Expert: Long Island Gardener - 2/1/2007

Question
Many of flower stalks that came up on my new amaryllis bulbs are not growing straight but curved.  These flower stalks have a single bumpy red line along the length of the stalk.  Some of the leaves on other bulbs also have leaves that curve to the side in a similar fashion.  I was told that it was fire but to me it is more charactaristic of a virus than a fungus.  I've never seen pictures of this phenomenon.  Does any of this sound familiar?  I'd like to know for sure what the cause is and whether it spreads from plant to plant.

Answer
Fire Blotch, Red Spot, Scorch, Red Blotch... Read all about it at the Oregon State Extension website (http://plant-disease.ippc.orst.edu/disease.cfm?RecordID=31) page on "Leaf Scorch" disease affecting in Amaryllis Belladonna.  This is a parasitic Fungus, Reva, which is better than a Virus because there is no cure in the plant world for Viruses and both of these spread.

We see very little of this in my part of the country, the Northeast.  But I hear frequently from gardeners down South whose Amaryllis show symptoms just like yours: oval or elliptical or irregularly shaped red spots, 1/4 inch to 1/2 inch long.   They appear up and down the stalks, flowers facing in cockeyed directions, all of this independent of where the window is or where the light is coming from.  Botanists call this fungus Stagnospora curtisii.

Authorities at Penn State Cooperative Extension (www.cas.psu.edu/docs/CASDEPT/PLANT/EXTENSION/PLANT_DISEASE/narciss.html) recommend a finger-cooking Hot Water Bath for all your sick Amaryllis bulbs.  Since this illness is contagious, you're better off cooking all of them.

Official Symptoms as posted by Penn State: "Reddish-brown spots with yellow halos develop on leaf tips as they emerge."  Eventually, spots "enlarge, merge together, and the leaves die.  Spots have small brown dots (fruiting structures) within them."  Those "fruiting structures" are spores with the potential to infect the entire bulb population of your county.  The sooner you rid yourself of them, the sooner the world will again be safe.

Red Splotch disease spreads via thrips, mites and even on your hands.  Badly infected bulbs should be destroyed.

If you want to investigate this further, as well as study some of the most beautiful photos ever taken of these flowers, have a look at photographer Starr Ockenga's "Amaryllis".  Ockenga has produced the definitive volume on these plants.  There ought to be one on the coffee table of anyone with a dozen of these; used copies are available from Amazon.com for around $5 and up.

Ockenga's text includes material on all kinds of diseases as well as exquisite photographs.

Specialists also use another reference, "Hippeastrum: The Gardener's Amaryllis" by Veronica Read, which includes chapters on diseases, breeding, and the ultimate guide to growing the most dazzling Amaryllis money can buy.  No longer will you be restricted to what you can pick up at Smith & Hawkin and bulb suppliers.  This is newer and sells for around $35 at Amazon.com.

I presume your phrase "I was told that it was fire" is actually intended as "I was told that it was fungus".  Si?

Let's discuss the bath.

A hot water bath is one of those harmless-t-everything treatments that destroys all kinds of bad things in the garden and greenhouse.  Daffodil growers use them to cure their bulbs of the nasty little Narcissus Bulb Fly, which incidentally will also attack Amaryllis bulbs. Each bulb is dipped for exactly 40 minutes in water heated to 110 degrees C for 40 minutes, then quickly removed to minimize heat damage to the bulb.

Some growers immediately dip treated bulbs in Sulphur, Thiabendazole or Thiophanate Methyl, which are fungicides.  I prefer Sulphur because it is the most organic thing you can get your hands on.

Once dried, the bulbs can be replanted but should be monitored to make sure they are no longer infected..

There are other causes of reddish specks and streaks on Amaryllis plants.  Simply injuring a bulb will sometimes show up as a red splotch.  Spider mites can do it, too.  But this is the most common one.  And believe me, this is common.

The virus you were probably wondering about is "Mosaic" virus.  This would have different symptoms: yellow and green streaks on leaves and stems plus severely distorted flowers.  But as I said before, there is no treatment ... yet.

Let me know if you have any other questions.  Thanks for writing, Reva!