Hi everyone,

I've had a ficus elastica for a few months now and, while otherwise healthy (it has new leaves growing), there is a persistent issue with older leaves progressively turning their edges brown and dry (see pictures) and eventually falling. I have repotted the plant shortly after buying it, I keep it fairly close (1 meter away) to an east-facing window (although to be fair I live in the first floor and during winter there is not much light), I water it approximately once a week, and I add general fertiliser every month. Is there something I am doing wrong? Should I fertilise more or get a specific fertiliser?
Thank you!

Fertilizer shouldn't be the issue. I notice there is leca in the pot. Is this plant totally planted in leca or is there soil underneath?

No no there is soil underneath, I just put some leca on top following the suggestion of a friend because there were a few tiny 'flies' around the moist soil (actually they're still there, although maybe a bit less). The soil is the one the plant came in, it had and still has some moss on top, plus I added some light soil mix when I repotted it.
This is an issue I've seen quite a few times when coming across this type of plant around Geneva, but I couldn't find any related topics on this forum. Could it have to do with the tap water here??
I really don't what to do! It makes me sad to see my plant killing her lower leaves to make the new ones grow

Tiny flies means you have fungus gnats. Their presence means you have waterlogged soil. Your Ficus elastica issues are likely due to overwatering.

Is there a drainage hole in the bottom of the planter?

How often do you water?
Is the soil still moist when you do?

How much light does your plant get during winter?
If you can, move it closer to the window or right up to it.

I believe it's a light and watering issue. Indoor light (even near a window) is not as intense as it would be outdoors and potting soil takes much longer to dry out in the lower lighting situations inside our homes. I'd advise moving the plant as close to the brightest window as possible, remove the Leca from atop the soil and cut back on watering. Test for soil moisture every week or so by sticking a finger about 2 inches down into the soil and if it still feels moist, hold off a bit longer before watering. Depending on the type of media and how quickly it dries, will determine how often you should water. Fungus Gnats are a sign of overly wet soil and I'm not sure whether Leca will deter those pests or not but Leca won't cure the problem of the soil staying too wet at root level. When watering, you should pour water atop the soil until it begins exiting the drain holes of the pot and wait to water again until the top 2 or so inches of soil are dry to touch.

I can't advise on fertilizer since I don't feed my plants but fertilizing more than once a month sounds quite excessive to me and over fertilizing can cause problems of root and foliage burn.

Thank you @hlutzow and @plantladylin, this is of great help!!!

After having read your replies I made some checks, so I need to make a few clarifications: 1) the window is actually south-west facing, with the light coming more towards the afternoon; there is a radiator right next to the window, and although it's most of the time off because it's our bedroom, I put the plants a bit farther from the window so as to not be in the line of the heating; 2) the plant sits next to another plant, a lucky bamboo, which at this point I'm sure has a problem of waterlogged soil (see my other question) - the flies seem to be more in that one, and I think from there they spread to the ficus; 3) I sticked my finger in the soil of both vases, and noticed that neither is completely dry about 2 inches down (more the ficus), and that the inner part of the vase (in between the main branches) is more moist than the outer part (I think that's the soil from the nursery, while the one I added when repotting sits mostly on the outer circle, and seems more light/transpirant).
I'm adding two pictures to clarify.

To respond to your questions @hlutzow: yes there is a drainage hole; I water once every week more or less, because that's when the soil seems to become dry (but I didn't go 2 inches down, so I'll start doing that and eventually water less); the plant gets quite a indirect light throughout the day, especially in the afternoon when the sun is west, but it's still a first floor and during these winter months if it's a bad day there is really not much light (see picture: it was taken in the morning of a good day, but it's rarely like that). And @plantladylin: I don't fertilise more than once a month, actually probably more like once every 1.5-2 months, although I was trying to do once a month now because people told me the browning leaves might be for a lack of nutrients.

So to sum up:
1) I'll move both plants right in front of the window as you both suggest, at least for the rest of the winter
2) I'll remove the leca and water only when the soil feels dry about 2 inches down, so less than I'm doing now
3) when I do water, I'll do it until water comes out of the draining hole. One question here @plantladylin: shall I remove straight away the water that remains in the saucer?
4) @hlutzow: do you suggest doing the leaching of the soil for both plants next time I water (I'm referring to your reply to my other post here)? In case there is some residue of minerals or some mould in the roots?

Sorry for profiting of your patience and expertise, my plants and I are extremely thankful :)

ali87 said:@plantladylin: shall I remove straight away the water that remains in the saucer?

Yes, you should always immediately empty any excess water from the saucer/tray. When the pot sits in water, the roots will remain saturated causing oxygen depletion and rot. When watering, you can remove the plant from the tray and sit it in a sink or tub, water thoroughly and then allow the excess water to drain away before placing the pot back onto the tray.

I keep all of my indoor plants sitting on trays of leca or pebbles and I keep a little water in the trays at all times. As the water evaporates, it raises humidity around the plants but the leca/pebbles raise the bottom of the pot to prevent water from saturating the roots.

It wouldn't hurt to leech both plants next time you water.