Looks like a problem with pests to me, like spider mites or scale?
Nicole

Have you looked inside the curled-up leaves? Is there webbing or anything else inside?

I've just (hopefully, finally, maybe?) kicked a year+ scale infestation on my benji & never saw any leaves curled up like that.... curling sideways, into a flat C shape every once-in-a-while yes, but never folded over like that.

GB

Pluta..how old is your Ficus?
There's a F. benji, 'weeping willow' that has curly leaves..they older it gets, the culier the foliage.

If you're sure it's a F. benji, (not curly) then check for insects.
Bugs can deform leaves.
Inspect for fine-weaved spider webbs, (Spider Mites---brown hard-shelled lumps---(Scale,) and white, cotty patches---(Mealy.) Toni

It looks nutritional to me - like a Ca deficiency. Tell me about how you're fertilizing? How long since last repot? What are you using for soil?

Al

Thanks a bunch for the replies.

It's been in my care for 9 years, and when I inherited it, it was already quite large (5 ft. or so). So don't know exactly how old. At least 9.

It's never been repotted (since I've had it, at least). It's still in a nursery grow-pot.

I fertilize from April through August using a balanced Schultz 20-20-20 liquid fertlizer once a month. So I've fertilized twice so far this spring.

No pests inside of the leaves, or anywhere else for that matter.

Two years ago I pruned some roots that were poking out of the drainage holes.

I forgot to mention, it's about ten feet away from another Ficus of the exact same variety, and that one isn't experiencing this.

Thanks again....

Pluta..Maybe you should unpot, check roots, 'remove dying/dead if any' then repot in fresh soil.
If your Ficus is rootbound, up'ing the pot, 1-2 sizes larger 'might' solve this problem.

When you water, does soil drain fast? If a plant is totally rootbound, 'to the point soil dries a day after watering,' leaves can curl. Test soil a couple days after giving a drink. Insert your finger or a stake deep into soil. If soil is dry, your Ficus needs a larger container.

Even if it doesn't need a larger pot, you should freshen soil since it's been in the same container 9+ years.

You said your Ficus was 10' from a second Ficus. Is Ficus 1, 'curly leaves,' getting more sun than Ficus 2?

Other than being rootbound, leaves curl from insect infestation. You said you inspected but didn't see pests. Hopefully, you checked thoroughly.

I hope you can resolve this problem. A 9-Yr old plant has a lot of sentimental value. Toni

P77 - I've tended to hundreds of root-bound benjaminas and never seen (or read about) any leaf curl associated with the plant being pot-bound or dry. Ficus sheds interior and lower foliage and exhibits growth primarily at branch ends when roots are tight. Leaves turn yellow and abscise when the plant gets too dry. Branch extension also grinds to a near halt under root-bound conditions. Leaf curl generally means it's being exposed to extremely bright light (too bright) or nutritional deficiencies. Since your fertilizer contains zinc and manganese, the other two possibilities are molybdenum or Calcium. If it was molybdenum, foliage would be discolored - yellow or purplish.

If you read the analysis of your fertilizer, you'll see that it contains no Ca, and probably contains very little or no Mg, so the only Ca it would be getting is what is in your tap water or what is residual in your soil (probably depleted). Since you never repotted, and I'm assuming you haven't potted up, I think that reinforces the likelihood of it being a Ca deficiency, which also fits the appearance of the leaves and the symptoms.

What the plant needs is a full repot with root work, and a soil that allows you to water freely. Adopting a fertilizer (like Foliage-Pro 9-3-6) that supplies all the essential nutrients in a favorable ratio and a soil that allows you to water properly each time you water will go a LONG way toward your achieving the best opportunity for the plant to grow as close as possible to it's genetic potential.

Let me know if you need more info on repotting vs potting-up, soils, or fertilizing. You might find the link below useful. Take care.

Al

Here is a link that might be useful: More about your Ficus