If you leave them on too long, you can encourage alternate bearing--light crop one year, heavy crop the next.

Thanks for the responses.

To Fireballsocal, what did citrus trees do for millions of years before anyone was around to pick the fruit? Maybe citrus was cultivated along with other agricultural products and didn't really produce the fruit we know today. In any event, yours is a response worth investigating.

And bounty, would it be easier on the tree if it didn't have to produce a full tree-load full of fruit every year? This tangerine tree has been around for 35 years or more and I'd like to do whatever causes the less stress on it. It naturally seems to have light years and heavy years of fruit production. Normally I pick most of the fruit but I've let it go for some reason this year.

Thanks both of you,

Mike

Well, citrus trees millions of years ago (not sure they were actually around that long ago) provided fruit for wildlife, so, they were most likely picked clean, thus avoiding mummy fruit for the most part, and preventing themselves from going into a protective alternate bearing state :-) And, the occasional mummy fruit that may have harbored fungii and other pathogens probably aided in different cultivars' abilities to eventually become resistant to certain pathogens, so in nature, not always a bad thing. You shouldn't leave any fruit to rot on a tree, citrus or otherwise, as it can become a repository for disease. Same with deciduous fruit trees and dropped leaves.

To your second question - some cultivars are simply extremely prolific. They are bred this way because it means a larger commercial crop for commercial growers. If you're overwhelmed by your tree's bounty, you have some options: Pick all the fruit, eat what you want, put up what you want, and give the rest away to a worthy cause (food banks would love to take your extra harvest). Or, if you're not feeling so magnanimous, simply thin your fruit at about pea size. And, if there is still too much, thin again at golf ball size to the amount of fruit you think is reasonable for your household.

And, many mandarin cultivars (the correct term for your tree) tend to have some degree of alternate bearing as you are seeing - heavier years and light years, and this can be intensified if you allow too much fruit to ripen during one season, or leave ripe fruit on the tree for an extended period of time.

Patty S.

Citrus as we know it didn't exist millions of years ago. It's been cultivated and bred for hundreds of years. Remember, there is no such thing as a completely natural orange. They are a hybrid of a mandarin and pomelo probably (Wikipedia).

Regardless, a citrus tree left to its own devices will probably be ok. It won't produce the best or the most fruit and probably won't live as long of a life as it could due to diseases or insects. Pulling the old fruit just goes a long way to keeping the tree as healthy as it can be.

Well thanks everyone. Question answered. I'll get out there and clip those mandarins today and find someone to appreciate them.

This conversation reminds me, especially Fireballsocal's location in San Bernadino, of a Huell Howser 30 minute PBS program which visited the Citrus State Historical Park in Riverside. Looking it up just now I'm reading it is 248 acres and its fate is somewhat uncertain due to budget issues. I can imagine its fate is also somewhat uncertain thanks to developers lusting after the acreage. For anyone interested in citrus I think this would be a fascinating place to visit. Meanwhile, the Huell Howser program is probably available for sale through KCET or PBS online. We all sure miss Huell.

Mike

There is a group of gleaners that will come and pick your fruit.

There is a southern college,name?, that has all of Huells shows online for free. I sure miss him too.

Tom Spellman of Dave Wilson nursery visited there as well. His is a shorter video but still a nice insight as to the grounds. My dad wants to tour the property so we may go once the trees start blooming.

Mike, I've been to the Citrus State Historical Park many times, just recently about a year and a half ago or thereabouts. It is very close to the UC Riverside Citrus Variety Collection. I actually lived in the general area for several years. Very fun place to visit, the tours are wonderful, you get to sample ripe fruits as you go on tour. Trees are blooming now, and citrus is ripe, now, so this is the time to visit.

Patty S.