Hi everyone. Just noticed on Saturday my two small Wickson on interstem trees in their second leaf started looking terrible sometime in the last week, and I’m very concerned!
On the first one (with angled rungs), the leaves all just kind of flooped down and are looking yellowish. We’ve had plenty of rain this summer, but I gave it a watering on Saturday night just in case. Didn’t seem to help. We have not had a ridiculous amount of rain and I haven’t watered more than one or two times, so overwatering seems unlikely. The drainage is pretty good in the raised terrace too, probably.
On the second specimen, the leaves are still perky, but have gone very yellow in a short period of time, even more so along the veins of the leaves.
These trees were doing good this year otherwise and put on something like 50cm of new growth. They have CAR spots, but not all that bad and less so than last year.
The last thing I did to these trees was paint the bottom ~20cm of their trunks with raw neem oil as a prophylactic against borers. That was a month ago, and they have seemed fine up until this week. Also, there are 6 other varieties in the same area and they all look ok. Just the two Wickson showing problems. Maybe they are two different issues on the two different trees.
I think of yellow leaves as an indicator of nitrogen deficiency, but that seems unlikely to me. These trees were planted almost two years ago into fill capped with imported top soil. I got that new topsoil tested (results attached) and it looked fine. Nutrients (other than N, which is not tested) close to good range, 5% OM, 6.7 pH. Last fall the whole bed got frosted with 3cm of compost, and earlier this season I was spraying the trees with dilute liquid fish, kelp extract, EM-1, and a bit of neem oil. I could put some N down in the form of pee, blood meal, or compost, but I worry about putting quick nitrogen down this late in the season.
I would be grateful to hear your thoughts on what the cause might be and any remedies that might be called for. Or maybe this is not a big deal and I should chill out…
Thanks,
-Holly