It''s been really cold since January (32ªF / 0ºC at night) and my house is cold , so inside it hasn't been much warmer than outside.
The days are luckily sunny and I've put the plant outside during the day then back inside when it starts getting colder.
It's also in front of a south facing window so plenty of sunshine.

The soil was constantly moist, even though I haven't watered it in forever. The spots started on a leaf, then 2 and all of a sudden almost all leaves were damaged.
I switched the soil last week and was as careful as possible not to damage the roots but maybe I did some damage :/ The root ball was soaked. I haven't watered it since.

You have a lot going on with the plant, so it will be tough to nail anything down with what info was provided, but the info does want me to make some observations.
Chlorophyll is a pigment and is sometimes thought of as nature's sunscreen for plants. Moving your plant outdoors into full sun can cause a chemical reaction in the leaves (photo-oxidation) that actually produces hydrogen peroxide which attacks the first living cell it contacts. Since the plant parts with the lightest coloring have the least chlorophyll, leaving them largely unprotected from direct sun, they show symptoms first. We commonly call this sunburn. There is also the potential for the issue being chill injury, which can cause leakage of specific compounds from sells into the spaces between the cells. Also, low temperatures inhibit photosynthesis, which is like forcing your plant to use it's reserve energy to keep systems/ processes orderly. That's not a good thing.

"Constantly moist/ haven't watered in forever ...." sends up a big warning flag. If the top of the soil stays moist or your watering intervals are measured in weeks, root function or root health are being significantly affected. Roots need oxygen as much as they need air, so you should allow your soil to become almost but not completely dry before you water. You can use a 1/4-5/16 wooden dowel (from any hardware) to tell you precisely when it's time to water. You can use a bamboo skewer, but the dowel works better. Cut the dowel in half and sharpen the ends (4) in a pencil sharpener. Push it into the soil, all the way to the bottom. Pull it out and observe the tip. If it's wet or muddy looking, withhold water. When it's almost dry, it's time to water.

Also, this trick can remove a LOT of excess water from the pot after you water: Water thoroughly, then tip the pot at a 45* angle. Compare B to A below to get a meaningful sense of how much excess water you can eliminate from the pot.


If you are measuring your watering intervals in weeks, it's not just a heavy hand on the watering can that's causing your concern. Your grow medium is also an issue. Keep that thought in the back of your mind, because getting to a place where you don't have to battle your growing medium.soil for control over your plant's vitality is a game changer and can make a huge difference in the effort:reward ratio.

Al

The soil is dry now but I still haven't watered the plant since I didn't want to mess with the root spaghetti and some soil stuck to the root ball was still moist.
I added some rocks on the bottom of the pot to ensure the drainage doesn't get clogged, and mixed perlite in universal potting soil to make it less compact.

The damaged leaves don't feel dry to the touch, the brown parts are soft and feel moist on the edges of the leaves.

The weather is starting to improve, spring arrives early here.

I really like this plant

Where do you live? You might want to consider adding that info to your user page so it ends op showing on each of your posts.

It's essential that the entire root/soil mass is soaked regularly, then is allowed to dry down to where the soil is getting close to but is not quite dry at the bottom. Your plant can't survive without water, and will suffer from too much water, either extreme being capable of being an end-of-life experience for the plant.

For now, don't worry about the leaves. Getting the watering under control and determining what the appropriate watering interval is, should be your first priority. Once you get that dialed in Your plant should improve. If you can nurse it back to good health, I can help you be rid of all the damaged foliage and help you get it to grow new leaves and more branches.

You should think about fertilizing, too. please don't be taken in by advertisers touting a product for Ficus, especially for a particular species of Ficus. The products are snake oil. I suggest Foliage-Pro 9-3-6 as your 'go to' fertilizer for houseplants. It has ALL nutrients essential to normal growth (from a single container), in a plant-friendly ratio, and has other attributes few fertilizers can claim.

Your plant should be kept warm, 70-80*F, and out of direct sun. Just because it's sunny outdoors is not reason enough to move your plant there. It does not like temperatures below 55*F.
Al

Is in front of the window too much? I can move it back a bit so it doesn't get direct sun during the afternoon.

Regarding fertilizer, I have a universal fertilizer bottle. I usually do it once a month.

Is in front of the window too much? I can move it back a bit so it doesn't get direct sun during the afternoon. The question is, is the spot where you took images of the plant it's regular spot? If it is acclimated to that spot, direct sunlight is no problem, though if it is in direct sun, you should have a fan moving air. All my Ficus (45 at last count) are in full sun from end of may until (usually) sometime in October, so even the variegated plants can definitely tolerate a full sun photo load indoors, but the potential for heat build-up in leaves due to passive solar gain should be addressed if they are in full sun indoors where air is still. Sunburn is an issue quite different from heat damage and needs to be addressed differently, in large part through proper acclimation to full sun.

What fertilizer are you using? Brand and NPK %s will be found on the packaging. Not all fertilizers are appropriate, and surprisingly, some of the most commonly used products are least appropriate.

Al

>The question is, is the spot where you took images of the plant it's regular spot?
Yes, that's the usual spot. I tend to move it a bit further back during the summer months as it can get quite hot.

>What fertilizer are you using?
Had to check the ingredients list. It's 7%N/5%P/6%K with macronutrients

For Ficus, a fertilizer with a 3:1:2 RATIO is best. Ratio isn't the same as the fertilizer's NPK %s. Examples of 3:1:2 ratio fertilizers are 24-8-16, 12-4-8, 9-3-6, all commonly used, but I favor the Foliage-Pro 9-3-6 for all my potted trees. It has many advantages over most other fertilizers and serves as one of the few fertilizers that provide all nutrients essential to normal growth .... a 1-stop nutritional supplementation program. That it doesn't contain urea and derives more than 2/3 of its nitrogen from nitrate sources is of significant value for plants grown under low light conditions, such as is normally the case for houseplants.

The average plant takes up about 6x as much N as P, and about 3/5 as much K as N (60%). The fertilizer you're using (7-5-6) supplies 3.26x as much N as P, so you can't supply enough N for the plant w/o supplying an excess of P. The fertilizer also provides 71% as much K as N, more than necessary, but not as significant as the level of P. It's not like your plant will get sick or die if you keep using the 7-5-6, but when you add up all the advantages of the FP 9-3-6, it's worth changing.

Yes, that's the usual spot. I tend to move it a bit further back during the summer months as it can get quite hot. OK, that pretty much eliminates sunburn as a cause of the spoiled foliage. Even in winter, if the plant is in full sun, you should try to have a small fan moving air in the room to help prevent passive solar (heat) gain.

Al

I managed to nurse it back to health and since the spring it has grown almost a foot and around 8 new leaves have grown.

It looks like the leaning tower of Piza but it's getting straighter again. Now I'm wondering if this pot is too small or if it's still ok.

Strong work!

Don't worry about the leaning - that can very easily be fixed by changing the planting angle when you pot up (to a larger pot) or repot (includes bare rooting, root pruning, and a change of soil).

Make sure you consider how tall you want the tree to be, then pinch the tip of the stem when it's at 2/3 of the ht. Example: If you want the tree to max out at 84" tall, pinch the stem when it's 48-56" tall That will give you the remainder of the ht in which to develop the canopy. Do that by allowing every branch to extend until the 3rd leaf is growing, then pinch the branch back to 2 leaves.

That will force new branches to grow in the axils (crotch formed by the branch and leaf stem) as you see above. The new protrusions in the axils of the mature leaves on the <i>Ficus microcarpa</b> cutting are branches. You can maximize branch and leaf density (ramification) by using this method.
Al