Acer japonica/palmatum

[WimB]

I have a problem with the cultivation of Japanese maples. I've tried several cultivars in several places in the garden and they always die after the first winter.

Can anyone give me some clear-cut instructions on growing these beautiful trees?

Thanks

Wim

[Giles]

   (well,actually, it's at Wisley !  )

[Onion]

Dear Wim,

your problem is not special for the continent. A lot of cultivars and species of the A. japonicum and A. palmatum complex are sick. Because of the trade with this plants in western Europe the sickness distribute to Europe.
Places where you cultivate A.japonicum/palmatum are not a suitable for the next year. Most of the plants contaminate with phytophtera fungus. This is a fungus from the ground/soil.
The only solution is to dive the whole plant in a fungus bath. And you have not a guarantee that the plant will survive. Best you cultivate this plants in pots. A very carefully with fertilizer, especially when you have a fertilizer with high nitrogen parts.

[Paddy Tobin]

Wim,

You might consider the position in which you planted your acers. They are very prone to wind damage and die-back over winter is common place. It seems to be very important to plant them in shelter.

Perhaps, plants bought in the trade do carry some disease; I don't know and couldn't comment but can say that Acer palmatum grown from seed is far healthier than any bought plants, settle far quicker in the garden and grow away far quicker and healthier than purchased plants.

Paddy

[ian mcenery]

I have a problem with the cultivation of Japanese maples. I've tried several cultivars in several places in the garden and they always die after the first winter.

Can anyone give me some clear-cut instructions on growing these beautiful trees?

Thanks

Wim

Wim I grow several of these and they have never been damaged by winter conditions. In my experience they do not like being in the wind or being too wet or too dry. Oh and in summer they prefer some shade during the day

[WimB]

Thanks,

I have a very open garden so I think I've always placed them in a spot that is too windy. So I'll try it in a very sheltered spot and I'll try to find some seeds.

Wim

[Luc Gilgemyn]

Hi Wim !
I tried some in the garden too over the years but kept loosing them :
in a severe winter - in a superhot summer - etc...

So I gave up and cultivate them in pots now -  they are outside all year, except when there's permanent frost around, I then put them inside for as long as it takes - during Summer I look for a shady spot for them.  They do very well now ! 

[David Nicholson]

I have a couple in pots and have had them for nearly ten years. They do quite well as long as they get a lot of water in the Summer but they hate windy places and mine do tend to suffer from wind burn.

[WimB]

Yeah, the only one I have been able to keep for some years now is a bonsai, so it's in a pot too. But still, I would like to keep it in the open garden....

[maggiepie]

Yeah, the only one I have been able to keep for some years now is a bonsai, so it's in a pot too. But still, I would like to keep it in the open garden....

Wim, I was lucky enough to get a nice A.Bloodgood for half price last summer and decided to plant it out in the garden.
It seems to have come through winter, hope Murphy doesn't hear me.
I have it planted in front of/between 2 Blue Spruce trees, it gets morning sun and some dappled sun late in the afternoon.
I realize it is not a fancy JM but it looks gorgeous when the sun is shining through the leaves, and is hardy to zone 4 here ( up to -34C).
Also have a weeping JM in a pot that I just left in my unheated garage over winter, 'Inabe Shidare', I had it up off the floor but apart from that I didn't do anything apart from dumping a few handfuls of snow on it occasionally.
It also looks fine.
Of course, one swallow does not make a summer 

[ChrisB]

Mine all survive well here.  I have A. Bloodgood, A. dissectum (?); A. Sangukaku; A. palmatum and one unnamed one.  All seem to thrive on my very free draining soil, which is sandy and slightly acid.  Some get lots of moisture, but others not, yet they all do well.  I wonder if it is the soil conditions that help them.  They certainly don't get loads of water hanging around here, even in the foulest of weather.  Bloodgood is now about 15ft tall and looks super.  All of them grew much better once I got them into the ground than they ever did when I kept them in pots.

[Paul T]

Ah, the difference climate makes.  I have a friend who grows more than 150 of them at her place, from full sun to heavy shade depending on the variety (usually the finer the leaves the more sun and wind intolerant they are).  That said, there are some that don't mind a heap of sun.  I grow a coral bark maple (technically 'Sangokaku' I think..... has intense coral coloured bark during dormancy, upright growth habit) out in the front year between our driveways in the full sun, wind, etc.  It get watered maybe once or twice a week by a pipe I have put in so that the water is delivered below ground instead of on the surface (this means the roots head downwards not upwards to the water).  It has now survived 3 or 4 summers without a problem.  I would highly recommend it to anyone wanting to grow one in the full sun, because if it survives where we have it then it will survive a HEAP of heat.  There are a number of others that will stand full sun here as well, so they would unlikely have any problems for many of you in the northern hemisphere.  I know one I was recommended was 'Inabe Shidare' (which has dark, almost black leaves in full sun).  I have mine in a shady area and it still retains most of the colour even though it prefers full sun for the true depth of colour).  It is also the quickest and strongest growing weeping maple that I know of.  I can probably dig up a few more names that grow here in full sun, if that is of interest to anyone?  My friend with the 50 of them has to pull out seedlings all the time because she gets so many of them.... we occasionally go up and scavenge interesting ones, marking them in autumn and lifting them in winter. 

[johnw]

Wim - Some A. palmatum varieties will live and thrive here on the coast where it is much colder than Belgium.   

What we do know is that Inabe-Shidare, recommended by Paul, is a good-doer and many of the green ones are fine. Bloodgood grows in some gardens and fails in others. Atropurpureum is seed grown in North America and they are hit and miss, having said that there are a number of large old atro. trees in the city here.  They don't like wind and especially hot dry winds; I have seen them burnt in the summer warm Annapolis Valley when weeks of fogs or rain lift and there is suddenly a windy day with very low humidity.

The sensational Sangu Kaku (Sengkaki) can die the first winter or grow like mad but we can be certain that at some point it will suddenly die back and expire. I believe it has been superseded by a better cultivar.

A real surprise is Ukigumo (Floating Cloud) which seems to be one of the toughest and has done well for a number of year's in a friend's garden nearby. (And I told her it would never survive!)

We have noticed that young plants that go through a summer drought will suddenly lose dormancy with the first autumn rains and then be winter-killed (barksplit). So it is important to keep them watered in the summer and slack off the watering in October.

From time to time we see palmatums growing in very cold places like Prince Edward Island. There they do get a bit of die-back in extreme winters.

I think it is true some plants in the trade have a disease problem which may lead to failure though in this climate it is hard to say what the final cause of death was - disease or cold.

It would be a very expensive proposition to try all of them to see which are the performers!

Acer shirasawanum seems much easier to grow and trouble-free.

Acer palmatum 'Ukigumo' attached.

johnw