It was in 90-100F temps with a small pot and you only watered every 18 days? The potting mix in the photo looks very dry. I'd guess that it's completely stressed from heat and lack of water. I'd water it well and give it a more stable environment. Since you're into the growing season, I'd also start giving it light fertilizer.

I would also place it into a wider container and I water mine every 2-3 days in those temps.

Everything I had to say has been covered. If the twigs are green they are alive and will grow new leaves.

Hello all,

Thank you you for the replies.

It became sick in the greenhouse and I tried taking it outside to fix it. I am in southern N.Y. and it is actually still not warm outside (58f highs and 39f lows). The high temperatures I mentioned are because my greenhouse has been getting very hot even with its shade cloth and roof vents. This happened very abruptly I did not adjust my watering appropriately it seems.

Should I leave it in the greenhouse still which is still crazily swinging between 70f-100f or just bring it outside to give it a more stable albeit colder environment. Or, should I bring it out in the daytime and out it back inside at night.

Why is a tree that tall still crammed into such a small container? It should have been transplanted long ago. The root system has to be strongly root bound.

It needs a good repotting... try to soak it and remove much of the old soil as possible. And don’t be shy, a lot of small roots will fall off. Don’t worry.

the roots are guaranteed strangled by themselves!

i just did this with a neglected Meyer. The nursery let it go rootbound in a small pot.

I agree with the fact that it needs a bigger pot, however, would it still be advisable to repot it while it’s already stressed? I had always heard that repotting a plant under stress should be avoided.

anything will be better than what you’re currently doing....

yes dont wait any longer to repot it.... you’re thinking way too much...

I will try to get a much larger pot ASAP. What size would likely be best? 15 gallons? 20? 30? Something closer in size to the trash can next to it?

Check out your nearest HD or Lowes. They have 1/2 wine barrels synthetic materials usually under $20. I've bought them at Costco in the past for $14. You can always spurge and get wood for $39 at HD. I use both or your local nursery might carry these below that I've used for avocado and mandarin trees.

https://www.vikingfence.com/tree-boxes-planters/

Thank you all so much. I will pick up one of those larger barrels like pots ASAP along with several bags of citrus/cactus mix. It seems like the pots are about 24 inches diameter and ~25 gallons on average if I'm looking at the right thing online at Home Depot so I guess I will get one around that size. I guess I’ll have to unfortunately bring the tree back into the greenhouse though as it’s getting colder again (30f at night).

I will have to remind myself in the future not to treat citruses like orchids, which love to be very pot bound and don’t like a lot of water.

Yes awesome, don’t be shy when removing the old soil compacted around the roots.

UPDATE:

Hello all,

i have repotted the tree into a 20 gallon pot and it is already beginning to start putting out a few shoots. Here is my problem though: It is getting rather cold out this week down to the low 40s at night.. Is that too cold for the new shoots? Should I bring it inside? It seems happier outside so far but 42F seems a bit cold for a stressed plant but I’ve heard tangelos are hardy down to the 20s. Advice please.

Thank you so much.

40s isnt bad. Here in CA our winter nights regularly dip into the 40s and then warming up in the day. My potted citrus do just fine.

Update:

In case anyone was curious, the tangelo has regrown around 60-70% of the lost leaves. It is certainly on the mend. The tree even flowered profusely and is beginning to produce fruit.

Sounds like a good recovery. We all would love to see it.