Jason Delaney, Missouri


February 22, 2012

Categories: Autumn Blooming Daffodils, Diseases and Pests, Virus

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Keith’s UV-imagery post got me excited… so I want to share an image that I use in programs and educational exhibits. It is comprised of
different examples of daffodil foliage taken from the Missouri Botancial
Garden’s collection. I find it very useful as gardeners frequently question the health of their plants and often diagnose their situation incorrectly.

(When looking at the image, the left most example would be #1, then #2, #3, and #4 on the far right,  respectively.)

Example #1 represents Narcissus Yellow Stripe Virus (NYSV). NYSV is easily distinguished by its irregularly positioned yet often precise linear designs in the cell walls of the foliage. Some cases are much more vibrant than this, others far less noticeable. Look for the
distinct vertical lines.

Example #2 is what we would visually consider to be “healthy” foliage.
It is smooth and evenly colored for the length of each leaf throughout
the entire plant. As daffodils go, foliage color can range from
glaucous, bluish-green (such as ‘Maximus’, or ‘Gin and Lime’), to a very
rich green (such as ‘Geranium’), to very dark green (such as x
intermedius), to yellow-green (such as ‘Green Fire’, or ‘Verdant

Example #3 is early emergent frost damage on the leaf tips. This is a
tazetta whose foliage emerges in the late autumn or early winter and
‘burns’ during repeated freezing. Typcially, it is non-detrimental to
the plant, though some varieties in my climate (‘Gloriosus’ and
‘Avalanche’ immediately come to mind) tend to waste away after several
years of repeated damage. (NOTE: Frost and freeze can completely kill
foliage; when this is the case, the foliage usually looks brownish to
blackish-tinged and lies flat to the ground, redolent of cooked spinach
in the worst of cases. It rarely recovers in that season and it may
take a couple of years for the plant to recover. I’ve attached a
separate image of this, supplied by-I think-Mary Lou Gripshover to
Daffnet some time ago; apologies if photo credit is incorrect.)

Example #4 is cultural damage. This daffodil clump became entangled in
neighboring crinum foliage-the clump pushed through the crinum’s leaves
but couldn’t free itself entirely, and the section that was not exposed
to light had this blanched effect. This is not disease. (This example
also shows tip damage from frost.)

If anyone would like the full-sized files for their programs, please
e-mail me privately and I will happily share.

All best,


Jason A. Delaney | North Gardens Supervisor and Bulb Collections
Specialist | Department of Horticulture | Missouri
Botanical Garden


10 responses to “Foliage”

  1. Phyllis Hess says:

    Thanks Jason very informative!!!

  2. Peter and Lesley Ramsay says:

    Hi Jason – excellent illustrations of daff foliage. I agree with your
    diagnosis – the only bit I would add is that sometimes rapid growth will
    create lemon rings on the foliage. Once full photosynthesis takes place
    these disappear. The foliage doesn’t need to be entangled in another plant
    for this to occur.

    Do you have any photos of mosaic virus? Hunter’s research which the ADS
    commissioned some year’s ago demonstrated that this form of virus caused
    colour breaking in reverse bicolours. Many growers ignore it also
    disappears over time.

    I have begun collecting info for a revision of the NDSNZ cultural manual
    which I wrote in 2004. Would I be able to use your photos, properly
    acknowledges of course?




  3. Donna Dietsch says:

    Hi Jason,
    I received a tip from Sir Frank Harrison of Ballydorn Bulb Farm in No Ireland
    (explanation for those who don’t know who he is).  He told me to take the dead
    tip of the foliage off from those, like Avalanche, that  burned from freezing. 
    He said to grasp the leaf with thumb and forefinger and quickly pull upward to
    snap the top of the leaf off.  He said that fungus would  otherwise form on the
    necrotic tissue and rain would wash the spores down the leaf and into the bulb. 
    He said it would cause the bulb to deteriorate over a period of several years. 
    I have faithfully done this to my clump of Avalanche for probably 15 or more
    years and the clump is still vigorous.  He was my daffodil breeding mentor and
    we coresponded for many years until his death.  In that time, he never gave me a
    growing tip that didn’t work.  Have you ever tried this?

  4. Sarah Bentz says:

    Donna, Thank you!
    This condition is most likely going to happen here in NE PA this Spring with temps in February approximately 4 degrees above average for Jan/Feb, which doesn’t sound like a lot, but that is an average. We’ve had some really warm days and very little snow! My foliage is between 4” in cold spots to forming buds on south-facing, near the house bulbs. I wanted to dig some up, repot them and bring inside and actually joined daffnet to see if that would work, but my responses lead me to think it would set them back quite a bit and I just need to patiently wait for them to bloom outside, which now might be sooner than later.
    Thanks for giving me a strategy for when we get an extended hard freeze, as I can’t believe we won’t. It’s been a freaky weather year with a huge snow fall in October and then…next to nothing (say 5” total) all winter!
    Mother Nature is giving us a head-spinner.
    ~Sarah Bentz

  5. Ted Snazelle, Mississippi Ted Snazelle says:


    Thanks for the photos.  The first one is great.  As a professor, who teaches more than doing research, the first daffodil photo makes the point, “A good picture (illustration) can be worth a thousand words!”

    Thank you!


    Theodore E. Snazelle, Ph.D.
    101 Water Oaks Drive
    Clinton MS 39056-9733

  6. Becky Fox Matthews, Tennessee Becky Fox Matthews says:

    Thank you very much, Jason, for posting that daffodil foliage image. I would like a copy of the hi-res image to add in to presentation on growing daffodils along with the saved email text as a key. I have a patch of Minnow that often has tip frost damage similar to image 3.

    Twelve years ago I also planted a patch of 20 bulbs of Avalanche that are frozen back almost every year, worse than image 3, but not usually as bad as the second photo, though the bulbs still persist. While the patch puts up buds every year, I estimate I see a good bloom from them maybe once in 5 years, if that often. Perhaps someday I will dig them out and send them to someone whose climate is better for them. I have heard that Avalanche might do better not only further south from here, but also further north, where supposedly they would not break ground until much later in the season. I must go look at them this morning before work to see if the one more night of freezing
    temperatures (I think it got down to 28 degrees) we saw earlier this week did them in once again.;->

    I believe we’ve had about 3 days of winter here so far and the weather channel is predicting 75 degrees for a high today!

    Becky Fox Matthews

    American Daffodil Society logo
    Becky Fox Matthews
    / 1^st //Vice President/*
    American Daffodil Society, Inc.***


  7. Jason Delaney, Missouri Jason Delaney says:

    Donna, we do it only for aesthetics at the Garden. On the PHS farm I
    leave Mother Nature to handle things accordingly.

    I’ve noticed an extraordinary amount of sap oozing forth from the leaves
    when these brown tips are pulled, so we’ve adopted a strict routine of
    Physan (http://www.physan.com/) disinfectant and disposable nitrile
    gloves usage betwixt the different cultivars that we tidy, to reduce the
    potential spread of disease. Brown tip removal is not a practice I’ve
    recommended to our visitors, much the same that we say for deadheading
    daffodils, that it’s unnecessary-we don’t deadhead, save for a few of
    the fertile jonquils that would otherwise seed themselves into oblivion.

    At the Garden, ‘Avalanche’, ‘Martinette’, ‘Golden Dawn’, ‘Pappy George’,
    ‘Minnow’, some years ‘Kokopelli’, some years ‘Geranium’, ‘Odorus
    Rugulosus’, ‘Falconet’, ‘Hoopoe’, ‘Kedron’, some years ‘Chinita’, and
    ‘Suzy’, are all regular contenders in our climate for this brown-tipped
    disposition (STL, MO, zone 6b/7a). ‘Martinette’, the most prone, often
    emerges in late August or early September, and really begins pushing
    growth by December; ‘Avalanche’ emerges in October and doesn’t stop
    until it freezes to the ground or flowers and goes dormant. Other
    plants such as Geranium sanguineum, Nigella damacena, and Mertensia
    virginica are planted among these daffodils to help conceal their mostly
    yellow and brown foliage come flowering time.

    All good advice from Sir Frank, nonetheless… I will add this note to
    my ongoing cultural file. This is why I love Daffnet—we all learn so
    much from so many different, tried and experienced perspectives.


    Jason A. Delaney | North Gardens Supervisor and Bulb Collections
    Specialist | Department of Horticulture | Missouri
    Botanical Garden

    Post Office Box 299 63166-0299 | 4344 Shaw Boulevard 63110
    | Saint Louis | Missouri | United States of America

    Telephone (011 + 1) 314.577.0234 ext. 7 | Facsimile (011 + 1)
    314.577.9465 | http://www.mobot.org http://www.mobot.org

  8. Jason Delaney, Missouri Jason Delaney says:

    Peter, attached are some images of mosaic in the flowers. ‘Lavalier’ is faint, but you can see it in both the petals and even in the corona (darker striations). The other two images—of the same flower, posted to Daffnet some time ago—are a bit more obvious! J

    Yes, this mosaic pattern may “go away” over time, but that simply means the plant has grown stronger and can mask the virus’ presence; the virus is still very much alive in the plant as there are no cures for viruses. Apply stress to that healthy-looking plant and once more the mottling will reappear. Daffodil viruses are much like HIV in humans—with a healthy lifestyle and the right treatments, it can be largely overcome and in testing it can become nearly undetectable, even though the subject is still infected. To the naked eye, the visual symptoms of NYSV and mosaic are largely unseen in a well-grown plant; still, if it is known to be virused, despite how healthy it may grow and appear, caution should always be exercised when handling and distributing the plants.

    All Best,



  9. David Adams says:

    Jason, you wonderful man. Tomorrow, Friday, I am due to speak to a Garden Club on daffodil culture. As we have neither flowers nor foliage at this time of the year I have printed and laminated your photo to use as an illustration for the talk. It has come up really well.

    I hope you are happy for me to do this. Thankyou for a great visual aid.

    David Adams

  10. John Beck says:

    Thank you Jason,
    I appreciate you sharing your thoughts on virus.
    My understanding was that though tissue culture the virus can be removed
    but that the stocks this was done with were quickly reinfected in the
    growers fields.