Why are these tree leaves browning off?

[d23]

Hi - just wondering if I could get some help on what maybe missing for these trees - per the photos, I'm starting to see leaves turning brown and dying off on both in similar locations at the front.

The area gets the morning and afternoon sun till about 2-3pm, I'm in Adelaide - it has been hot over last 10 days - lack of water or nutrients? I did give both seaweed about a week ago.

One is a Syzygium - Big Red and the trees are Ginkgo Lemon Lime Spires

Thanks in advance

  . . 

[MitchellMc]

Hi @d23,

How often and for how long have you been watering the trees over the last ten days? Is it moist or dry if you stick your finger into the soil? Once the soil dries out to finger depth, you need to water, especially in hotter weather. 

I can't see nutrients being an issue, and it's more likely due to heat stress. For those not in Adelaide, what temperatures have you been seeing?

Let me mention a couple of our horticultural experts, @Noelle and @Adam_W, to see if they have any thoughts.

Mitchell

[Noelle]

Hi @d23 

Sunburn possibly due to extremely hot sun and reflected heat and water stress - lack of water, that is.  Trees in pots in particular may need watering at least once a day over hot weather. There is not a lot of potting mix in the pot containing the syzygium and it will dry out very quickly.  While the ginkgos are in the ground, again the soil will dry out rapidly during hot spells - they are young trees with still quite small root systems so they will need very regular watering.

Aim to keep the potting mix and soil moist (not soggy wet) by watering frequently. Seaweed solution will assist in strengthening cell walls in roots and leaves so apply every couple of weeks.  Otherwise the trees all look like they are healthy which would indicate that nutrition isn't the issue.

[d23]

Thanks Mitchell and Noelle,

I can confirm both soils were fairly dry, so over the past week I've been watering once a day atleast to keep moist. 

The gingkos look like they are having a few more leaves turn yellow and die at the moment per the latest below.

Upcoming we have temps for the next 7 days above 30 and full sun....I assume just keep the soils moist to get through the heat as best as possible still?

Thanks again

 

[MitchellMc]

That sounds like a plan, @d23. 

You could consider picking up some 50% shadecloth and covering the plants on the hottest of days.

Mitchell