Revive Seiju Elm after pest attack

[AGentleman]

Hello there,
I went away for two nights and came back to see the young Seiju elm that I planted in the ground has had most of its fresh spring leaves eaten off and others browning. I couldn’t see any insects but I suspect that it is red spider mites. I shook the branches onto some paper. I ran my finger across the debris and smeared it but the smears weren’t red. Could these be dead mites? There’s no fine webbing visible in the branches either.







Should I spray it with Neem oil? Also, would it hurt my other trees to have a preventative spray of Neem oil? I’m not sure if spraying trees too much can hurt them.



The tree was very healthy when I root-pruned and planted it in the ground just over two months ago. I had wired the branches out for fun prior to planting. About a month ago I sprayed it with Yates Rose Shield. It is now mid Spring down here. It was slow to get going and the buds had only developed into leaves. It had not started pushing like my other trees. I thought that was because it was not in as good a position lower on the ground. It could have been under attack before I left but I didn’t notice.
I have taken the wire off but will probably wire it back onto some stakes because it’s still a little bit wobbly.
I fertilise it with Dynamic lifter (organic fertiliser pellets), blood and bone. And weekly I give it some organic liquid fertiliser. I also water it a lot. I wasn’t worried because it was planted in the ground and thought it would drain well.
Is there anything else I can do to help it recover?
Thanks,
Greg

 

[Shibui]

Mites have very tiny mouths. They cannot bite chunks out of leaves like this. Mite damage is caused by them sucking sap out of the leaves. Mite damage generally occurs much slower than this and would normally show up as yellowing leaves rather than chewed leaves.

My first guess would be possums snacking on your elm. How tall and how rigid is the mesh guard around the tree? I suspect most hungry possums would just climb right over that. I'd try putting some sort of cover over the top.
Possible caterpillars but they would normally be visible on the branches.
Rats occasionally take a fancy to branches but I haven't seen them eat that many leaves before.

Plants in the ground don't usually need such regular fertiliser as nutrients do not leach away as quick as in pots. I'd back off to monthly fert.
It is definitely possible to overwater trees in the ground. How often to water will depend on the soil type. Clay soils hold lots of water and plants in clay can easily become waterlogged, especially if you've excavated a hole in clay soil and filled it with a different soil mix. Try digging down in the soil near the tree to see if it's saturated, damp or dry. Only water enough to keep the soil around the tree damp. A good weekly watering should be enough for most trees in most soils.

 

[AGentleman]

Thanks @Shibui
I took the main guard mesh off for the photo shoot. It's a lot taller but a possum could have wiggled through. I've put more mesh over the top now.



Unfortunately, the possum around here developed a taste for Seiju last spring. It clawed through a plastic bag and ate my cuttings.

However, if it's a mammal, it could be rats. The neighbour over the back fence has chooks (and an amazing tomato garden). It will be difficult keeping rats at bay!

Well, regardless of what munched the leaves, I'm definitely over watering and over fertilising. Thanks for clearing that up.
Greg

 

[AGentleman]

Thanks @Shibui I never would have thought a rat or possum would have caused this damage.

After your reply, I shored up my mesh and I now know it's a pesky rat trying to eat my apparently tasty Seiju leaves. They must be quite the delicacy because the bugger tried to get at them three times while completely ignoring the bog standard chinese elm leaves which must have practically tickled its nose whilst it was frantically digging.



I now know what I need to do.

However it is quite the set back for my poor elm for which I had such high hopes. It's missed the majority of spring. If it doesn't grow that much this year, do you think it would be wise to forgo lifting it for root pruning this coming winter to let it gain strength?

Thanks Greg

 

[Shibui]

My experience is that Chinese elms take at least a year to get really going so no problem leaving it this winter, especially after such an inauspicious start.

 

[AGentleman]

Thank you