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silverada_gw

Morus nigra strange looking fruits

silverada
10 years ago

Our approx.18 year old Morus nigra "King James" is a big healthy tree and used to produce wonderful fruit. For the last 5 or so years, it has produced these strange looking things at the same time as the leaves are opening (way too early for a mulberry to fruit). Some will have little white threads emerge and then they all just dry up and drop off. (I have more photos). Later in Aug. there may be about a half dozen real mulberries but no crop as such. It's been suggested that the tree has reverted to being a different sex than it was formerly. Can anyone suggest a source who could advise me how to persuade it to make fruits like it did before? There hasn't been any change in its cultivation or environment other than the vagaries of the seasons..

Comments (15)

  • silverada
    Original Author
    10 years ago

    Thanks for your interest. I looked at the site and can understand why you would think that, but our tree used to produce rounded fruits in common with all black mulberries her in the UK. Also, these things come just as the leaves are opening in May. Not typical mulberry behaviour, I feel.

  • lucky_p
    10 years ago

    I've seen M.rubra 'switch genders'.
    There was one nice young tree here on the farm that I noticed producing a decent crop of fruit one year - but on visits in subsequent years, no fruit - or only staminate blooms.

    So far as encouraging a switch back to fruitful productiveness... I don't know - unless you do something to damage it in a non-lethal manner. Have seen non-productive, senescent trees of numerous species that put forth a heavy crop following HARD pruning, or being subjected to hurricane-force winds that came close to toppling them(while also toppling some of their contemporaries).
    Or, you could, as some old-timers might offer, beat it with a mallet.

  • fabaceae_native
    10 years ago

    You're wrong about the timing silverada, as the flowers that later become fruits are produced with the first new growth in spring. This is why I think lucky is right on with his suspicion. Everything in your picture looks normal, except that your Morus nigra should be producing rounder female flower clusters, instead of those elongated male catkin-like ones.

    You can see (barely, I apologize for the poor quality of the image) in the pic of my 'Black Beauty' Morus nigra, which is probably not as far along as yours, having just popped leaves a few days ago, that the flower clusters are already present (just below the largest leaves at center).

    Lucky is probably right about the switched gender... I hope it is not permanent.

  • fabaceae_native
    10 years ago

    Here are some better photos for you, both of Morus alba.

    First, a female just leafing out... Notice that you can already make out the size/shape of the mulberries to be, even though what you are looking at are actually aggregates of flower buds and/or opened flowers!

  • fabaceae_native
    10 years ago

    ... And here is a picture of the male inflorescence. Notice the one near the center that has yet to open looks very similar to the picture you posted...

    You can easily confirm the sex of the flowers when they open with the aide of a magnifying glass (just compare to online images of staminate and pistillate flowers of Morus).

    Hope this helps...

  • silverada
    Original Author
    10 years ago

    Thanks lucky p and fabaceae.

    Re lucky's advice about a shock: I'm thinking about pruning it hard next winter, in spite of all the literature advice being not to do so after a certain age for morus nigra. There's nothing to lose since I don't need a non-fruiting mulberry, but I would like to be judicious about it for the best chance for success. Any ideas about how hard to prune or what diam. branch at which to stop? Do you know of other ways to shock the tree into another gender change? Gross feeding?

    Re fabaceae: you're right about my being wrong about the timing. The aberrant tree has 2 female flowers on it among the hundreds of male ones right now. As well, our other, younger, morus nigra has loads of female flowers this year, hooray.
    Hope we get some ripe ones before the birds this summer. I used to erect a tent of tall poles with balls on top to net the tree. What a palaver.

  • silverada
    Original Author
    10 years ago

    Fabaceae - re your photos, do you mean that there can be both male and female, in separate, complete forms on the same tree? Quite honestly, I don't get it about the tree being self- or wind-pollinated. Does it mean that only the female flowers can self-pollinate, because clearly, the male inflorescences can't produce fruit.

  • fabaceae_native
    10 years ago

    Unlike most familiar garden flowers and fruit tree blossoms, which have both male and female parts, mulberry flowers are unisexual. And as far as I know, most mulberry trees are typically dioecious, meaning they have either male or female flowers only. Obviously there are aberrations like you're experiencing, and some named varieties are bisexual trees that pollinate themselves by producing a few male flowers along with the female ones.

    Morus nigra varieties are self-fertile which means that a lone tree will form fruit (seedless) without having any male flowers on it or anywhere in the vicinity. Most wild Morus species need to be cross pollinated (by the wind blowing pollen from male flowers on one tree to the female ones on a different tree) in order to form fruit.

  • yukkuri_kame
    10 years ago

    We have a big old male which is naturally fruitless. As noted, the catkins come out with the leaves.

    Late this winter I grafted onto it scion from lavender mulberry, pakistan white & early white - obviously female.

    The early white came in early with a cluster of the biggest mulberries I've ever seen. The lavender are just about ripe now. Nothing from the Pakistan, which hasn't put out a lot of growth yet, but looks like a healthy enough take on the graft.

    I'll be looking to add more varieties this coming winter/spring.

    So, if your tree really has gone over, find some scion wood and graft, baby graft. Maybe combine grafting along with the hard pruning, as suggested. Even if the shock tactics don't cause it to gender bend again, the grafts should take off with vigor.

  • silverada
    Original Author
    10 years ago

    Holy smoke, I'd better start a search on how to graft. Being of an advanced age, I wonder if it's worth it -how long would it take to get a decent bowl of fruit from a grafted limb?
    I don't know if anyone is continuing to read this thread. Is it better to request direct email answers and respond to each individual who replies to my query?

  • lucky_p
    10 years ago

    Silverada,
    Grafted mulberries fruit quickly - I've even had scions push flowers from the outset - though I always pinch them out, as I want that graft to put all its energy into callusing in and pushing growth the first year.

  • rmaich
    10 years ago

    Silverada - I just discovered this posting today. I hope you have not followed the advice given to you by some and destroyed the branches that produced these staminate (male) blooms. Morus nigra is a sterile tree - the result of an ancient hybrid that occurred thousands of years ago between trees that no longer exist.. It exists today only due to vegetative propagation over that time period. Bud mutations have resulted in the several different cultivars that exist today, but they all trace their existence to a common ancestor. Morus nigra does not normally produce male blooms. It normally produces only female flowers, and fruit, without the need of pollen. You may have a tree (or a branch on that tree) produced from a bud mutation that has caused the tree to produce male flowers - something possibly not seen before on a Morus nigra tree (or seen only rarely). If these flowers produce viable pollen, it might be possible to use this pollen to produce improved varieties of mulberries. This is very exciting to me. If you still have branches producing these flowers, I would be extremely interested in receiving dormant cuttings from these branches for propagation. It may be too late this year to take cuttings (if the buds have begun to swell or open) but if so I would be still very interested in receiving cuttings this coming winter. Please contact me directly. My email address is: rmaich@pacbell.net Thank you very much.

  • fabaceae_native
    10 years ago

    rmaich:
    That's fascinating stuff... I never heard the origin of M. nigra explained like that before, but it makes perfect sense! So are all the varieties of M. nigra, including more recent ones all just bud mutations?

    What do you think are the chances that Silverada actually has a Morus nigra that produces male flowers then? I hate to be pessimistic, but it seems like something else must be going on, and/or he/she does not actually have a nigra...??

  • rmaich
    10 years ago

    Morus nigra, the "Black" or "Persian" Mulberry, is referred to as the "Shah Toot" or "Shahtoot" in ancient (and I believe modern) Persian, which means "the king's or 'superior' mulberry." It is my understanding that there was originally only one Morus nigra tree, which is believed to have been grown in the royal gardens of a Shah in ancient Persia (I've never heard speculation connecting it to a particular Shah or century, but references to it go back thousand of years). [It may actually have originated in pre-history.] Its genes are unique, so all varieties of M. nigra are the result of bud sports with relatively minor mutations. The word "Black" does not refer to the color of its fruit, but rather to the color of its dormant buds (in winter) which are uniquely black. Unfortunately, many people refer to any mulberry with black fruit as a "Black Mulberry." This is an incorrect usage. M. nigra is genetically unique in that it has 308 individual chromosomes - 154 chromosome pair (n=154). Mulberries in general are diploid plants with 28 individual chromosomes - 14 chromosome pair (n=14), so you can see that M. nigra has some remarkably complex generic history behind it. It is believed to be a complex hybrid who's ancestral species are extinct. The photos posted by Silverada show leaves that appear to be M. nigra. If he/she can tell us the color of the buds on the dormant tree, it would answer your question. I have not yet heard back from Silverada, so I can only hope for an answer at this point. Of course it is possible that the tree is producing male flowers, and that they are sterile and produce no pollen. I just don't have enough information at this time to guess.

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