Canopy Trees

[sbpalms]

I am looking for a canopy tree for my garden. It needs to withstand frost, provide shade and protection for palms and other plants, and must be low maintenance. I have three species which I am considering:

Acacia koa

Castanospermum australe

Stenocarpus sinuatus

 

[Pip]

Castanospermum australe and Stenocarpus sinuatus are really beautiful but slow growing in Mediterranean climates. Your choice may depend on how quick you need a canopy. 

[sbpalms]

Thanks for your reply. Do you think Acacia koa is a good option?

[RedRabbit]

I like ficus but they probably don't meet your low maintainance criteria. 

[sbpalms]

I actually have a fairly small Ficus benjamina in my yard which is low maintainance. I don't want to use it, or any ficus for that matter, as, although they are beautiful trees, they are VERY aggressive here. My small specimen has cracked the pot it was in. What is your opinion on Acacia koa, or any Acacia for that matter?

Edited July 6, 2017 by sbpalms

[Bennz]

I'm using Acacia dealbata and A. silvestris as fast growing N-fixing shade/wind trees in my orchard. Both species get too big but if underplanted with slower smaller acacias (A. retinodes in my case) the tall species can be removed before they get too big, by which time the others have grown enough to be useful. Bipinnate acacias are good as they can be pruned to give great dappled shade without being too dense. A. koa, melanoxylon, mangium etc with their phyllodes can create too much shade for many trees.

The  great thing about acacias is they fix atmospheric N, and are extremely attractive to acacia psyllids. The psyllids are extremely attractive to ladybirds and other predatory insects, so these trees actually help the ecosystem in a number of extremely useful ways. Down side is they do use moisture and soil fertility so extra watering is required. 

I'm also using evergreen Alnus spp (mainly jorrullensis and cremastogyne) and ErythrinaXsykesii for the same thing. The coral tree is not as fast in my cooler climate as it is in the subtropics,  I like the lush foliage as a screen.

[Missi]

Corymbia citriodora, lemon-scented gum! Quick grower and has the added bonus of keeping mosquitoes at bay! Though, not sure if you have mosquito problems in CA... 

Editing to add: Acacia farnesiana, which is an attractive acacia native to TX. FAST grower, but spiky.

[sbpalms]

Thanks everyone for the suggestions! Does anyone know of a good canopy tree in the family Myrtaceae?

[Bennz]

I wouldn't go with any myrtaceae trees at all, they tend to be too aggressive on the surrounding soils. Most are good in dry climates, but not so good to garden under. Dryland Eucs and Corymbias are particularly bad. If you do want to go there though, I suggest Metrosideros excelsa (no bias from a NZer!).

[sbpalms]

@Bennz Thank you for your comment.  Do you happen to have any other suggestions? I like both trees you mentioned, but I'd like to have a great selection of trees to choose from. 

[Jeff_Cabinda]

Albizia julibrissin. May I propose it to you? Also exists with red leaves... Very Nice easy and quick to me. Withstand frost

[Bennz]

I'm biased, I'm an organic farmer with permaculture background and like to see ecosystems designed to maximise environmental benefit. So for me I look at N-fixation, nutrient recycling, degree of required shade (evergreen/deciduous and foliage density) and flowering intensity and duration. Acacia retinodes is good as it is only moderate sized and flowers almost year-around, great for insects, but the crown is a little too dense for gardening under so needs thinning (and boring to look at frankly). Bipinnate acacias and albizzias are great as they tend to let the rain through well, and often have long flowering periods, and good N-fixation. Potentially weedy, if that is a problem. A. jullibrissin is good if you want a flat-crowned deciduous tree, but other Albizzias are great too. I like A. adianthifolia from Southern Africa, but it doesn't nodulate in NZ so not so good here. Tipuana tipu might be  a good option. How about Cassia leptophylla or other Cassia spp? Maybe Sesbania punicea if you don't want too much height? There are a lot of other tropical tree legumes that you will be able to source that I don't know well and can't access in my country so I'm probably not much help.

[Jeff_Cabinda]

Cedars are to me one of the nicest trees. So many species. Well cared I am sure it would create a dreamy canopy. Care must be paid to pH... though... tiens check-list there compatibility with palms...

[Jeff_Cabinda]

To check there compatibility with palms...

[Bennz]

45 minutes ago, Jeff_Cabinda said:

Albizia julibrissin. May I propose it to you? Also exists with red leaves... Very Nice easy and quick to me. Withstand frost

Jeff, frost is surely something you would know nothing about in Cabinda?

 

 

 

 

 

45 minutes ago, Jeff_Cabinda said:

45 minutes ago, Jeff_Cabinda said:

 

[Jeff_Cabinda]

I spend 50% of my time in France.  In Grenoble in the french alps you can see there nice specimens whereas Temperature goes sometimes below -20 degrees celsius

[sbpalms]

The Albizias are nice, but I'm trying to look for a canopy tree that isn't deciduous. Do you think Acacia koa or melanoxylon could be viable if it was trimmed to allow adequate light through? I really enjoy the look of the leaves of both species.

 

[Matthew92]

1 hour ago, sbpalms said:

The Albizias are nice, but I'm trying to look for a canopy tree that isn't deciduous. Do you think Acacia koa or melanoxylon could be viable if it was trimmed to allow adequate light through? I really enjoy the look of the leaves of both species.

 

On 7/5/2017, 12:26:06, sbpalms said:

Thanks for your reply. Do you think Acacia koa is a good option?

I recently was doing research on Acacia koa, and from what I found it seemed that they were VERY cold sensitive. I find this hard to believe though because they grow on some of the mountain sides in the Hawaiian islands. Very nice tree though. I would want one in my yard. 

[Bennz]

3 hours ago, sbpalms said:

The Albizias are nice, but I'm trying to look for a canopy tree that isn't deciduous. Do you think Acacia koa or melanoxylon could be viable if it was trimmed to allow adequate light through? I really enjoy the look of the leaves of both species.

 

I've got A. melanoxylon in my orchard. It does get very dense, too dense for fruit, but palms grow fine under it. There are different forms of this tree, the big ones can get close to 40m tall and over 1.5m trunk diameter (130 x 5') so not something you would want to leave too long. Grow several close together and cut one out every couple years for coppice mulch and the problem is solved. A.melanoxylon and koa look very similar, koa being more spreading unless tightly spaced. A. binervata is also a nice tree with more attractive phyllodes (my opinion), being larger and lusher, more like A. mangium. Another bipinnate option is A. elata, one of my favourites, very large leaves.

 

What are you actually intending to grow under the canopy? 

[sbpalms]

4 hours ago, Opal92 said:

I recently was doing research on Acacia koa, and from what I found it seemed that they were VERY cold sensitive. I find this hard to believe though because they grow on some of the mountain sides in the Hawaiian islands. Very nice tree though. I would want one in my yard. 

I too thought the same at first. After a bit of research, it seems to be a relatively hardy species of Acacia. I've actually heard reports of it growing in Northern California, although it is very tender while young. I would assume a mature specimen would be hardy to approximately 20 degrees or so, which would make it great for protecting cold sensitive plants in my area.

 

1 hour ago, Bennz said:

I've got A. melanoxylon in my orchard. It does get very dense, too dense for fruit, but palms grow fine under it. There are different forms of this tree, the big ones can get close to 40m tall and over 1.5m trunk diameter (130 x 5') so not something you would want to leave too long. Grow several close together and cut one out every couple years for coppice mulch and the problem is solved. A.melanoxylon and koa look very similar, koa being more spreading unless tightly spaced. A. binervata is also a nice tree with more attractive phyllodes (my opinion), being larger and lusher, more like A. mangium. Another bipinnate option is A. elata, one of my favourites, very large leaves.

 

What are you actually intending to grow under the canopy? 

Thanks for the suggestions! I'm just starting my palm garden, I'll likely use the tree for tender palms in my area (maybe a Clinostigma or small Dypsis) and as a source of shade and wind protection. I really like the look of Acacia binervata and mangium, the phyllodes are indeed large! I like the appearance of Acacia elata, as well. What is your opinion on Hymenosporum flavum as a canopy tree?

Edited July 8, 2017 by sbpalms

[Bennz]

45 minutes ago, sbpalms said:

What is your opinion on Hymenosporum flavum as a canopy tree?

Nice tree, good flowers/scent, Aussie rainforest tree does best with some moisture. In my climate it is a little slow, slower than I would want for a shade/shelter tree. Acacia dealbata and A. silvestris can get to 12' in a year if they are happy, Hymenosporum would take at least 3-4 years to reach that size in my climate. 

[Pip]

Hymenosporum flavum is a great tree here in Adelaide, does well in moisture retentive clay based soils. It can be darwfed by the summer dry climate but with a little irrigation and mulch this species is much quicker.

[sbpalms]

Thank you both for the information. Hymenosporum flavum is very common in Santa Barbara, and seems to grow well even with our rainless summers. @Bennz I know you advised against using members of Myrtaceae as canopy trees, but what is your opinion on Lophostemon confertus?

[Bennz]

5 hours ago, sbpalms said:

 @Bennz I know you advised against using members of Myrtaceae as canopy trees, but what is your opinion on Lophostemon confertus?

Up to you bro (bro-ess?), all I'm saying is I personally would prioritise N-fixation and nutrient recycling (for the soil), then flowering (for insects), then water/nutrient useage, then aesthetics, but everyone has their own set of priorities. With all due respect, I think Jeffs suggestion above about planting cedars is about the worst thing you could possibly do to garden under, I suggest Cedars need to be well out of the way and appreciated from a distance. Growing Eucalyptus, Corymbia, Syncarpia, Lophostemon etc is not as bad, and in a high rainfall area they are actually rainforest trees with a full understorey, but they will still present difficulties as they are adapted to take full advantage of all available soil moisture and fertility.  Also do you have myrtle rust in CA yet? If not, it will be there soon no doubt.

30 years ago I planted a Eucalyptus shelterbelt around my orchard. I suggest anyone else who tries myrtles will eventually regret it as much as I did. But if you really like them then do it.

[sbpalms]

@Bennz I'm considering some NZ native plants. How do you feel about Pouteria costata, Vitex lucens, or Dysoxylum spectabile?

[Bennz]

Puriri and kohekohe are two of my favourite trees.  Both trees have some extremely attractive huge-leaved genotypes. I'm not as familiar with tawapou. All are comparatively slow growing, and dense foliaged, so will give dense shade. 

[sbpalms]

I really like Vitex lucens. I might choose this tree for canopy.

[Peter]

I'm a bit late to this discussion, and maybe it's moved on, but I think the best canopy tree for Southern California is Tabebuia.  Low maintenance, needs very little water, plus has the (IMHO) the best flower display of any tree we can grow here, and it lasts for 6 weeks.  And is not rooty and is handsome out of flower as well.  What more can you want?  My two cents.

[sbpalms]

I was considering Tabebuia. Aren't they deciduous in winter, though?

[Peter]

Tabs drop their leaves briefly in the winter, but then send out their flowers so the display is much better as they flower with no leaves.  Once the flowers start fading, the new leaves come in, so it really is a small window when it is bare.

 

[sbpalms]

@Peter Oh, I did not know that. I really like their flower display! Which species do you recommend?

[Peter]

Impetiginosa is the pink variety that grows and flowers the best.  Chrysotricha is the most common yellow, but they tend to be scraggly here for a long time, and can be quite slow.  There is a nice hybrid that the LA Arboretum made that is a cross between the a pink and and a type of yellow that is generally called Apricot-that one is very nice but hard to source.  Recently some nurseries in Florida have been selling various crosses with awesome flowers, similar to the Apricot Tab.