Thanks Steve. I've tried a couple nearby but they only have sweet oranges. There are still many more to look at. Many neighborhoods here have ornamental citrus trees as part of the landscaping, but no one seems to know what kind of trees they are, just that the fruit is bad. I'm going to try and get confirmation from a local parks dept.

"...but no one seems to know what kind of trees they are, just that the fruit is bad...."

I wonder what else it could be other than sour orange? You should ask for fruit. Believe it or not our local Giant food market has sour oranges for sale as well.

Hi Travis, Try Dave's Garden Trade Lists.

Dave's Garden Trade List

This used to be a very active board for SW Gardeners (and many others as well) but Dave sold to a large conglomerate and the SW Gardening board is practically silent now. Too bad, it was a great resource and chat site.

Thank you Dave and Mary. I will check the Trade List. I wondered the same thing Dave, but I didn't know if there were other ornamental oranges that don't taste good. I thought it likely they are sour orange, but I didn't want to spend the years to grow seedlings and try grafting on an unknown rootstock.

Yuzu may be another option. It is kind of like sour orange, except less juice inside, the peel is somewhat mildly edible, and the plant has lots of very long spiky thorns.

There are loads of fruiting sour orange trees planted in Tucson. I would imagine the trees are sold at nurseries there too. In any case, if you go by there you can see many beautiful old citrus trees, including sour orange on the UofA campus. The trees have name tags, too, so you can be sure about identification!

mexican/latin markets might carry it too: it is widely used in cooking. It is seasonal, just ripening now in nov-dec. best to get fresh fruit as seeds wont sprout once dry: sprout ASAP.

i just read that cochinita pibil (famous pork dish) is made with sour orange , had it many times but never knew!

apparently there are 2 kinds of Seville orange: original with rougher rind and hybrid with smooth skin. smooth skin is widely grown commercially, but rough skinned one is more aromatic. both are used for marmalade in Britain.

you might guess: i am a foodie 😁.

i use the juice from fruit for marinade for fish and ceviche. it is also widely used in Cuba. you can use the juice for cocktails too. In Miami they even have it in better Publix. so to say that fruit is inedible is not quite right. ghe rougher skinned one is more bitter, but then that is the one they prefer to use for marmalade.

and i just adore yudzu! but that is only found in japanese markets even in NYC. would it sprout true from seed? just curious..

Thanks for all the help! The parks department for a nearby community confirmed for me that the orange trees on the streets are sour oranges, so I will look for ripe fruit as I drive through in the next few months.

I saw two at Whitfill on Glendale today.

Thanks Sarah. I found some nearby and grabbed a few last month. I'm germinating the seeds as we speak ;)

I got a few at local market and put them in the fridge.. a month later took the seeds out of one and have been keeping them moist in barely any water for a month now.. no sprouting yet. the box was from Mexico, where they traditionally use them for sauces/marinades. i still have more in the fridge. do you think they can sprout after chilling? or should i get a fresh batch ?

I also got a few satsumas.. and found 1! seed, also soaking in 1mm water with a drop of peroxide.. been a month, no sign of sproting either. same with kumquats (oval ones).

should i transfer into ziplock in moist napkin instead? seeds are firm, no mildew, looking good. temp about 75f.

@petrushka (7b) I have only germinated seeds while they were fresh. I don't know how keeping them in the fridge will impact success rate. Most of the seeds I harvested were not viable. You can test this by putting them in water. If they float, they go in the trash. Then I let the sinkers soak overnight to soften the gelatinous coating. The next day I rub them in vermiculite to scrub away the coating (optional step). Then I take little baby fingernail clippers and clip the pointed end off the seed, then peel off the hard shell (also optional, but will speed up germination time). Once I planted these directly in some fast-draining potting soil and covered with a plastic wrap. I had several sprouting up within about 2 weeks, but it was also gnat heaven and the sprouts shriveled and died within a few hours of removing the plastic wrap (I suspect their fragile roots could not keep up with the rapid adjustment from humid to arid). So, to avoid any potential climate changes and an abundance of gnats, I do not plant directly in potting soil. I place the de-shelled seeds on a paper towel folded over itself, mist the paper towel with water, and seal that in a plastic bag. Every few days I make sure the paper towel is still moist--rewet as necessary. You should see roots popping out within a week or so. Once the roots get to be at least an inch long, I plant in potting soil that is kept moist. Another week or two later and I see sprouts emerge.

TLDR: That is my process and timeline. If you did it differently without success (e.g., didn't check for viability by the float test, or didn't speed up the process by removing the shell) then I would give it a shot with the seeds you already have. Someone else with more experience than me may be able to tell you if refrigerating the fruit will have impacted the seed viability. I don't think it would have, but I could be wrong.

@petrushka (7b) Are your seeds floating or sinking? See above, if they are floating you probably won't have success. Also, optimum temp for seeds to germinate is 86F. It can certainly be done lower (my home is kept at 73F right now and my seeds are germinating), but the higher temp will quicken the process and up your odds of success.

I germinated mine in my furnace heating duct at the floor outlet.

They were not floating, so they should be good. long tume ago i sprouted fresh calamondine seed in moist napkin like in 5

days, without removing the seed skin. i’ll do that on some and put them in moist napkin.

there is plenty of sour oranges here in the market, si i can get fresh ones too. i’ll look at green market for local too: those should be super fresh: they are slso used in cuban cuisine , so they always have them in Miami!

i sprout lots of tropical seed of all sorts. i keep the seedlings under tent for a long time, they grow very slow (shrubs/trees). i have 2 tree seedlings 1 year old still tented. untenting invariably dries them up. although i poke holes after some time for a little ventilation.

I need to find my heat mat ..but then i really havevto watch them: they can dry up very fast!

Bottom water, they can drink up what they need when they need it. That's what I do when starting seeds.

When germinating Citrus seeds on a small scale, I place the small pots on heavy aluminum baking trays. The trays are on top of the heating mats. To prevent overheating the media there's a thermostat probe embedded deep in the media. I use 1 thermostat per baking tray I've lost seedlings to overheating when the heating mat temperature was unregulated.

I also germinatine the seeds at 86° and almost always see the first germination at 7 days. I've never used the moist towel method, as it seems to be an unnecessary extra step. There is less decay at 86° than at cooler temperatures, but avoiding excess moisture is very important, perhaps more important.

The purpose of the aluminum trays is twofold, to increase temperature uniformity and to contain any spilt water before it gets to the heating mats

@herman zimmerman I first tried planting the seeds directly in soil and covering with plastic wrap to maintain moisture. That turned into a giant gnat problem, as well as the seedlings all wilted once the wrap was removed. The paper towel/plastic bag is to allow for moisture without corrupting soil media with gnats, and avoiding dramatic humidity shifts when the wrap is removed. If you can plant directly in the soil and not cover the media, then I agree it's an extra step (although it does allow you to only plant seeds that successfully germinated). I read mixed results with planting directly and not covering. Do you cover your seedlings while germinating?

I initially covered them with a styrofoam sheet. At 7 days ít's replaced with a clear piece of polycarbonate sheet kept about 6" above the pots. Led lights are placed about 8" above the polycarbonate sheet. After germination is complete, the polycarbonate sheet is removed provided the ambient temperature is warm enough. I don't have any experience with fungus gnats, perhaps due to doing the germination during Winter.

Planting direct into any medium seems to work well. Also, the damp paper in a plastic bag also works well. I normally always peel of the testa (outer coating). I have a mature in ground Sour Orange tree so I can get a lot of seeds.

Pots placed on aluminum baking trays with thermostat probe in media.

LED lights above the polycarbonate sheet.

Germination box under normal lighting.

Some of the emerging seedlings are nucellar, too soon to tell what percentage.