Tree identification and problem diagnosis

Question

Last summer I moved into a new house and it has this tree in the back garden. Can someone please help me to identify the species and also to work out why it is not growing very well.

Some branches are out in full leaf with the seeds hanging beneath, whilst other branches (probably just over 50% of the canopy) show reduced growth and poor-quality leaves.

Photos:

Updated photos 15.05.2019

The photo below shows a damaged leaf which may have originally misled, apologies for that.

Additional 2020 video footage from a drone: https://youtu.be/S-vcsmApJ7g

UPDATE 20.07.2021: The tree was pollarded in Spring 2021 and is now shooting as below. Which branches should I focus on keeping and which should be pruned off to preserve the best properties of the tree?

Answer 1

Looks to me like a Manitoba Maple (Acer negundo), although what this Canadian species is doing in the UK I don't know. This tree has compound leaves with three to seven leaflets in the more mature parts of the tree. One of the photos shows typical bright green sucker growth characteristic of this weedy species. It is a fast growing nuisance of a garden component that fills a space but produces poor wood and is rarely attractive. Its energetic, weak growth leads to loss of limbs which it cheerfully makes up for with more growth which you might not need. If I am right then the garden might be better off without it.

Update: new photos seem to confirm it is the junk tree I originally thought. Its only advantage is that it grows fast and fills a spot where you need something quickly. As soon as possible it should be replaced with something more interesting and manageable. It might take several attempts to get it out completely, so soonest mended soonest forgotten.

Answer 2

Depending which part of the UK you're in, it might just be that the top part of the tree has not fully opened out into leaf yet because of the weather conditions this year, that is, the very warm February and the recent cold spell. Even here in the south of the UK, some Acers have been slow to leaf out, especially at the top, and in some cases, the new, upper leaves have been burned back by frost.

This is an Acer of some variety, but, in the images which show the top part of the tree, it's hard to be sure that some of the leaves don't have a white or cream variegation round the edges. This might be just an effect of the light, but it would help to make an ID of the variety of Acer if you could confirm or deny whether this is the case. There is certainly no evidence of variegation on the lower leaves visible in the penultimate photo. The other question I'd ask is whether the leaves on this tree turned red before falling or not last autumn.

UPDATE

On looking again at the images, the final picture shows some growth near the base on the left hand side that looks to be variegated, with white and maybe a touch of pink. Can you confirm that is the case? If you inspect the foliage, you may notice some all green branches as well as variegated ones, if what I'm seeing is variegated foliage in some parts at all.

Answer 3

I think your acer is an Acer nigrum, that has fairly dull yellow brownish autumn color that you most likely even did not notice (any acer can't be just the same green all the way to the time of leaves dropping):

Compare the drawing above (public domain, 1913) with details of your acer.

As for remeding the problems, I would suggest removing the weekest branches (up to 20% of the tree), and thinning crowded crown areas, cleaning the area of weeds, even any grass, and watering generously this season. Small shoots from the last photo should be all removed, as they are consuming energy that should be better spent elsewhere. Then evaluate the result the next year, etc.

Answer 4

I think the tree is Acer negundo 'Flamingo', a variegated box elder. It is currently available in the UK and I can confirm that it was common in the UK as early as the 1990s (reference is "Manual of Woody Landscape Plants" by Michael Dirr, 5th ed., publ. 1997). It could also be the first two-colored form 'Variegatum', although the pink new growth seems to indicate Flamingo.

Variegated maples are difficult to grow because they tend to shoot out non-variegated twigs which, because they're 100% green in a tree that isn't, out-compete their variegated brethren. Over time, the green branches out-compete the non-green branches, causing them to die. Variegated box elders are known to do this (same reference as above). See here for an example of a Norway maple where this is happening.

Another key to the ID is if you've experienced the joys of box elder bugs in the late summer and autumn. If you have, then the ID as an Acer negundo is correct.

The drone footage shows quite a bit of loss, which may or may not be caused by the green leaves out-competing the variegated leaves. It could also be caused by environmental conditions or disease. Box elders are short-lived trees in the best of environments. Because the variegation seems to be spotty at best, it's adding no real aesthetic interest to your garden, and because it's a magnet for annoying insects, I'd remove this tree.

Answer 5

As a part of the answer looking at how the tree is mulched with barrier fabric that could be possibly an indication of why the tree is struggling. There is a good chance that the previous owners did landscaping to make the place look tidier before selling it. So if that is the case and they put that barrier fabric and mulch down before selling it may have negatively affected the tree.

As even more possible troubles for that tree would be the nearby deck. If that too was done recently. Covering the roots of a tree that have acclimated to one set of circumstances can be more than the tree can survive.

I do not know if it will recover.