Feb 10, 2018

Was it Spaghetti or Dodder in the Ditch? 

By: Lawanda Jungwirth  

I thought somebody threw spaghetti in the ditch.  Again!  Actually I have found spaghetti in the ditch along our country road, among many other strange things.  I’m sure Badger Sportsman readers aren’t the ones bringing their broken TVs, couches, bags of salt, pumpkin pies, old tires, deep fryers, kittens, dogs and yard waste out to the country to dump them, but if it’s your friends doing this, tell them to quit it!  Anyway . . .  this time the spaghetti-looking thing in the ditch wasn’t spaghetti at all; it was a plant called dodder. 

Dodder is a parasitic annual plant that lives off other plants rather than doing its own photosynthesis work.  No, it takes the easy way out and finds a host plant from which it can suck the life.  It doesn’t even bother growing its own leaves!  I saw orange dodder, but other species may be white, yellow, pink or brown. 

Dodder is rather promiscuous in that it isn’t too choosy about its host plants.  The dodder I found was on jewelweed, but it can also be found on alfalfa, flax, clover, potatoes, tomatoes, eggplant, asparagus, sugar beets, chrysanthemum, dahlia, helenium, trumpet vine, ivy, petunias, carrots, cranberries, hops, beans, and some trees and shrubs.  It avoids grasses, so your lawn and prairie areas are safe.  It also sidesteps, corn, lettuce, cauliflower, broccoli, lilies, irises, orchids, wheat and soybeans. 

Here’s how dodder does it.  Soon after its seeds germinate, a slender, threadlike stem emerges and starts waving around in the air looking for a host plant.  It uses something called chemosensory cues, which are airborne chemical signals emitted by other plants, to decide in which direction to head.  The dodder only has five to ten days, in which time it grows to a foot tall, to find a suitable host or it will die.  As soon as it touches a satisfactory host, it begins twisting and twining itself around the unfortunate plant.  Then the dodder develops tiny root-like structures called haustoria that it inserts into the host’s vascular system from which it begins to extract water, nutrients and minerals.  Once the dodder’s got its claws into a host plant, the dodder’s root dies off and it lives entirely off the host. 

Dodder is an ectoparasite, which means it lives outside of its host rather than inside it like the tapeworm your dog might get.  That would be an endoparasite.  Well, never mind; you probably didn’t need to know that. 

Of course the poor host plant becomes debilitated.  Then it loses its ability to resist insect pests and diseases, so in those rush.  Once the original plant is all twisted up, the dodder reaches for another plant and another until it forms a dense intertwined mat.  As it reaches each new host plant, it spreads any diseases along.  You can see how this would be devastating in an agricultural setting.  The degree of damage depends upon the maturity of the host plant.  Seedling host plants would likely be killed, but more established plants will just lose vigor.  Of course, pests and diseases may then do them in. 

There are over 150 species of dodder worldwide, three of which do the most damage in the United States.  It doesn’t really matter which species I saw or which one is strangling your food plot; they’re all bad.   

Dodder does make the effort to produce little bell-shaped flowers in summer and they are rather pretty, ranging in color from white to yellow to pink.  Unfortunately, those flowers soon turn to tiny 1/16-inch seeds – up to three thousand per plant!  Only about 5% of those seeds will germinate the following spring, but the un-germinated ones can remain dormant and viable in the soil for up to 20 years depending on conditions. 

Dodder seeds spread through the movement of soil and equipment, on muddy shoes, paws and tires.  It can also be found as a contaminant in crop seed or hitch a ride on plant material.  Water can spread the seed if the dodder grows beside a lake, river or stream. 

What should you do if you find dodder on your property?  If it hasn’t yet begun twining around a host plant – and really it’s unlikely that you’ll see it at this stage, but anyway – just pull it from the soil.  If it has begun its chokehold, the host plant must be pruned well below the dodder and removed from the site in plastic trash bags.  This is especially important if the dodder isn’t discovered after it has set seed.  Any little piece of dodder left on the plant can continue to grow once it’s got its hooks into the host.   

Larger infestations can be mowed, pruned, burned or sprayed with herbicides.  One time won’t do it; the area will need to be monitored for many years – remember, the seeds are viable for decades.  It is best to plant non-host plants in the area for several years before switching back to possible host plants.  Even then, monitor the area closely and physically remove any dodder that grows before it attaches to the hosts. 

Chemical control isn’t usually needed in the home landscape and garden, but in an agricultural setting pre-emergent herbicides containing DCPA, dichlobenil, propyzamide, or trifluralin can help, followed by close mowing, burning, repeated tilling or spot removal of plants that didn’t succumb to the herbicide.  There is no post-emergent herbicide that will kill just the dodder – the host plant will also bite the dust.  In a bad infestation, this may be necessary. 

Always inspect and clean equipment and clothing when moving from a dodder infested area to clean areas.     

DODDER HAS MANY ALIASES!  

Other names for dodder are strangle tare, scaldweed, beggarweed, lady's laces, fireweed, wizard's net, devil's guts, devil's hair, devil's ringlet, devil’s shoelace,  goldthread, hailweed, hairweed, hellbine, bellbind, love vine, pull-down, strangleweed, angel hair and witch's hair.  

FOLK USES FOR DODDER 

  • Around the time of WWII, Native Americans, who called dodder “Devil’s Shoelace,” filled burlap sacks with crushed dodder and used them to whack fish to stun them. 
  • In the South, young women, who called dodder “Love Vine” would break off a piece of it and throw it on another plant while calling out the name of a young man.  If the dodder successfully took hold on the new plant, the affection was mutual.  (Wouldn’t plucking flower petals and saying “He loves me, he loves me not” have been a better idea than spreading dodder all over the place?)