Tulip Viruses

During the 17th century the Netherlands were taken over by what is called "Tulip mania." Shortly after being introduced tulips became a symbol of status and a way to showcase wealth publicly. Semper Augustus, with its red and white streaked petals, is famously remembered as being the most expensive tulip sold during the "Tulip mania." At the time it wasn't known that the spectacular colors in the petals of tulips were caused by a tulip virus. Tulip breaking virus was carried by the green peach aphid and while the virus caused beautiful flowers, it also caused weak bulbs that died slowly. Anna Pavord, author of Bulb, tells us of similar speculative bubble happening in England with snowdrops today. Not quite to the extent of "Tulip mania" but it is interesting to see that we're all more than happy to repeat the mistakes of the past.

Not Semper Augustus but a tulip in my own garden with red and white streaks. Going out into the garden to survey the three blooms of this tulip (NOID) helps me to understand how something like 'Tulip mania' could've occurred, the blooms are beautiful. Earlier this spring as the bulbs were emerging in the garden from the window I noticed that something was different with the tulip bulbs in my garden.

From a distance I could see that the leaves emerging from some of the tulip bulbs were stunted and contorted.  Here is a photo of a tulip bulb leaf showing signs of a virus next to a healthy tulip leaf from a bulb growing right next to it.

We've had a pretty dry spring this year and for a moment thought that perhaps the leaves were growing in this weird fashion because the bulbs had been dry as they were breaking dormancy. The plants in my garden have to survive on mostly rain water because I use as little water as possible to maintain them. Not exactly a rain garden but plants that aren't very tolerant of drought find themselves quickly ignored and die. The tulips have done surprisingly well the past couple of years that I've instituted the restrictive watering practice. The second clue that what my garden bulbs were experiencing wasn't normal was the streaks in the leaves. The photo above shows a streaked tulip leaf next to a healthy tulip leaf growing in the same clump of tulips.

Here is a photo of the clump of tulips in my garden showing some normal tulips and some diseased tulips growing next to each other. Can you see the difference in the leaves?

On the right in this picture is a pink tulip that looks the same as they have in recent years. On the left is a bloom from one of the infected tulips, it used to look like the tulip on the right. The changed blooms is the final clue, the weird growing habits and leaves aren't related to the garden being kept dry to conserve water. This clump of tulips in my garden is infected with some kind of virus.

Tulip viruses
Tulip breaking virus (TBV)

Arabis mosaic virus (ArMV)
Tobacco rattle virus (TRV)
Lily symptomless virus (LSV)
Tobacco necrosis virus (TNV)
Cucumber mosaic virus (CMV)

Symptoms of tulip viruses
‘Breaks’ (streaks of a different colour) in the flowers (TBV).

Brown, dead streaks appear in the leaves and stems (TNV).
Mottled leaves (TRV, LSV).
Sunken brown spots, arcs or rings in the bulbs, such bulbs give rise to stunted and distorted plants (CMV).
Plants may be stunted, but not otherwise unaffected (ArMV, LSV).

While searching Google for Gardeners for clues as to what was affecting the tulip bulbs I came across this list of tulip viruses on the RHS website.

How tulip viruses are Transmitted
Vectors for these viruses include aphids and nematodes that that live in the soil and some are vectored by other insects or transmitted on prunning tools. There is no cure for tulips that have viruses and once found infected tulips should be destroyed to prevent spreading.

Purchasing tulips from reputable sources, both mailorder and retail, will help lessen the chances that you buy infected bulbs. When I purchased my bulbs they were healthy, free of blemishes and the skins were intact. This leads me to believe that the vector in the case of my tulips was one that was inhabiting the soil. My only option here is to remove and destroy this clump of tulips and start over and attempt to do something about any possible nematodes inhabiting the garden before this spreads to other bulbs, mainly my black tulips "Queen of Night" and "Black Parrot".