Thank you for the info Margaritaville! I found an online supplier with good reviews, but I haven't looked at local markets. I will give them a try first.

Do you use 5:1:1 or a commercial mix for your seedlings?

I wish I could tell you I use some special mix, but no, I just use my regular mix (but not straight out of a bag), and with some added coarse sand and perlite. The reason Sour or Bitter oranges (Citrus aurantium) are commonly available in Hispanic markets is because the fruits (naranja agria), are used in the Caribbean as meat marinades (mojo sauce). Curiously, it's grown in the south of Spain, but have read that they are not really used in Spain, but the fruits are shipped to Britain and the British make it into marmalade. The tree itself is rather thorny.

It’s known as Seville orange : hence Seville orange marmalade made in Britain. it is fantastic, try if you can find it.

in Seville they actually grow on the streets and are loaded with fruit in November. Quite a sight!

NYC supermarkets usually have british jam. and Publics in Miami carry fresh fruit too. It makes great 3 citrus marinade for ceviche (lime, grapefruit and sour orange).

here’s a great info:

https://minnetonkaorchards.com/seville-orange-tree/

this reminds me to go get it and sprout some seeds too..

now i need to find out how soon will it flower from seed. any idea?

i have a calamondin from seed now 13 yrs , still no flowers..

I grew a sour orange tree from seed. I planted the seed in August 2006 . The tree first fruited in 2018..

Wow Silica, that's a long time! I know it takes a while when growing from seed, but I didn't realize it would be that long! I am mostly interested in growing rootstock, so it's okay if I don't make it all the way to fruiting ὠ9.

i read that calamondin can fruit from 7-10 max 15 years from seed. i hoped for 7, but.. :)

here is a very good citrus site and sour orange info with pics.

Just wanted to add that i sprouted my calamondin seeds in December in NJ and grew them indoors: my original bought Calamondin tree dropped all leaves from severe mite infestation when i was away.

now i know that it can regrow, but then i chucked it (going into winter indoors..)and i had only 1 fruit left. 2 seeds both resprouted: if multiples select the biggest: it is a copy of mother plant.

they can sprout within a week when fresh.

they went thru that and many other winters in part sun on west window just fine.