Yucca Removal

Yucca, Yucca filamentosa, has slowly been encroaching on one of my prairie areas.  Yucca filamentosa is a North American native plant originally confined to the south-eastern portion of the United States.  It is considered to be a naturalized species in Ohio, with populations generally spreading from sites of human habitation where Yucca was planted for such uses as food, medicine or ornamental purposes.  Since I manage for native populations, the Yucca, non-native in my area, has always been on my list of plants to eradicate, but there have always been more serious matters for me to deal with.  A few years ago I began to notice new Yucca populations popping up hundreds of feet from the original infestation.  That discovery caused me to move Yucca removal to a higher level on my priority list.  After a couple of years testing treatment methods, I began in March 2020 to eliminate Yucca from Blue Jay Barrens on a large scale.

The long pointed leaves have fibrous strands that give the plant a rather worn look.  These are the filaments from which its scientific name derives.  The leaf edges can sometimes be abrasive and the leaf tips are often sharp.  I got plenty of scrapes and pinpoint wounds while dealing with this plant.

The vertical stem is generally quite short, but can sometimes reach up to a foot in height.  The leaves grow in a whorl from the stem with new growth coming from the tip.  The old leaves die to form a thick mulch that eliminates any competing plants from growing near the Yucca.

Here is the point of original infestation.  This open hilltop allowed for seeds to easily spread down hill.

I thought the origin site to be an excellent beginning point for Yucca eradication.  Especially since I have a well used walking trail running along the edge of this area and I was tired of seeing Yucca every time I went by.

From the top of the hill, Yucca spread down the slope to the west.

With this area cleared, I really had to stretch my neck to see any Yucca from the trail.

Yucca spread out near the base of the hill.  All cut Yucca plants were moved to a brush pile seen just to the right of the center of this photo.

At this point, all Yucca plants in the prairie area have been removed.  Those plants showing on the right side of the photo were removed the day after this picture was taken.

 As I cut off the Yucca plants, I piled the tops for future collection.

Cut plants were loaded onto a tarp and dragged out of the field.  Fortunately it was a down hill drag to the brush pile.

This pile, roughly six feet high and twelve feet wide, was made of plants cut from about one acre of prairie.  The pile will quickly shrink in size as the plants decompose.

Deer will generally not browse Yucca plants.  However, they seem to very much like the stems and treat the brush pile as a huge feeding station.  Individual plants are pulled out of the pile by the deer. They dine on the normally unreachable stem and leave the tops strewn about, sometimes a long distance from the pile.  Cut Yucca plants will easily root and continue growing if left on the ground, so I have to periodically gather up the tops and replace them on the brush pile.

I’ve removed Yucca from about one and a half acres of open prairie.  I still have about a half acre of Yucca growing in a shaded drainage area.  Other priorities have temporarily taken me away from this work, but I hope to continue the Yucca removal job later in the summer.  At a minimum, I will cut the flower stalks to eliminate seed production for this year.

A clump of mature Yucca plants appears to be a formidable adversary, but pushing aside the lower leaves reveals a soft underbelly.  Although the stems may reach a diameter of two inches, they are very soft.  I had no trouble slicing the stem with a pair of standard hand pruners, often severing the stem by simply pushing the pruner blade on through.

Removing the cut plant reveals the severed stems surrounded by a dead zone resulting from shading by the Yucca leaves.  In some of the larger clumps, lateral stems were poised to add to the size of the colony.  All parts of the stem in contact with the ground produce roots, so each new stem could become a standalone plant.  The roots are reddish in color and can be seen near the cut stems.

After cutting, I applied concentrated glyphosate, typically a 41% solution, to each cut stem.  Not knowing if the glyphosate would effectively eliminate the developing stems, I cut the tip from each young stem and treated it with glyphosate.  In my earlier trials, this method proved to be nearly 100% effective in killing the entire plant.

I treated a wide range of plant sizes.  Large plants were the easiest to find, cut and treat.  Smaller sized plants, such as that shown just below the large cut stem in the photo, were harder to locate.

Over the next few years I’m sure to be dealing with many small plants that evaded my search, but I’m sure the days of a widespread Yucca invasion are over.