Mature Fiddle Leaf Fig is struggling. I purchased the tree in late october and
one of the three stalks already had some yellowing in the veins. In the first month or so, two interior leaves
turned yellow/brown spots and dropped. They were
small and hidden.

I am now developing some yellow veins in all the plants
along with brown spots. The leaves are
turning yellow fastest around the brown spots.
Mostly around the middle height of the plant.

The leaves at the top are bright green and soft.
The leaves from the bottom up are dry/brittle and could crack if bent too much.

I am watering about every other week and about 2-2.5 gallons,
enough for water to start running out the bottom. I used a hygrometer to test
around the roots before watering and wait till it says it's getting dry. There is about 2-3 inches of Styrofoam packing peanuts at the bottom for drainage with a layer of Vigoro Polyethylene Weed Barrier fabric on top of them.

I repotted it in a 18x18x20 inch synthetic pot, the soil I used
is a mixture of miracle grown regular/moisture balance/cactus soil with plenty
of vermiculite. I might have added a
little miracle grow bloom feed an early watering but it wouldn't have been much
at all.

It was getting a lot of light the first couple month but I have
since been closing the blinds. The room
still gets pretty good sun in the winter.

Room temp doesn't get below 65*, humidity is pretty good and
I was misting with the dry winter air.
I completely closed the air vent near it and the door does not have a
draft.

Photos 1 & 2 are from December.
The rest of the photos are from 1/23/18

I have no experience with Fiddle Leaf. Whatever the infection is it seems to be working in the plant's vascular system. Where are the experts? @WillC ?

The veining you see is a normal pattern for a leaf that is dying. Don't read anything into it. Older leaves are naturally drier and more brittle and more inclined to die back as they age. There is no infection.

Overall your Fig looks pretty healthy. It does need maximum sunlight all day long, however, so open up those blinds.

You have potted it in a very unorthodox way, so it is hard for me to advise you on watering other than the soil should never get very dry. It is good that excess water does have a way to drain out. Don't rely on the meter because it is affected by things other than moisture content.

For future reference, it is best to leave the plant in its nursery pot and set that pot inside the decorative planter. That is better for the plant and easier for you.

Vermiculite is not a very good addition to a potting mix. Initially, it does provide some aeration, but over time the particles collapse and compact. Perlite is a much better alternative.

Fiddle Figs do fine in low humidity and are quite tolerant of indoor temps and drafts. No need to mist.

Let me know if you have further questions.

Thank you very much for your insight. to correct myself, i did use perlite.

And about your comment about leaving it in the nursery pot. I have heard this before but am not sure why its better. Wont the roots just continue to be root bound? when i took it out the root ball was hard as a rock. i put it in the larger planter with hope for it to grow TALL. i have a 20 foot ceiling for it to grow into.

Also, do you find these plants to be sensitive to over or under watering

thanks again!

I acknowledge that I am an outlier when it comes to the subject of repotting, but I think for good reasons. If the roots are truly root bound, needing water several times per week, then it is certainly appropriate to move the plant to a larger pot. However, seeing roots around the outside of the rootball is not necessarily a sign that it is rootbound.

The primary danger of up-potting prematurely is inadvertent overwatering. A larger pot means more soil that will retain water longer than before. If that is for too long, the roots may suffocate. I have personally seen hundreds of plants suffering from root rot (suffocation) because they were in large pots. After repotting, it is important to adjust your watering accordingly. Many folks don't understand that and keep water on the same schedule as before.

Finally, repotting correctly seems to be a mystery to many folks. In general, it is best to disturb the roots as little as possible and not remove much of the original soil. It is okay to add fresh potting mix to the bottom and sides of the new pot, but not to the top of the rootball. Adding "drainage material" to the bottom of the pot is an outdated and discredited practice, but many folks don't know that. Any pot that holds the rootball must have drain holes. Using a potting mix that matches the soil of the existing potting mix is important. Many packaged potting mixes are contaminated with fungus gnat larvae, so fungus gnat infestations often follow repotting. Lots of things can go wrong!

Repotting is sometimes necessary, but rarely with newly acquired plants and not as often as people realize. Plants grow best when they are moderately root bound. Bigger pots don't necessarily lead to bigger plants. It is the available light that is the prime determinant of how fast and large a plant grows, not its pot size.

All of that said, Fiddle-leafed Figs can tolerate unnecessary repotting and heavy watering better than most plants, assuming it is in a very sunny location. I think yours will be okay, but don't try to force it to grow faster than the light permits. Be patient.

Excellent info! thanks very much. I feel much better about this plants direction.