The Wonderful Water Plant

For an illustrated version, see page 16 in The EnvironMentor, Aug-Sep 2014, vol. 3 no. 1.

Tales from EarthTeller:  “It Seemed Like A Good Idea At the Time.”
FOLKTALE: The Wonderful Water Plant.
    A rich man built himself a mansion in the country, surrounded by beautiful landscaped gardens. Of course he needed an ornamental lake. And he asked his gardener to plant the lake with beautiful water plants.
    “I found something new, boss,” said the gardener. “It’s hardy, strong-growing, not bothered by insects or diseases, and it has gorgeous flowers!”
    “Sounds perfect,” said the rich man, “get some. It will look pretty with my swans.” So the gardener planted a patch of the new water plants at one side of the lake. 
    The new plants grew so well that every day they DOUBLED the area of the lake that they covered! The boss was delighted.
    However, by the end of the month, this water plant had completely covered the lake. There was no room for the swans. The rich man was furious.
 
    Here’s a question for you: If the lake was completely covered on the last day of the month, on what day was the lake only HALF covered?  (see below* for the answer)
 
 
FACT TALE: Kudzu  -- the plant that covered the South.
     Kudzu ((Pueraria lobata or P. montana) first came from its native Japan to the U.S. in 1876, at the Philadelphia Exposition where it was introduced as a beautiful landscaping vine and a quick source of shade. Its pretty purple flowers resemble wisteria. By the 1930’s, farmers were planting it for animal forage and erosion control. A legume, kudzu enriches the soil with nitrogen. Its deep roots bring up minerals.
    But kudzu grows so fast (up to 1 foot a day) that it can quickly swarm over trees, fences, buildings, even parked cars! Its big leaves block sunlight from the plants it covers, often killing them. Its vines grow through windows and pry under shingles. Now out of control in the deep south, kudzu has been found in Oklahoma as far north as Tulsa and Guthrie. An ecologist even found it in Canada, on the shores of Lake Erie!
    How to get rid of this “good idea that ran amok”? Dig up the roots--but be sure to get every piece, because even a tiny bit can regrow. Cut down the vines--but be careful to destroy the cuttings, because they can root and start new vines. (Some people warn that if your “grapevine wreath” from the deep south was made from kudzu rather than grape, if it gets wet it can take root even after hanging on the wall for years...) Now some towns let goats and llamas eat it: if they overgraze it for several years in a row, they do a better job even than fire or herbicides.
 
Kudzu! It seemed like a good idea at the time.
 
*If it’s doubling every day, and covered the whole lake on the last day of the month, that means that on the next-to-the-last day it had covered only half the lake. I’ll bet the boss thought he didn’t have a problem because his swans still had half the lake to swim in!