Category Archives: My London Garden

Ten top trees for a small garden

Planting a new tree in a small garden is not a decision you take every day, every year or even every five years. Having recently decided to remove a very large and over dominant Japanese cherry tree from my garden, I now face that decision. So here are my thoughts on the subject.

Height and spread: My last cherry tree – Prunus shirotae Tai Haku – was planted in about 1995 and in almost 25 years grew to about 6-7 metres tall with a spread of at least 5 metres. I think I don’t want such a large tree again, but in another 25 years I might be past caring! The garden probably won’t be my major concern then if I’m still around.

Reasonably though, I think I can say that I would not mind another tree that grew to 8 metres in 25 years provided it’s spread was less. But if I’m going to buy it at a reasonable size – and I think I will need to in order to quickly restore my garden – then it shouldn’t grow too fast. A reasonable aim would be four metres or so in 10 years and a spread of no more than three.

Trees I’m ruling out because they are a shade too big include the handkerchief tree (Davidia involucrata), the tulip tree (Liriodendron tulipifera) and stewartia .

Do I want red leaves, green, yellow, blue or silver? I think red leaves on what is probably going to be the largest plant in the garden might be oppressive. So I’m thinking green to yellow. Silver is nice and blue is great.

Anyone choosing a tree needs to think about their site and whether it will be suitable for the chosen tree. I have a sunny site and well drained soil, so I’m lucky, but there is a slight question of exposure to north winds. Poor drainage and shade might make a choice more difficult.

Here’s the ten trees I’m looking at in detail:

1. Japanese maple eg Acer palmatum Seiryu
2. Cornus kousa var chinensis
3. Snake bark maple Acer capillipes
4. Rowan Joseph Rock
5. Amelanchier lamarckii or Amelanchier alnifolia Obelisk
6. Betula jacquemontii
7. Cercis eg Cercis chinensis Avondale
8. Magnolia
9. Styrax japonicus
10. Acacia baileyana purpurea

1. Japanese Maple

Bearing in mind my size requirements, there are many which might fit, and many which might remain too small. Those that fit my size requirements include Seriyu, Sango-kaku and Red Wood.

Seriyu

Seriyu is part of the dissectum group with very finely divided leaves. It is relatively tall – an October 2016 article in The Garden magazine says 7m tall with a spread of 4m, but there is no age specified. The plus points of this tree are its fine shape and elegant leaves which colour up in autumn.

Seriyu tree Image: Gardening Express
Autumn leaves of Seriyu . Image: Gardeners Dream

Sango-kaku

My own experience of this tree suggests it will reach about 6-7m in 20 years with a spread of perhaps 4m which can be curtailed by pruning. It has fine yellowish foliage in the autumn, its young shoots are red and the tree has an elegant profile.

Sango-kaku Image: Tim Gainey

Red Wood

This is an improved version of Sango-kaku, according the 2016 article in The Garden. It has similar foliage but perhaps redder bark and is perhaps slightly smaller. Its height is given as 6m with a spread of 4m.

Red Wood . Image: Pintrest
Red Wood stems and leaves . Image: Katsura

2. Chinese Dogwood

Cornus kousa v. chinensis Image: Trees Direct

Also known as Cornus kousa, this small tree is variously quoted at 3 to 4 metres tall at 20 years with a 3 metre spread. It has a lovely form and fine flowers in May-June in the UK. It also bears a red fruit and has good autumn colour.

The tree comes in various forms, the standard being Cornus kousa v. chinensis. The variety China Girl may be slightly different but I’m not sure how. It needs a sunny site and well drained soil.

Cornus kousa China Girl . Image: Ornamental Trees
Fruit of Cornus kousa . Image: Exotic Cactus Collection

One of the things that puts me off this tree is the fact that I know one of my friends treasures it and has it in her garden!

3. Snake Bark Maple

This is an unusual tree which one doesn’t see often. It’s chief attraction is the ornamental bark, but the leaves are also an interesting shape and turn red in the autumn.

There are several species which appear under this English name: Acer capillipes, A. davidii, A. rufinerve and A. tegmentosum for example. All have similar attractive bark but in terms of size, you need to be careful about what you are buying as they may vary.

UK retailer Ornamental Trees lists the height of Acer capillipes as 5m with a spread of 4m in 20 years, A. davidii as the same, and A. rufinerve as 7m x5m. It does not sell A. tegmentosum, but Burncoose Nurseries lists this species as 10m x 8m.

I have seen a snake bark maple growing in my locality and it was a well mannered tree, not growing too fast or out of shape. My bet would be that this was A. capillipes or A. davidii.

Acer rufinerve . image: Tree Shop
The bark of Acer capillipes . image: Travel with intent

4. Rowan Joseph Rock

Of all the many varieties of rowan trees (Sorbus) I think this is among the best. Its attractions are its leaves which colour up nicely in the autumn, its yellow berries and of course its spring blossom.

Ornamental Trees gives its height and spread as 6m x 4m in 20 years.

Sorbus Joseph Rock . Image: Langthorns Plantery
Sorbus Joseph Rock . Image: Pinterest

I will say no more as I know from experience it does not like the sandy soil and dry summer climate of my garden in Hackney. In the early 1990s I planted a 2m tree which seemed to get smaller by dying back each year. I then tried grafting stems onto other Sorbus rootstock. I produced a decent looking young tree but still it didn’t grow.

So if you are planning to plant it, then clay or higher rainfall may be what it likes. Having spent several years of failure, I don’t think I’ll try giving it space in my garden again.

Joseph Rock with autumn colour . Image: Scotplants

5. Amelanchiers

Amelanchiers are small trees or shrubs with lovely white (or pinkish) flowers in spring, bright autumn foliage and small berries which are loved by birds. They are native to North America and there are many species – for example: A. canadensis, A. lamarckii, A. x grandiflora and A. laevis, plus many named varieties.

Amelanchier lamarckii. Image: Jacksons Nurseries

English names include Snowy Mespilus, Serviceberry and Juneberry. You can buy them as shrubs or trained trees up to 2m in height. They are reported to be tough and tolerant of a wide range of conditions. Their natural habitat is as under shrubs in forests, and the Royal Horticultural Society (RHS) says they look good dotted around in a woodland garden.

Amelanchier x grandiflora Robin Hill. Image: Caragh Nurseries

I am not sure, however, that the growth habit of these trees will suit everyone. Although you can buy them as trees, they look like they are apt to become many stemmed shrubs. I can quote from the RHS website which says: “As a small specimen tree  A. lamarckii is agreeably manageable, reaching 4-5m in 10 years. However it does have a slight drawback in that it does not have a definite habit: it suckers from the base, meaning it will quickly revert to a shrubby, multi-stemmed habit if not pruned to encourage a clean trunk.”

I suspect the same is true of most Amelanchiers. I note that the website of Ornamental Trees – a comprehensive UK tree retailer – notes for all Amelanchiers that you should prune out growth more than four years old to retain shape and vigour. Of course that’s not so applicable to trees!

So I think that you will have to prune Amelanchiers regularly to maintain a clear stem if you want a tree. But if you’re looking for a big decorative shrub/small many-stemmed tree they are ideal.

Amelanchier canadensis . Image: The Times

Perhaps a slight exception may be A. x grandiflora Robin Hill which may work as a tree. Ornamental Trees describes this variety as having a more upright habit than most Amelanchiers. There are also plenty of images on the web which suggest it can be kept as a tree.

Amelanchier x grandiflora Robin Hill. Image: stpaulsgarwood.com
Amelanchier x grandiflora Robin Hill. Image: Connon Nurseries

6. Himalayan Birch

Birches are lovely trees and are extremely fashionable, which means of course that they are everywhere. They don’t seem to mind growing in London even though you might think it is getting too warm and dry for them.

I have chosen to look at the Himalayan birch, Betula jacquemontii, as it seems to be smaller that the magnificent Betula pendula – the UK native silver birch. Nevertheless, the RHS lists its maximum height as 12m and its spread as 8m but it would take over 20 years to get to this size.

The bark of the Himalayan birch is even whiter than the silver birch, but it does not have the same weeping habit. Many-stemmed forms of all birches are also popular and have the advantage of maximising the attraction of the stems.

Himalayan birch trees Images: Van Den Berk

7. Judas Tree

The Judas Tree, Cercis siliquastrum, produces a bold statement in spring with strong purple flowers before its leaves develop. I’ve seen it in mediterranean climes where the blossom can be stunning. They are widely planted as street trees in some parts of the south of France.

Cercis belongs in the pea family, Fabaceae, and it does produce pods after flowering. Other cultivated species include C. chinensis and C. canadensis.

The Royal Horticultural Society says some C. siliquastrum can get to 12m high and an 8m spread, but I have never seen one that large. So be wary what you buy. To be sure of a small tree there is C. chinensis Avondale which grows to a maximum of 4m with a spread of only 2.5m.

Other cultivars worth noting are the purple-leaved C. canadensis Forest Pansy, which only grows to about 2m high and 2m spread. Its leaves are large and beautiful and is grown more for these that the flowers, which are less conspicuous. Then there is C. canadensis Ruby Falls which has purple leaves, is described as having a weeping habit and again rarely gets taller that 2m. Its flowers are larger than those of Forest Pansy.

Cercis silquastrum blossom Image: Ornamental Trees
Leaves of Cercis chinensis Avondale Image: Van den Berk Trees
Cercis chinensis Avondale . Image vdberk.nl

And then there’s the C.canadensis alba form with the white blossoms. Apparently this can get up to 10m so a substantial tree.

Cercis canadensis alba . Image: flickr.com

My impression of Cercis from looking at images on the internet is that if you go for a multi-stemmed plant then you are going to end up with a thicket. But if you trim down to a single trunk then your will get a small tree which is a very spreading lollipop shape.

8. Styrax japonicus

Styrax japonicus or the Japanese snowbell tree is a deciduous tree with white flowers that grows to about 10m high and 4m spread in 20 years, so it is a little on the large side for my garden. However, it is unusual and elegant with the benefit of many white blossoms in May, probably lasting longer than those of a cherry tree.

Styrax japonicus Pink Chimes Image: Melissa Clark Photography

Styrax japonicus, in the Styracaceae family, comes in many varieties including Pink Chimes above with the slightly pink-tinged flowers. Generally though the flowers are pure white and hang neatly from the spreading branches. In the UK, Burncoose Nurseries has a wide range of varieties, including other species of Styrax.

Hanging white flowers of the Japanese snowbell tree Image: Melissa Clark Photography

It wants full sun and a sheltered position, so it likes a good spot. But it is very elegant and can be controlled by pruning after flowering, the Royal Horticultural Society tells us.

9. Magnolia

There are so many magnolias it is difficult to know where to start. The commonest one in the UK is M. x soulangeana, of which there are many pure white to pink varieties. All are spring flowering before the leaves develop and the typical look is large tulip-shaped flowers with broad white petals flushed with pink from the base. The trees are deciduous and like a sunny spot.

M. x soulangeana gets big when it gets older – the Royal Horticultural Society says 6-8m in height and spread at age 20-50 years. It’s true. And it will spread if you let it. But it is undoubtedly beautiful and worth considering.

Other smaller varieties include M. x loebneri Leonard Messel. I’ve never seen this more than about three metres tall and it has spidery fragrant pink flowers in the spring. The RHS gives a maximum height and spread of 4-8 metres with a similar spread.

Magnolia x loebneri Leonard Messel . Image: Gardening Express

There is also M.stellata Water Lily, but this is up to 2.5m, according to the RHS, so more of a shrub than a tree.

Magnolia stellata Water Lily

10. Acacia baileyana purpurea

This small acacia, also called the Cootamundra wattle, is notable for its lovely blue foliage which is purple when young. It produces yellow flowers in the depths of winter – January and February – and grows to a height of 4-5m in 20 years with a spread of about 3m.

Acacia baileyana purpurea foliage
Acacia baileyana purpurea in flower

I speak with some experience, having planted one in my south-west-facing front garden 25 years ago. It has been a joy and something passers-by often ask me about.

Acacia baileyana purpurea tree . Image: Dangergarden

I don’t intend to plant another just yet. So no further consideration for me but check it out if it is new to you. My tree is about 4m tall with a 2-3m spread. It attracts a lot of attention from passers by who ask me for its name!

Flowering in January

My small London back garden is north-east facing and on a sandy loam soil. It is about five metres wide, 30m long and fortunately completely walled. I guess I should also mention my front garden which is south-west facing, but that is only about three square metres and is dominated by a small tree and a wisteria climbing the front wall of the house. This is all that I have to make beautiful and what I’m trying to show here is that it is possible to have points of interest all year round.

January is a challenge. It is not the most exciting month of the year but there’s more to see than you might think…

Camellia sasanqua Yuletide on Christmas Day 2019

This is one of the sasanqua camellias that are known for flowering in the autumn and winter. This lovely crimson Yuletide came out last year on Christmas Day and then flowered throughout January. Unlike some other sasanquas, it is good at holding on to its petals.

It is currently in a pot but as it gets bigger it might be better in the ground. My experience is that although my soil is at best neutral and often contaminated with concrete or mortar, with a good mulch of leaf mould or matured woodchip, camellias of all kinds can do well.

Camellia Yuletide in January

Then there is the witch hazel, Hamamellis x intermedia ‘Arnold Promise’. Its yellow wispy petals are designed to attract insects, though I haven’t seen any visiting them.

Hamamelis x intermedia ‘Arnold Promise’

I’m pleased to have some Cyclamen coum, which flower in the spring rather than the similar Cyclamen hederifolium which is so noticeable in the autumn. In fact, I have planted this only in my front garden which is just a few square metres of south-west facing garden. Everywhere else, the cyclamen are C.hederifolium.

I’m told you can’t grow the two together as the autumn-flowering species tends to take over. My experience is quite consistent with that, and I have deliberately removed C.hederifolium from my front garden.

Cyclamen coum in the shade of my Acacia tree

Also in the front garden, towering above the cyclamen, is this acacia which is flowering beautifully this year. This tree is rather splendid and gets a lot of attention from passers-by who constantly ask me for a name. Generally though, this is in the summer when its chief attraction is the purple young growth nestling against the older blue-grey leaves.

dig

Finally in the front garden, there are some Crocus tommasinianus purpurea nestling against the base of a south facing wall. I call this my two-inch border, and I try and restrict it to a few small bulbs and succulents. Last year I cleared it out and sprayed it to kill of an infestation of a copper-leaved Oxalis which is very weedy in gardens around here.

Crocus tommasinianus purpurea

In the back garden there is a large mahonia which is in flower through the autumn and winter. It requires vicious pruning after flowering but does produce black berries much-loved by blackbirds. I am careful to allow many of these to remain available.

Mahonia aquifolium Charity

It’s hard to admit to failures, but I have not had much success with snowdrops. I have flowering a single Galanthus elwesii which I bought some years ago in a pot. It has clearly not spread wildey!

I have also transplanted a couple of clumps of smaller snowdrops, which I assume are G. plicatus, from my mother’s garden, which was on a clay soil. But they are not in flower yet.

I think that snowdrop doesn’t like my soil but it could just be that they don’t like drying out in summer, which is very likely here. They are planted in the shadier side of the garden in an area where I am doing my best to put plenty of leaf mould and mulch.

A single snowdrop: Galanthus elwesii

Finally, a nice surprise. I have been growing the pineapple-scented sage for some time but with little success. I gave it plenty of sun last summer and was disappointed that there were no flowers. Now it has burst into life! I didn’t realise that it likes to flower in autumn and winter, which is difficult because it is certainly not very hardy. I keep it close to the house to benefit from the heat, but it gets no sun at all just now.

Salvia elegans Scarlet Pineapple