This is a public-interest archive. Personal data is pseudonymized and retained under GDPR Article 89.

Re: weeds


I think Carl's message (Sun, 27 Jun) is the first I've seen on this topic
that mentions something as important (and maybe more important) as
burning/spraying, and that is good species diversity. We all know that
good management is very important, but I think people should consider the
other half of the equation: competition from a diversity of native plants.

We use our knowledge of the weeds to manage them.  For example, if weed is 
intolerant of burning we burn it.  Cool season weeds are controlled
by burning in the cool season, and woody weeds are controlled by burning 
in the fall.  Some weeds can be mowed or "deadheaded" just when they 
are flowering, and many are very intolerant to grazing at this time, so
we graze them at this time. These approaches all make perfect sense and
usually work very well, but I think we can make better use of our
knowledge of the weed's growth habits.

In the same way we use a weed's weakness against them in our management,
maybe we should make use of these weaknesses in our species selections.
By introducing native plants that will effectively compete for limited
resources like water, light, and space we've introduced a constant
pressure on the weeds. For example, we should seed in shallow rooted
natives to control shallow rooted weeds, or we could use taller natives to
shade out shade-intolerant weeds, or use natives that produce a lot of
litter to control weeds that require bare soil to germinate. I think
techniques like these would complement the use of other management very
well.

After spending many worthless hours pulling and spraying Burdock in a
reconstruction, I've decided to seed and plant native pioneer species and
let the disturbed area "heal" naturally.  I'm seeding and planting Canada
Goldenrod, Common Evening Primrose, Yellow Coneflower, and Tall Coreopsis.
Spraying and pulling left a vacuum that was always re-filled by the same
burdock, but planting native pioneer species does the opposite by
introducing competition. Goldenrod and Evening Primrose compete for light
(they grow taller and faster), the Yellow Coneflower competes for
water (similar root depth), and the Coreopsis should do both.  Although
not useful in all cases, this approach could be used in other
circumstances.

These thoughts may seem obvious to some, but I think they are worth
restating.  Tell me what you think.

Chris Hauser.

On Sun, 27 Jun 1999, Carl Kurtz wrote:

>Crown vetch here in central Iowa the most difficult plant to eradicate from
>a prairie, because of its growth form.  I have been fighting it for the past
>7 or 8 years in one area that adjoins a roadside which I have sprayed out
>continually, and it is still popping up each year from old seed.  When we
>burned the roadside last year, it scarified thousands of seeds and new
>plants came up everywhere, and there had not been a flowering plant on that
>slope for more than 5 years.  
>
>Sweet clover can be removed by late season fire in successive years and
>hand-pulling.  It still shows up in old plantings, but the incidence of it
>gradually decreases each season.  
>
>Canada Thistles will be eliminated by competition for rootspace and good
>species diversity in 5 or 6 years.  Our plantings more than 8 years of age
>have no Canada thistles.  We still, however, pull them in new
>reconstruction's when they are in the bloom stage.  
>
>Red clover also appears to decrease as the planting ages and root space
>fills up.  We dig red clover, but where it is a serious problem, we are
>spraying it with Round-up in early November to kill the mature plants.  This
>also scarifies old seed so you need to follow up on the procedure in
>successive seasons.  
>
>Curly dock plants will decrease in size each season and nearly disappear by
>the 5th or 6 growing season.  You do need good species diversity to combat
>it, however.  We also dig curly dock which really helps reduce the problem. 
>
>
>Alfalfa in a good planting may live a very long time.  We still have plants
>in one 9 year-old site, and I believe they are the same plants.  It is
>nearly impossible to dig out, but easy to wick with Round-up.  Don't plant
>in an old alfalfa field until you have planted it to corn or soybeans for a
>couple of years.  
>
>Smooth Brome is of little consequence in a good diverse planting.  Where is
>is a problem consider spraying with Post (a grass herbicide for soybeans
>about the 1st of May) after a spring burn. Late spring burns also tend to
>set back brome as well as other cool season grasses.  
>
>Reed canary grass is a serious pest in most wet-mesic sites in our area. 
>Good species diversity helps.  We also wick it with a 30% Round-up solution
>just before flowering and get very good control.  You can also try Post
>after spring green-up.  Fall applications of Roundup when other plants have
>stoped growing can also be very effective, however, reed canary grass needs
>to be mowed in September to remain green until freezing weather.   
>
>Annual weeds which are disturbance oriented all seem to disappear rather
>quickly and are really good at holding the soil in new plantings.  I just
>consider them a nurse-crop and keep them mowed during the first year after
>planting.  
>
>One plant not  on this list is bird's foot trefoil, which is nearly
>impossible to eradicate from a planting once it is introduced.  I don't
>think it is quite as bad as crown vetch, but I am making a serious effort to
>eliminate is from adjoining roadsides in our area.  And it is not an early
>task.  
>
>Carl Kurtz
>
>----------
>>From: MJ Hatfield <oneota@ames.net>
>>To: Prairie L <prairie@mallorn.com>
>>Subject: weeds
>>Date: Fri, Jun 25, 1999, 7:39 AM
>>
>
>>I'd like to ask you folks who are working with restoration and
>>reconstruction of prairie to list the weeds in order of nastiness, and
>>explain why. And perhpas list your method of preferred control. Feel
>>free to add to the list.
>>
>>The reason I'm asking is that there is only so much time to work on weed
>>eradication and I'd like to know your thoughts as to where effort should
>>be placed.
>>
>>Thanks.
>>===============================
>>sweet clover
>>crownvetch
>>wild pasnips
>>Canadian thistle
>>Reed's canary grass
>>dock
>>Queen Anne's lace
>>bull thistle
>>red clover
>>brome
>>alfalfa
>>creeping charlie
>>dandylions
>>foxtail
>>mustards
>>
>>
>>---------------------------------------------------------------------
>>To sign-off this list, send email to majordomo@mallorn.com with the
>>message text UNSUBSCRIBE PRAIRIE
>---------------------------------------------------------------------
>To sign-off this list, send email to majordomo@mallorn.com with the
>message text UNSUBSCRIBE PRAIRIE
>



---------------------------------------------------------------------
To sign-off this list, send email to majordomo@mallorn.com with the
message text UNSUBSCRIBE PRAIRIE
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index