CITRUS FRUIT AND BLOSSOM DROP

Tales from a Desert Gardener
by Steve Fazio, Horticulturist

“My fruit tree is dropping all of its blossoms – my fruit tree didn’t bloom this year – fruit is falling from the tree.” These remarks are expressed by many gardeners in connection with citrus and deciduous fruit trees. What caused these problems? Some are related to cultural management practices, temperature; others are normal plant responses.

Citrus trees will cause the greatest concern for most gardeners – they will shed many blossoms and later in the season, fruit as large as walnuts will fall to the ground. All varieties of citrus produce more blossoms than the tree can possibly set – approximately 98% will fall even under the best cultural management practices. If 2% of the blossoms set fruit, this would be considered a heavy commercial crop. This is a natural behavior of the trees, but failure for 2% to set fruit is related to many factors. Late spring frost that occurs during bloom period causes a weakening or death of the abscission layer. This layer of cells connects the flower to the tree – sub-freezing conditions injure the cells, and blossom drop will result.

Trees that were not fertilized prior to the bloom period often drop excess number of blossoms, especially if soil fertility was extremely low. The tree is reacting in a natural manner – it is ridding itself of a burden. Improper irrigation is also responsible for blossom drop. Fruit trees in the blooming stage require very special attention in connection with soil moisture – they should never be allowed to stress for water – this will weaken the connecting layer. Trees should not be over watered at this stage – irrigation should be maintained on the same level used during the growing season – irrigate when soil examination reveals a need for moisture, but do it on a more careful basis during bloom.

Some varieties of citrus may fail to produce blossoms – gardeners will often state, “Last year my tree had a profusion of blossoms, and I had a heavy crop of fruit – no blossoms are evident this year.” This condition is common with some varieties of mandarins – the Kinnow mandarin is one of the main culprits. This condition is referred to as “alternate bearing” – a heavy bloom one year and none the next. This occurs on other citrus varieties, but not as pronounced as the mandarins. Commercial growers will often state, “My orange and grapefruit crop is on the light year cycle.” Others may state, “My crop is on the heavy cycle.” Trees that produce a heavy crop one year will usually produce a lighter crop the following year – this is alternate bearing on the light side.

The heartbreak of growing citrus is called “June drop.” This occurs when fruit the size of a pea or as large as a walnut fall from the tree. It is caused by high temperatures and low humidity – it will be evident starting in May and extending through the month of June. Trees should be checked at frequent intervals during the stress period for soil moisture – fruit drop is aggravated by moisture deficiency.

Harlow Gardens
5620 E. Pima St., Tucson, AZ 85712
(520) 298-3303

Comments

  • Posted: August 17th, 20128:07 am
    anchorwave2
    Said

    I live in Mesa AZ….This year my navel orange had no blossoms therefore no fruit growing. The leaves look green and shiny. I am expecting that maybe it could have been water as after I watered copiously the trunk sprouted lots of those little outgrowths of leaves.
    My question is this. I do not want to lose this tree. What is the best thing to do now to make sure it will be OK for next year?

  • Posted: August 17th, 201210:29 am
    anchorwave2
    Said

    It is a little unclear (not sure about why you were watering ‘copiously’ or exactly what the ‘little outgrowths’ look like) what is happening to your citrus. However, to make sure your tree is OK for next year, simply continue to water on a regular schedule and fertilize around Valentine’s, Memorial, and Labor Day. If you could send us some digital photos at contactus@HarlowGardens.com we could be more helpful.
    Thanks

  • Posted: April 25th, 201310:18 pm
    anchorwave2
    Said

    Hi im buying a trailer and there was some kind of citrus tree planted here for years it looks like. i want to know what kind? and how to care for it, so i can give me whatever it is, lemon, orange or grapefruit? dont know. it did start getting some green little (lime) looking fruit on it? but again dont know what exactly it is. please help. it is a tall tree.

  • Posted: April 30th, 20139:49 am
    anchorwave2
    Said

    Hello Jeanette,
    Some citrus are easier to identify without fruit than others. If you can bring in a photo and a 6″ (at least) piece of a small branch our Garden Wizards may be able to identify the citrus. Also, check for thorns, because this can help identify.
    As for care, all citrus in the ground is cared for in a similar manner. We recommend you fertilize in ground citrus three times a year – February, May and September. Our Garden Wizards will be happy to give you advice on fertilizers, watering techniques and general care. Hope to see you soon!

    Thank you,
    Cara

  • Posted: May 30th, 20133:06 pm
    anchorwave2
    Said

    I have old navel and grapefruit trees in my yard that produced many blooms in March and have a healthy fruit crop growing now (late May). I planted a lemon tree in the same area 4 years ago that started producing fruit last year, however this year the many blossoms fell off and there is no visible fruit on the tree. With that said, there is lots of healthy, new leaf growth. The trees are all watered weekly on a timer during summer months. They were also fertilized. I’m trying to figure out why the many blooms fell without fruiting. Your thoughts or suggestions are appreciated.
    Thanks,
    Nancy

  • Posted: May 31st, 201312:09 pm
    anchorwave2
    Said

    Hello Nancy,
    Usually a citrus not producing fruit is due to not enough water. Perhaps at some point this spring the tree didn’t get enough water. Your larger trees with more established root systems are less vulnerable to drying out. This could be why they have fruit and your smaller tree doesn’t. Trees can take years to fully establish.
    Hope this helps!
    Sincerely,
    Cara Bohardt

  • Posted: June 7th, 20138:31 pm
    anchorwave2
    Said

    I got a pot of Tangelo tree, it grows very healthy. It got lot of fruits but dropped off all for two years. I could not find out the reason. Please advice, thank you in advance.

  • Posted: June 12th, 20134:44 pm
    anchorwave2
    Said

    Hello there,
    If your citrus tree is dropping all of its fruit, the problem is usually not enough water. If the tree does not get enough water, it will shed its fruit to save energy for the rest of the tree.
    Thanks,
    Cara Bohardt
    Assistant Administrator

  • Posted: September 15th, 201311:39 am
    anchorwave2
    Said

    My lime tree is two years old. It has some curled leaves which I understand does happen sometimes, but some of the limes are turning yellowish on the bottom of the lime. I have fertilized according to schedule. What would cause this yellowing? We live in Surprise AZ so it does get
    HOT here! I water them in the early morning 6 days per week. Am I giving it too much water?

  • Posted: September 25th, 201312:31 pm
    anchorwave2
    Said

    Dear Myrna,

    Based on the information you provided here’s what I think:
    1. The yellow on the bottom of the limes are simply the limes ripening. Although most people think of limes as green, many ripen to yellow if left on the tree. When fully ripe they are much juicier.

    2. You probably do not need to water six days a week EXCEPT possibly if it is in a pot. However, overwatering would show up with the veins on leaves being green while the rest of the leaf turns yellow (especially new leaves).

    3. The best rule for watering is to water when the soil is dry about one inch down. If what you are doing now seems to work then continue. Be sure and begin to cut back on the water around mid-October so the plant can get ready for winter cold.

    My advice could be more specific with the following information:

    a. How big is the tree.
    b. Is it in the ground or in a pot.
    c. How long have you had it.

    Hope this helps,
    Bill Harlow

  • Posted: January 25th, 201411:23 am
    anchorwave2
    Said

    I have a mature Lisbon lemon tree. It produced copiously the first 7 yrs. 2 yrs. ago NO blooms at all. Last year, with increased fertilizers and water, it bloomed in the center, still no fruit at all. I use a citrus mix purchased from Lowes, water a lot, and still what am i doing wrong?

  • Posted: February 13th, 201412:02 pm
    anchorwave2
    Said

    It sounds like you are doing the right things. If you are from the Tucson Area, our citrus trees have been confused by two very hard freezes in 2011 and 2013. Hard frosts can disrupt the bloom cycle and cause the trees to not bear fruit. As long as we don’t have any hard frosts this year, you should get a good crop.

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