as a muted green for the remainder of the season and in the fall changes to beautiful shades of orange and red. Slow growing, beautiful form and fantastic foliage make it a true winner.

Another winner, with large green leaves, spectacular form and colour is Acer shirasawanum ‘Aureum.’ It’s also known as Golden Full Moon, due to its emergent spring foliage being green/yellow, reminiscent of a full moon. Although not a great specimen for a full sun location, this slow growing maple’s bright colour is sure to lighten up any partshade garden. One can be found overlooking the Westview Terrace at the Toronto Botanical Garden. Aureum is a great specimen for a small garden and can also be grown in a planter (with proper winter protection).

One of my all-time favourite dwarf Japanese maples is called Acer japonicum ‘Fairy Lights’. This low, horizontally branched, slow growing dwarf tree is known for its extremely dissected leaves, incredible fall colour and compact nature. Its emergent foliage is green but in the fall it puts on an incredible display of bright scarlet, orange and yellow; truly a fall wonder in the garden. Although it’s not found at the TBG (yet) it has been a beloved maple in my garden for years.

Acer campestre 'Carnival'

Care & Maintenance

Japanese maples rarely need pruning and are considered low maintenance. In the spring, before they leaf out, I do a bit of selective pruning to remove crossing branches and look at overall shape. This is the best time to see the branch structure and form, without the leaves present.

In late June I do some selective tip pruning to keep the maple to scale for the space. This isn’t a requirement for most gardens, but in my small garden scale is crucially important. At this time, I also prune out any dead branches, or tips that didn’t leaf out properly. This is cosmetic and helps to keep the tree looking its best.

There are very few issues that affect Japanese maples. If you find leaves wilting and turning yellow or brown, you could have Verticillium wilt, caused by a fungus in the soil, which spreads from the roots through the sap to the upper branches where it can cause large limbs to die. Once you see the results of Verticillium wilt there is usually little that can be done and most trees will die within a year or two. Unfortunately, I have had this affect a few trees in my collection. Because it is soil borne, it is best not to plant another maple in that exact location at least for a few years.

For the first time this year, one of my trees developed aphids, which like fast growing plants. With this in mind, feeding is best done with a slow release fertilizer. Aphids are fairly easy to treat, using a weekly spray of dishwashing soap and horticultural oil, spraying them off with water, or introducing a natural predator (ladybugs) to your tree. I make every attempt not to use any chemicals in my garden and opt for natural solutions whenever possible.

There are literally hundreds of Japanese maples, each with their own unique characteristics, colour, shape, form and use in the garden. Visiting the TBG throughout the seasons will allow you the opportunity to see a few different Japanese maples in our collection, as they transition through the seasons.

As far as I’m concerned, no garden is complete without at least one—or in my case 30—Japanese maples!