2018 Teasel Pulling Results

My Teasel removal activities took so little time this year that I can’t even describe the activity as an event.  I spent about four hours walking fields with a history of Teasel infestation and pulled all of the Teasel plants I found.  A total of about 12 acres was searched.

This is my second year of pulling Teasel plants.  Prior to that I collected ripe seed heads on an annual basis.  Last year’s effort occurred about a week prior to expected seed ripening.  This year I began pulling when most plants were just beginning to bloom.  Teasel plants stood above most other plants in the field and were easy to see.  The Teasels were widely distributed across the field as individual plants.  No clusters of plants were found.

This is last year’s harvest of Teasel plants.

This is what I collected this year from the same area, a significant reduction.  There are always a few plants that show up late in the season because they were slow to begin growth or are recovering from injury.  I’ll walk the fields again in the next week or two to search for those late developing plants, but I doubt if I’ll find many.

Pulling is now my preferred method of dealing with Teasel plants.  I can begin pulling when field vegetation is relatively short, so it’s easier to move around and find the plants.  Pulling the plant takes much less time than removing all of the seed heads.  Pulling before seeds are ripe eliminates the chance of spreading seed to other parts of the field.  I think I’ve reached the point where annual Teasel control is going to take very little of my time.  It’s nice to see the fields devoid of invasive Teasel plants.

Pulling Teasel

In an effort to eliminate invasive Teasel from my fields, I have taken time each summer during the past several years to remove the ripe seed heads from the Teasel plant.  Results have been positive.  The Teasel population is notably diminished over what it was just three years ago.  Instead of large Teasel patches, I now just have individual plants scattered around the field.  The problem with this control method is that the timing for Teasel seed head removal is critical.  Ideally, the activity should begin when the most mature seed heads are just a couple of days away from dropping their seed.  Beginning too late allows mature Teasel seeds to be lost during the collection process, giving rise to another crop of mature plants in two years.  Beginning too early allows for the possibility that the plants will produce new flowers that will mature before the end of the season and scatter new seed in the field. 

I was determining the progress of Teasel seed production and found most plants to be about a week away from releasing mature seed.  As I looked at the plants, I began to wonder how easily a Teasel plant would pull from the ground.  If I pulled the plant, I would not have to worry about it producing any new flowers.  Pulling would also allow me to begin work earlier in the year and increase my collection window from a few days to a few weeks.  I figured that pulling was worth a try, so I headed for the barn for a pair of heavy work gloves, an absolute necessity if you are going to grapple with a spiny Teasel stalk.

Despite its impressive root system, Teasel turned out to be fairly easy to pull.  There were a few that held tight, so I cut these off at ground level.  I’m betting that the root system won’t be able to produce a new mature plant before cold weather sets in.

The work of plant pulling went much more rapidly than seed head collection ever did and piles of Teasel plants began to accumulate on the trail between two fields.  I spent eight hours at the task and searched an area of about 12 acres.  Only about five of those acres actually yielded any Teasel plants.  I just wanted to make sure there weren’t any infestations that I had not yet discovered.

I learned one trick that came in handy, especially in the tall grass areas.  I left one tall Teasel standing in the area that I worked and piled pulled plants at its base.  I then moved on to the next section and did the same thing.  The standing plant allowed me to easily find my cut pile when I was ready to haul the plants out of the field.

This group of ten plants represented a new infestation.  Just beyond the trees in the background is the township road.  A culvert crosses the road at this point and dumps runoff water into the field.  Along with the trash and debris from the road are often a few weed seeds.

All of the collected plants were consolidated into a single pile.  The pile is located at the field edge next to my vegetable garden and is used as a depository for any noxious plants that may drop viable seed.  I pass this pile several times a week and will destroy any undesirable plants that try to grow here.

Even the most developed seed was not near maturity.  The seed shown here has shriveled considerably since the plant was pulled two days ago and may not be viable.

Several of the plants had played host to some type of stem borer.  The borer doesn’t seem capable of killing the plant before seed matures, so it is not likely to be valuable as a control method.

Tiger Swallowtail butterflies were especially numerous in the field.  I scared dozens from the Teasel as I worked.  Fortunately, there are plenty of native wildflowers that the butterflies like just as well.  Pulling Teasel and removing the entire plant turned out to be much quicker and easier than collecting seed heads.  I’ll definitely continue this practice in the future.  At least until I run out of Teasel.

Invasive Control - Misc Forbs

In many instances, the simple task of hand pulling is the most effective way of eliminating unwanted plants.  This pile of invasive Sweet Clover, Wild Carrot and Oxeye Daisy was removed from a one acre barrens opening this past summer.  Remnants of last year’s plant collection can be seen beneath this year’s greenery.

This area is typical of the Blue Jay Barrens openings.  Steep, shallow, extremely dry soils present numerous challenges to plant growth.  Invasive plants can become established, but not with the ease or rapidity demonstrated in the former cropland areas.

The welcome mat for invasive plants is in the form of exposed soil, a defining quality of barrens sites.  A seedling that overcomes the other obstacles can grow undisturbed by competing vegetation.  Colonization may be slow, but a persistent species can build quite a population over a period of years.

This is my fourth year of pulling Sweet Clover and Wild Carrot from this site.  Plant removal is quite an effective control method for these species.  They are biennials that form a rosette in year one, then produce seed and die in year two.  If you can halt the production of seed, you can eliminate new generations of plants.  An annual maintenance visit to each site is still necessary to catch any new plants that may emerge.  Sites that I began treating 10+ years ago, now have only a few Sweet Clover plants per acre and virtually no Wild Carrot.  Sweet Clover seed is notorious for persisting in the soil seed bank and remaining viable for decades after falling from the plant.  In order for the seeds to survive for that length of time, they need to be incorporated within the soil profile where they are protected by the ravages of weather and other environmental factors.  I’ve noticed that most of the studies of Sweet Clover seed longevity have been completed on former crop ground, where fresh clover seed could have been neatly buried by common agricultural tillage practices.  Seed produced on the barrens is unlikely to get buried to a depth that would allow it to be protected for extended periods of time.  The seed here stays near the surface and either germinates or dies, so removing plants rapidly produces positive results.

I’ve also been getting more hands-on with the invasive Oxeye Daisy.

I’m still looking for an effective control method in the old crop fields.  The plant is too numerous and too crowded by prairie plants to be easily removed by hand.  There are also too many quality native plants here to make herbicides a viable control alternative.

This Ragged Fringed Orchid, Habenaria lacera, visible in the center or the preceding photo, is just one of many unassuming plants that has found itself being pressured by Oxeye Daisy.

Oxeye Daisy has been slowly making its way into the barrens.  I hand pulled the daisy from a few test areas two years ago, with favorable results.  This year I pulled Oxeye Daisy right along with the clover and carrot.  New daisy plants begin as a basal rosette.  When they’ve stored enough energy, they send up a flower stalk.

Oxeye Daisy removal is totally effective if you leave no viable plant parts in the soil.  This young plant pulled easily and shows no evidence of missing underground parts.

A slightly older plant displays the start of a rhizome that would eventually give rise to new plants.  The stub of a broken rhizome on a pulled plant means that a viable plant part has been left behind to grow a new plant next year.

A single plant will eventually produce a thick colony of plants.  This plant has a single tall flower stalk and three healthy rhizomes.  I think I’ll be able to successfully eliminate Oxeye Daisy from the more rugged barren sites, but I’m still looking for viable control options in other areas.

I’m still collecting seed heads from Teasel in early August, but I also now treat random plants while I’m out doing other invasive species work.  A shot of glyphosate into the center of a basal rosette will kill the plant, or at least damage it enough that it never produces a flower.  Tall plants can be cut and the stump given a little spray of glyphosate.  These two methods would be difficult to apply on a large scale, but are handy to use when finding a handful of plants in an isolated location.  It’s easier to eliminate the plant at the time it is found, than it is to remember to revisit that spot later on to collect seed heads.

Of course, I’m always interested in animals that feed on invasive plants.  I found this stalk borer inside the base of a tall Teasel plant.  I doubt the borer would have killed the plant, but similar borers might be the reason I occasionally find plants broken off at the base.  These broken plants may lay down and hide in the tall grass, but the flower stalks turn upward and still produce plenty of seeds.  Since I have trouble finding these fallen plants, the borer may actually be hindering my control efforts.  Despite minor setbacks, I’m sure that I can eventually get most of these invasive plants under control.

2015 Teasel Seed Head Collection

I have completed collecting Teasel seed heads for the 2015 season and am happy about the progress being made in reducing the number of Teasel growing in the fields.  Gathering the seed heads prevents the ripe seed from being scattered about the field and producing a new generation of this non-native invasive plant.

This is the third consecutive year that I have gathered Teasel tops from the seven acres of Teasel infested young prairie at Blue Jay Barrens.  This area, formerly the site of a moderate Teasel infestation, was practically Teasel free this year.

Most of the Teasel was scattered across the field as individual plants or small groups of two or three.  Areas of concentrated Teasel were generally less than 20 feet in diameter.

Unusual this year were the random plants that appeared to have lost their tops to browsing deer.

These topped plants managed to send up new shoots that flowered and produced seed heads.  The deer are going to have to do better than this if they wish to be heralded as a new weapon against Teasel.

My entire 2015 collection fit into three feed sacks, none of which was filled.  Total weight collected this year was 36 pounds, a 63 percent reduction over last year’s 97.5 pounds.  Teasel has a two year life cycle.  Year one is spent as a basal rosette of leaves.  During its second year, the plant sends up a tall stalk and produces flowers.  The plant then dies and the seeds are dropped as the plant dries.  The reduction in population size this year is a result of the 2013 seed crop being removed from the field.  The Teasel population size should continue to shrink, but the seeds previously dropped in the field can wait several years before germinating, so it will be a while before the population is reduced to a negligible amount.

I’ve had a lot going on the past couple of weeks, so the only time I could put to collecting Teasel was early in the morning.  Awaiting me each morning were a few Teasel heads, dew laden Indian Grass and a large collection of spider webs.

The webs were the product of the Banded Garden Spider, a common resident of this field.

Each orb web was accompanied by a structure of random webs to one side.  The spider was sandwiched between these two creations.  I assume the intent of the random webbing is to give the spider notice of the approach of a possible predator, such as a spider hunting wasp.

I left one late flowering Teasel head in place for a couple of days to give this Red-Banded Crab Spider a chance to finish its meal of Robber Fly.  That big fly should be more than enough to fill up the spider.

The buzz of Robber Flies was common throughout the field.  Diogmites species like this were especially abundant.

A first for me at Blue Jay Barrens was the sighting of this Citrine Forktail.  This tiny damselfly would be nearly impossible to find if you were searching for it.  I saw it only because the low angle of the sun made the insect appear as a bright fleck of gold among the sea of Indian Grass.  I don’t know what it was doing out in the middle of a dry prairie so far from water, but I’m glad it was there.

Teasel Topping Completed

The 2014 Teasel seed head collection filled six feed sacks.  I stomped the seed heads together with my boot as they were dumped into the sacks, so each sack is tightly packed.  This collection was made from an eight acre area of old crop fields that represents the extent of Teasel infestation at Blue Jay Barrens.  Time spent collecting was just over 16 hours spread over five days. 

This two acre field directly behind the house was part of the collection area.  Even though I know that Teasel still persists in the field, I’m not constantly reminded of the fact by the sight of Teasel seed heads standing tall above the other plants.  I learned long ago that work in areas that I see most often should be placed as top priority. 

I took a few minutes to walk around and enjoy the view of late summer fields without visible Teasel.

While dealing with this batch of Teasel at the base of an active ant mound, I found myself acting out the classic ants-in-pants comedy routine.  I must have been standing on one of their foraging trails, because it only took a few seconds for a dozen or more ants to crawl up inside my pants leg.  Allegheny Mound Ants have powerful jaws that can slice into the flesh, but it takes time for them to accomplish that feat.  To make their initial attack more effective, the ants curl their bodies and apply a bit of formic acid to the wound they are making.  The acid isn’t felt on bare skin, but causes a quick burn to even a minor cut.  I’m sure my little bout of stomping, scratching and pants slapping would have amused even the most somber audience.

It’s easy to locate the tall Teasel.  The trouble is finding short growing Teasel hidden by the taller vegetation.  I collected many seed heads from plants that were not much taller than 12 inches.  I’m sure many of these short plants were missed and their seeds will likely reach maturity.  While working, I had visions of a future where my fields were infested with dwarf Teasel, descendents of the short Teasel that avoided my annual collection.

My efforts yielded a total of 97.5 pounds of seed heads.  After weighing a random sample, I estimated there to be 108 seed heads per pound.  That means a total collection of 10,530 seed heads.  At an average 3.5 seed heads per plant, the total Teasel population was just over 3,000 plants.

Examination of several seed heads provided me with an estimated 725 seeds being produced per seed head.  My seed head collection efforts resulted in more than 7.6 million seeds that have been denied the opportunity to produce new plants at Blue Jay Barrens.

On my last day of collection, a thick fog persisted into late morning.  Many flying insects were grounded as they awaited their wings and bodies to dry enough for flight.  This makes it easy for a photographer to approach these normally wary creatures.

This Peck’s Skipper has its wings spread and is waiting for the sun to penetrate the haze and dry things off. 

Skippers have a neat little hooked tip at the end of the antenna club that sets them apart from butterflies.  The dew has this little fellow looking a bit ragged.  I must admit that I looked in much worse shape than the skipper.  The temperature was near 90 degrees, the air was perfectly still and the humidity level had to be over 80 percent.  The combination of dew and sweat had managed to get me completely soaked and I had Indian Grass anthers stuck all over my face and arms.  Fortunately, I always keep the camera pointed away from myself.

I discovered many Monarch caterpillars as I traveled the fields searching for Teasel.  Most were on Butterfly Weed where they concentrated on devouring the flowers.

Teasel seed left on the ground can remain viable for as long as five years.  I’m sure I’ll see a reduction in the number of Teasel plants before that time, but I’ll have to be vigilant in my seed head removal efforts for several more years before I can feel confident that any sections of the field have been rendered teasel free.