Japanese Larch - needles turning brown

Some of the needles on my Japanese Larch are turning brown and dying! I`m hoping someone can offer a likely explanation. Some background info on my tree:

- Growing in zone 6 but my patio gets very hot (+40C) during the mid-day sun
- fertilizing approx every 3 weeks with all-purpose 20-20-20 synthetic fertilizer (using manufacture`s recommended dosage for potter plants)

Any ideas about the die back? I`d would guess it`s probably the heat...

I would say too much watering. I'm in Montreal and have few larches and no yellowing what so ever.

OK I just saw the pictures and substrat looks ok it shouldn't hold too much water. And color of the spots /needles is brownish. Could be also some other cause than over watering.

how often do you water? hot much sun does it get?

Just a thought, Are you using Scissors to trim ,? Larch do not react well to the metal ,while pinch back is i find the best method.More detail drop me a line and will give more thoughts Roger

careful with the heat & sun... after losing a beloved larch last year, i now keep my larches under a 50% shade cloth and they seem to love it... i also keep their pots in a tray of water on the hottest days

Very similar to tip blight.

I'm a rookie to bonsai but I'm pretty sure it's not too much water. My balcony has a bit of a micro-climate and it regularly several degrees above ambient temperature. I'm watering daily or every other day. Soil is quite well draining and I'm only watering once the soil appears mostly dry. Most of my growing area receives around 8 hours of direct sunlight... that's probably too much, right? I can try moving it to a location with a little shorter full-sun time.

I've yet to trim anything on this plant as I only just purchased it as pre-bonsai this year - but I'll be sure to pinch prune rather than scissors. Can I use scissors when I'm removing full branches?

Thanks everyone for your input!

Try to shade them for less hours on direct sunlight. When I saw the pictures I knew is not too much water caused by compacted / organic soil.

tripleovertime wrote:Can I use scissors when I'm removing full branches?

actual branch cutters (i.e. concave cutters, etc) would work better than scissors, but in essence, yes.

i personally suggest leaving a stub that can be worked into a natural looking occurrence of nature...
which also prevents die back going into the trunk or supporting branch...

Dmitry wrote:Very similar to tip blight.

That was my first thought.

beer city snake wrote:careful with the heat & sun... after losing a beloved larch last year, i now keep my larches under a 50% shade cloth and they seem to love it... i also keep their pots in a tray of water on the hottest days

Hello snake,

What's 50% shade cloth? So your Jap larches now do not get any direct sun at all now?

And for a stressed Japanese larch, burnt out from hot sun and hot surroundings, would you recommend giving it a shade break? Meaning less hours of direct sun and watering less and more misting on branches and foliage?

Thanks again!

All of my Larch are in full sun always. This year there has been some yellowing of needles on some, not all. I have been told that changes in temperature can cause this, we had a colder period some weeks back. Unless the watering is excessive I doubt it is too much especially in summer. Mine need watering every day regardless of rain which we have not had a lot of recently. Mine having lost some needls seem to be greening up again and are still growing.

Larch like a lot of water as long as the soil drains. It is not necessary to wait till they are mostly dry to water, that could be too dry. Just my opinion.

tripleovertime wrote:
(...) I`d guess it`s probably the heat... (...)

So would I.

When the atmopshere is very hot and dry, that can happen, even if the soil is wet with most larch species.

Here in Europe, it grows at an alitude of 1,800 to 2,900 metres, so it's a mountain tree that wants a cool night and a warm day in its natural habitat. These conditions allow the tree to benefit from the dew in the morning.

Maybe some larch species can grow in continental climates, in plains, where the weather can be very hot and dry (?), but not the Japanese Larch.

So yes, give it a "shade break": first Larix kaempferi is not a tamarack, secondly a potted tree does obviously not react the same to weather changes as a tree grown in a mountain forest.

Just plain (I mean, mountain) common sense.

tripleovertime wrote:Some of the needles on my Japanese Larch are turning brown and dying! I`m hoping someone can offer a likely explanation. Some background info on my tree:

- Growing in zone 6 but my patio gets very hot (+40C) during the mid-day sun
- fertilizing approx every 3 weeks with all-purpose 20-20-20 synthetic fertilizer (using manufacture`s recommended dosage for potter plants)

Any ideas about the die back? I`d would guess it`s probably the heat...

I have a different theory than most people here. I've never seen sun or water damage a larch, unless there are other mitigating factors. Larches are full sun trees, and are very tolerant of wet soil.

I am in the Toronto area as well and have many larches. This looks like Japanese Beetle damage.

Took me awhile to figure this out on my trees because (a) I assumed J. beetles don't eat conifers, and (b) the damage on larches looks very different than J. beetle damage on broadleaf deciduous. But since last year I have seen them actively attacking my larches. They don't seem to eat the entire needle which is strange, it more seems like the sever the needle and drink the sap. And they mostly eat the new growth at the tips.

I may be wrong, but we are in J. beetle season and that is exactly what the damage looks like on larches. Look closely over your plants... just one beetle could do the damage you see. The good news is that the J. beetle damage is easily controlled and rarely severely damaging. I use imidacloprid systemic granules (Bayer Tree and Shrub) which I pick up in the USA. Otherwise just pick them off by hand and kill them.

LSbonsai I think you're right. Couple days ago I found three of this creatures sucking on one of my Jpn. larch because of observing something like yellowing and drying needles I think you hit the "jackpot"