Sep 11, 2018

The Effects of Glyphosate on Bamboo

The Effects of Glyphosate on Bamboo

vive la difference (?)

Let me start by saying I am not a fan of using synthetic compounds to control either animals, plants, or insects, but out of necessity I have occasionally resorted to what I consider the judicial use of a glyphosate (Roundup) on certain persistent and unwanted plants, namely certain bamboo species - the runners. When painted full strength on freshly cut culms the bamboo will usually die, or at least that portion directly connected to the point of application, within a week or two.

Now to something I find interesting.

Many years ago I was given a pot of Phyllostachys nuda by a friend. I divided the pot and proudly established two luxurious groves. Twenty years later their culms were rising ten to fifteen feet away from the mother plant, and the network of rhizomes they left in their wake was/is astonishing. Digging, even with mechanical aid was ultimately futile so I resorted to the use of Roundup. It worked, though every year I still have to stifle occasional new growth to keep it within bounds.

Now let me change direction momentarily.

About five years ago I noticed two beautiful twenty foot canes with very short, dense leaves towering above one of the nuda groves. I thought perhaps I was in possession of a new cultivar, a rare ’sport’ that would make me famous and rich. I thought that if I could only propagate these particular canes I could make a fortune, pay off my student loan, and move to the south of France. Of course I did nothing except admire them, and wonder how they had developed.

Move ahead a year or two

and I am strolling through the Los Angeles County arboretum when I suddenly see ahead of me a line of bamboo exactly like those that had appeared in my grove. I studied them for some time, allowing what little gray matter I have left, to analyze and perhaps deduce a connection, if one existed. Slowly it dawned on me as I connected the dots. This bamboo was adjacent to an asphalt pathway, though separated from it by several feet of barren ground, and I quickly realized that to prevent the bamboo from spreading into the pathway they were most likely using a powerful herbicide to keep the running bamboo in check - likely ‘Roundup’ or Glyphosate equivalent.

Back to the present.

I have a grove of Phyllostachys Atrovaginata, the incense bamboo, and it too has proven to be a ‘thug’. I keep it in bounds by painting ‘Roundup’ full strength on the new culms (after they have been harvested), and if the rhizome is not completely killed it seems the surviving canes produce vegetation not unlike that of Acer palmatum 'Shishigashira' the Lion's Head Japanese Maple.

Normal growth


Under the Influence


I wonder, if one could determine the correct amount, the precise concentration necessary, and the frequency of application to produce this genetic aberration, without killing the plant, I can envision only a profitable future, or at least a learned paper on the mechanisms involved leading to some esoteric advanced degree in horticultural science.


Respecting the Balance

Respecting the Balance


My wife found this caterpillar on one of the garden paths yesterday and it reminded me of why I do my best not to destroy the nests of hornets, yellow-jackets, wasps, etc. unless they are located in a ‘high-traffic’ area, like under the top of a picnic table around knee level, or beside the back door, I leave them alone. I am rarely stung, though my last encounter, two years ago, with a well-developed nest of bald-faced hornets who had built a sizable nest in a rhododendron I had decided to prune, almost made me change my mind. All in all members of the order Hymenoptera are extremely beneficial as predators against other insects, many of which do considerable damage to our vegetables and ornamental plants . This caterpillar, which I first thought to be the larval stage of the Luna moth, better known as a tomato hornworm (several tomatoes plants are nearby) is on reflection more likely that of Antheraea polyphemus, the Polyphemus moth. [What markings are visible seem wrong, and the shade of green too light.] All our tomato plants proved to be caterpillar free. Or is it perhaps the larva of a five-spotted Hawk moth, Manduca quinquemaculata

Regardless, the hornet(?), left side of the pictures, seems to have things under control.

Postscript


I went out this morning to make a detailed study and found the entire caterpillar gone!