It would be nice to see a pic of the whole plant -- pot and all. When you repot, you run the risk of root damage. It can take as long as a whole season to recover from a lot of root damage. So we don't know how much damage was done in repotting. Or if the soil is too wet, or too dry. I would probably hold off on the fert for a while.

I repotted back in April (from the original pot that it was sold on) and won't do it for a while now. Only recently it started yellowing a bit (I was away for 3 weeks in end of July until August 7th but had a hoiuse sitter - I fertilized right before I left and about 1 week ago.

As I posted previously, I tend to water when the top 2-3 inches feel dry and loose. I drench with water until it runs off of the bottom. I would say I am watering on average about every 5 days since it's a very gritty mix and it's been pretty hot (85-95F) and it sits in a sunny area with mostly 11am to 7 pm sun). There is some shade from a big maple tree in the mornings but nothing too shady.

Ill try to take a picture of the whole tree

Here it is:

Sorry the green of the lemon tree might get lost a bit on the background.

It's sitting on a 10-11 gallon planter as of now - when it first came its roots were tiny compared to the height hence the reason why I kept the stick. I do shake it from time to time to encourage roots development. Also its been sitting outside sometimes with some pretty nasty winds - I believe i could actually remove the stick by now.

Here;s also a picture of the fertilizer and an upclose of the media:

I got this fertilizer since locally, it was the closest to the ratios I had seen around here about lemon trees - 3-1-2 I believE?

95º is getting pretty hot for a potted citrus. I think if you could move it into more shade, it might recover faster. None of my citrus get that many hours of full sun and they are doing great! I think 6 hours of unobstructed sun is plenty for potted citrus, but I'm sure some would disagree with me! Early morning until noon and then late afternoon sun seem to be fine.

While your fertilizer is 12 nitrogen, it says 8 of that is slow release which isn't so good as it's drops your NPK to 4-5-7 in immediately useable nutrients.

so should I hit it with something more... fast? What if I use this and dissolve it in water before each watering? that would make it available faster? Would I still keep the same amount/qty of fertilizer? For example dilluting 8-10 tablespoons in a gallon of water and then just water it?

I also have pure urea at 46-0-0 which i think there is nothing slow release there... i could probably use it to complement this one if needed.

How many lbs of actual nitrogen does a potted lemon tree need? 1lb? Also in a container environment i need to keep feeding it all year round correct?

So would it be better to spread that 1lb of actual N every 2 weeks? So 26 feedings, which would give 0.03 lbs of N per feeding and with a 12-5-7 fertilizer would mean 0.3 lbs of fertilizer - which is about 2/3 of a cup if Im not mistaken

Anyome? What is the best ratio/quantity to give it? Is this yellowing pattern a nitrogen deficiency after all? Thanks

The one yellow leaf is just an old leaf. The leaf is yellow because the tree removed all the nutrients from the leaf before discarding it to reuse. Nothing is wasted by the tree.

Citrus takes up nutrients in a 5-1-3, they are heavy nitrogen feeders. You would feed them all year long if unless you have them go dormant in the winter. Nutrient deficiencys can be from other factors besides lack of fertilizer. ( Ph, root rot, soil temp). I wouldn't add too much more nitrogen because the slow release will be releasing. I would check the roots and if they look good give the plant some water soluble fertilizer high in nitrogen at about half strength.

thank you silica. However most other leaves also are a bit yellowy. Are those fine?

Ken B, I knew they are heavy N feeders, so not sure I was giving them enough. I dont think I was, i was giving them only 2 tbsp of fertilizer, so last feeding i gave them 1/2 cup. I water them until water comes off at the bottom. The media is super drainy since it's very coarse and there is a lot of MVP in there

Thank you Silica. I've learned so much from you. Hu, best of luck to your tree.

thank you so much for the responses. I was just afraid of something going bad with the tree. IT has grown quite considerably since April and Im hoping it will transform into a nice bushy little tree coming next year!

There is another flush growth coming correct? I believe I read somewhere that lmeon trees usually have 2 growth spurts per season/year?

So a month has passed and there are still yellow leaves. I must say most are on the top part of the tree which happens to also be the oldest. On the other hand, there are a lot of flower buds coming in, I counted more than 50! I leave here a few pictures of the tree and their leaves:

i tried to add more picstures but for some reason my posts aren't coming through! not sure if it's because there is a limit of picture size or what. My whole post disappears and then I have to rewrite everything again (tried it 5-6 times)

Regarrding fertilizing timing, since this is in a container, and soon in about a month or so will start to go indoors, I need to keep giving it fertilizer correct? Most articles I have read state to stop feeding it sometime in October or so once the growing season is over, however, this will come into my house so shouldn't i keep feeding it? I dont have South windows so I am a bit afraid of the winter season. We do have lots of glass and big 10x6 windows both in West and East sides of the building. would that be ok?

Ok adding some images through links:

https://share.getcloudapp.com/yAul8Kyg

https://share.getcloudapp.com/KouwzA7x

https://share.getcloudapp.com/wbuP1z8v

https://share.getcloudapp.com/JrugAOn5

https://share.getcloudapp.com/jkuDrvE5

Your trees should do just fine in a western exposure with big windows. My own, personal, trees (I have 3-ish) live year round in a west-southwest picture window and bloom and produce fruit. I will add that their room stays between 62/70F in winter, 66/74F in summer thanks to central heat/AC with the winter temps dropping a bit more as the heating isn't as efficient in their room so I have to use a supplemental heater during the day. Also, they are far from any vents and the supplemental heater. I do fertilize year round every 2 months with a granular fertilizer, but I use a little less quantity in winter as they slow growth due to the shorter days. Silica had a good post about this on another discussion topic a few days ago.

Yellow Vein Chlorosis. Reduced nitrogen uptake. This occurs with the onset of cooler weather and exacerbated by your choice in potting soil. Be a winner, compost dinner, try rose soil next year. June is the time when you cut back on fertlizer!

Citrus, Cacti, Succulents, Photography · More Info

Lemon Lime Orange Zone, reduced nitrogen uptake means that I need to feed it more or take back? I assume its the latter.

Hi Hu

Yes, I would take back to slow down growth.

"Nitrogen is classed as a mobile nutrient, which means that plants and trees can move it from one part of their structure (leaves and branches, etc.) to another, away from places where it’s no longer needed and into new growth.

Since the nitrogen in the soil is less available in the cold seasons, citrus trees will mobilize nitrogen reserves from older tissues, redirecting them during the spring flush into new leaves and flowers. When part of the nitrogen of the leaf is translocated back into the tree because of inadequate nutrition, the result is yellow-vein chlorosis."

https://deepgreenpermaculture.com/2018/06/26/citrus-yellow-veins-on-green-leaf-in-winter/

June is the time when you cut back on fertilizer. ?

That does not make sense.

LLO, I know that soil temperatures can restrict nitrogen allocation for in ground trees. Container trees grow inside greenhouses, or homes during the winter months where the soil temperature always is above the cold restriction limit for nitrogen allocation. The problem as HU see it occurred during the heat of summer.

yeah that didn't make sense to me. why would i stop giving "food" to the plant if the indoor temperatures are within the growing temperatures? sure, it won't grow as much due to lighting conditions but i would assume i would have to keep feeding it.

HU, do you ever feed the tree its magnesium, Epsom salts (magnesium sulfate) is a good source of magnesium for a citrus tree. Dissolve 1-tbl spoon per gallon of WARM water and apply to the root zone every 3 months or so.

No i havent fed it magnesium yet. I was researching to see how much it would need and how often but never got any article/site that was definitive in terms of quantities. 1tbl spoon per gallon, should 1 gallon suffice as a carrier? what about iron should i give it iron as well or no need?

I do have Epsom Salts around so i can do that today!

From looking at your tree's leaves it looks like the iron is OK.

You absolutely don't have a magnesium deficiency but I wouldn't rule out toxicity until half-past tomorrow.

When you overwinter citrus indoors and keep fertilizing the plant it will continue to push out new growth. The plant will consume itself using mobile nutrients which will accelerate leaf drop and twig dieback.

Zone 9 you can sprint through the winter months indoors but in Zone 6 you have to be a distance runner and pace your plant through 8 months.

Your plant is going to go from a wet/cold/warm environment to a dry/hot indoor environment without much sun and it is going to hate it.

Giving a plant too much fertilizer is like giving an athlete steroids. It provides a quick benefit but it has long-term effects especially indoors.

Here is a brand new bag of PRO-MIX. It has enough nutrients to last 6 months. The key to growing indoors is low EC.

Citrus, Cacti, Succulents, Photography · More Info

i should say that our indoors is not dry. Our furnace barely runs in the winter due to very high amounts of insulation, and the furnace never gets a chance to dry the air out. Our humidity levels inside the house in winter time is 50-55%

wasnt able to find that promix bag you have where can one find it?:

HU Any Cannabis grow store in any city has good quality soils. Fox Farm Happy Frog or Fox Farm Ocean Forest will work well. Ideally look for a mixture with 60% maximum humidity. They all have a good PH. 50-55 RH is better than many. It all depends on the Temperature/Humidity combination.