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marilano

Tangerines splitting and falling off tree

marilano
13 years ago

I live in northern California (near San Jose), and I have a mature semi-dwarf tangerine (or mandarin?) tree that produces a big crop every year. The tree is probably 30 years old. This year, starting in about mid-October, lots of small green and, more recently, semi-ripe tangerines are splitting; most of these then fall off the tree. This started happening well before a couple of recent nights when we had an hour or two of just-below-freezing weather (which did kill many of my impatiens). We've had a good amount of rain in the last few months, although I probably wasn't watering regularly enough during the summer, and I also wasn't fertilizing as often as I have in most other years. But my grapefruit tree isn't having this problem and has lots of healthy looking fruit on the tree that seem to be starting to ripen. My lemon tree rarely keeps the fruit on the tree long enough to even ripen fully, but the lemons don't split--they just fall off a little green. I've done a little research on what may cause citrus fruit in general or tangerines in particular to split while they're still on the tree but I haven't found a clear reason for the splitting, or, more importantly, any ideas for how to prevent further splitting. Does anyone out there have ideas about this? TIA for any replies.

Comments (5)

  • bahia
    13 years ago

    It probably has the most to do with inconsistent soil moisture, and going a bit too dry alternating with heavy rains. General advice is to try and keep the watering up in the drier months, maybe also mulching more heavily to minimize the soil drying out. A slower time release fertilizer application of regular applications of a liquid fertilizer may also help counteract this during the warmer months.

    I don't know what is going on with your lemon tree, I only note the young fruit falling off on lemons that are not getting enough sun. Do you notice if you lacked for bees to pollinate the flowers this year? That could be part of the issue as well.

  • calistoga_al ca 15 usda 9
    13 years ago

    Generally soil in the San Jose area is good for trees and is well drained. You may be dealing with an exception. Grapefruit are much better in dealing with bad growing conditions with a better root system. Citrus are not dependent on insects for pollination, and I would look to the soil for the cause of your problems. Al

  • eloise_ca
    13 years ago

    Do you have squirrels in your area? Past few week, I've noticed quite a few walnut-size green oranges on the ground and didn't know what was causing them to fall off the orange tree. A couple of days ago, I saw a squirrel cutting a green orange, dropped it, and then reached for another. It can't be that they are hungry because I constantly see them going next door and getting apples, plus anything else they can carry!

  • marilano
    Original Author
    13 years ago

    Thanks for the replies. For some reason, I wasn't getting emails from Gardenweb noting that there were responses to my post. Anyway, to answer a few questions: I do have lots of squirrels in the yard, but I don't think this is the problem, given the way so many tangerines are splitting while still on the tree and the large number that are falling off after splitting. I've seen plenty of other fruit in my yard over the years that's been partly eaten by squirrels (my plums in particular), so I think I can tell the difference. As to bees, I think I've seen some, but "Calistoga" says citrus don't need them to pollinate. I do get a fair number of hummingbirds. My lemon tree gets the least sun of the 3 citrus trees in my backyard (since the sun is blocked by a taller building for most of the day), so I've always suspected that's the problem causing the lack of ripening of the lemons. I do use the fallen lemons, after letting them ripen on the counter after I bring them in. The lemon juice is okay for cooking and putting on veggies and salads, but not great. My 3 citrus trees are in circles of ground (with concrete trim) about 3 feet across, in a yard that's otherwise bricked in, so it's hard to water the entire root system. I usually have tried to deep water once/month in the spring, summer, and fall, but didn't keep that up as regularly this past year. And I didn't fertilize enough, I think. So I'll try being a better gardener this coming year :-) and hope for the best. marilano

  • hoovb zone 9 sunset 23
    13 years ago

    Try also mulching the root zone with a good compost (keep the mulch from contacting the base of the tree--leave a few inches bare). This will keep the root system a little cooler and more moist, and enrich the soil as well.