About to stump/regraft unknown citrus tree… thoughts on mandarins?

[a3pulley]

I have a citrus tree (at least 20 years old judging by google earth imagery) that produces small, bitter lemons (about the size of a key lime). I would like to stump and graft it with mandarins, but I was overwhelmed by the number of mandarin options on the UCR budwood order forms.

1) anything I should know about stumping and cleft or bark grafting this time of year in SoCal? I am a grafting newbie but have grafted avocados some.

2) what are your favorite mandarin varieties to eat and grow in SoCal?

Here is the tree in question:

[Galatians522]

My first recommendation is to try and find out what your rootstock is. Some mandarins are not compatible with particular rootstocks (Murcott on Swingle for example). There are some pretty sharp people on here who might be able to help you identify the tree of you post pictures of the fruit and tree

[70Malibu]

That tree rootstock looks almost like my volkamer lemon. The fruit shape is similar to volkamer. I can tell you which mandarins tastes the best in SoCal from my citrus fruit tastings from previous years and specifically last years.

1. Miho-Wase satsuma - taste test winner, 10 out of 10 ranking by 20 people at the tasting.
https://citrusvariety.ucr.edu/crc4047

2. Lee x Nova, also called US Superna- taste test winner, 10 out of 10 ranked, it was a tie with above.
https://citrusvariety.ucr.edu/crc3991

3. Xie Shan - very good, Millet said it took first place in his area citrus taste testing.
https://citrusvariety.ucr.edu/crc4081

checkout page 2 of this post below, I show the Xie Shan fruits on my trees.
https://tropicalfruitforum.com/index.php?topic=44898.msg442851#msg442851

The other citrus varieties I like from my trees are:
- Valentine pomelo, this year and last year it was a favorite (#2 rank) of everyone I share my fruits.
https://citrusvariety.ucr.edu/crc4182

- Cocktail/Mandalo, last year and this year, it was my #1 ranked fruit tasting by everyone I gave fruits. The only other variety that is better today in my taste test is the Golden Pomelo fruit (very hard to find this fruit).
https://citrusvariety.ucr.edu/crc3555

- Yosemite Gold, excellent taste, large flat fruit for a mandrin.
https://citrusvariety.ucr.edu/crc3975

- Gold Nugget mandarin, great taste, highest fruit production of all the mandarins I grow. Much better shelf life than Satsuma.
https://citrusvariety.ucr.edu/crc3913

- Shasta Gold mandarin, Brian says it's his favorite. Very large seedless fruit. I have not tasted a good one so I need to buy a fruit somewhere. I had this variety and I thought it was not that good and cut it off.

https://citrusvariety.ucr.edu/crc3973

https://tropicalfruitforum.com/index.php?topic=37493.msg573101#msg573101

- Sumo, Shiranui- this is a vigorous tree in SoCal, gets many large fruits. Taste wise, not really great, like a good orange to me. Any of the ones above is better tasting to me. My fruits never get high brix. Maybe due to not letting sit in the dark for 20 days after picking.
https://citrusvariety.ucr.edu/crc4249

==========
First as Sam say, make sure you find out what rootstock it is, I don't remember many mandarins or sweet variety of citrus I mentioned are grafted on the Volkamer rootstock. My Volkamer rootstock was use for the kaffir lime/makrut (use Makrut) tree I bought about 20yrs ago.

There is a rootstock compatibility table someone posted many times here before.

[a3pulley]

Thank you both for the responses! Kaz, assuming I can identify my rootstock or at least have some faith the mandarins would take, I will consult your list when I order budwood.

Is this the table you were referring to Kaz? https://growingfruit.org/t/subtropical-citrus-graft-compatibility-incompatibility-charts/17311

Here are some more pictures of the tree in case it’s obvious to anyone what it is…

[70Malibu]

Yes, that's the table, let me copy that now for my database.

Your fruits do not look like a volkamer. I don't know what it is. Let me post some of my volkamer fruit and leaves latter tonight.

Someone on the citrus side will know just by the fruits you showed. Maybe you should move this topic to the general Citrus section then you will get more knowledgeable people to answer your rootstock question.

[70Malibu]

Here's my Volkamer tree leaves and fruits.

[Galatians522]

Thank you both for the responses! Kaz, assuming I can identify my rootstock or at least have some faith the mandarins would take, I will consult your list when I order budwood.

Is this the table you were referring to Kaz? https://growingfruit.org/t/subtropical-citrus-graft-compatibility-incompatibility-charts/17311

Here are some more pictures of the tree in case it’s obvious to anyone what it is…

That does look like a Key Lime to me from the pictures. I have never thought of Key Lime as bitter, though. I really couldn't find much on compatibility for key lime. Maybe try a couple different varieties in case one is not a good combination.

[70Malibu]

Sam, you're right, looks like my key lime. Just cut some branches and fruits and it seems to match.

a3pulley, if it is a key lime, you should be able to smell the strong lime smell of the skin when you scratch it, and take a taste, should taste like a lime.

I'll post my photos later, but it does look like it.

https://citrusvariety.ucr.edu/crc1710

[70Malibu]

.

[a3pulley]

Wow, I am truly a forum noob. Didn’t realize there was a citrus board 🤦‍♂️

Maybe I had a bad fruit. I’ll try again tomorrow and see if it smells limey and tastes better.

[a3pulley]

You guys were right. I must have had a bad one or got some dirt in my mouth when I squeezed it in the yard. I compared it side by side with my Bearss lime and the fragrance and flavor are very similar.

[70Malibu]

Yup, I have both trees. I like the Bearss fruit better, larger fruit and more juice.

Just graft some branches of your bushy Key lime tree. You can graft any other citrus on the Key lime branches.

I have 20 different citrus verities grafted on my Bearss tree. Sanbokan is a vigorous one if you like lemon flavor that is only mild acid, almost like the NZ lemonade.

[a3pulley]

Wow, that was painfully expensive. I just ordered these from CCPP:

GOLD NUGGET MANDARIN, US SUPERNA (USDA 88-2) MANDARIN, MIHO WASE SATSUMA, VALENTINE PUMMELO HYBRID, XIE SHAN SATSUMA

Let us pray my grafting skills (or lack thereof) will not waste this budwood!

Thanks again to you two for helping me identify the mystery fruit and suggesting some tasty varieties that are proven in my area (Kaz, I think my climate is probably similar to yours. The city side of PV is quite warm for a coastal location).

[Galatians522]

You are welcome, I let Kaz handle the variety recommendation. Sometimes there is a significant difference in variety performance between Florida and California.