Progress on the Lawn

Sandbur season is just starting (June) and will run through September.

We have been very aggressive at mechanical removal of sandburs.

Last year we dug up 29 5-gallon buckets of sandburs bay September.  We are currently at 1.5 buckets in the middle of June.

I started the season with a heavy dose of starter fertilizer to encourage germination of the sandburs.  This may sound strange, but I cannot kill them if they don't sprout. Besides, the lawn needs fertilizer BADLY.  So I plan on lifting it several times this year in preparation for the new lawn seeding in October.

The lawn is to the point we can reasonably pull sandburs in a couple of stages a week.  

I have started flagging sandburs with marking flags to see the patterns they germinate in.  This helps identify areas where they are originating from.  By doing this, I have found 4 hotspots that get special attention.

We walk the entire lawn before mowing and dig all sandburs we can possibly find, then I mow.  After mowing we walk it again.  The mowing exposes more sandburs.  

There are 3 different types of weeds commonly called sandburs.  

2 types put on seeds after getting taller (6" or so) and are easy to control by frequent mowing.  The idea is to prevent the weed form putting on seed at all.  The annual nature of the weed will eventually cause it to disappear from your lawn.

However, there is one species in Oklahoma that is particularly hard to control.  It puts on seeds at about 1" in height.

Our strategy is to mow regularly, but at the highest setting on the mower.  This has virtually eliminated the field burs form our lawn.  This also makes it easier to see the hard-to-get species.

The current state of the lawn is far better than it was a year ago.  A year ago sandburs and goat heads were easy to spot from any place you stood on the lawn.  Today, we only see signs of one species or sandbur.  The other two are found occasionally, but rarely and we have not seen a goat head since last year.  It is a bit early this year to be stating they are eradicated, though.

I am moving to a new stage in the battle.  I am able to identify the sandbur before they put on seed and I can remove them from the equation earlier.

The roots are very shallow, making the plant easy to pull out of the sandy soil it loves most.  Often times you can see the seed still attached to the root.

The plant itself is fan-shaped.

This is the same plant as above, just turned 90 degrees.

The base of the plant is often reddish purple.

Even when you find a round tuft of sandbur, it is often composed of several of these fans. 

This is what it looks like in the ground. The green color is between the light green of nutsedge and the green you see in Bermuda grass.  In early Summer, this green stands out fairly good.

We have altered the process a bit this year.  We have started flagging the stickers with seed heads with marker flags.  This makes hot spots stand out.  It also allows us to gauge how we are progressing. I suggest getting 100 flags per acre to start with.  Each 100 flags should be different colors.  This has allowed us to realize progress in an otherwise seemingly never-ending task.  Initially I was planting 200 flags per day.  That grew to 400 per day in a matter of 2 weeks.  We are currently sticking about 100 flags a day.  Even though it does not seem like it, we CAN measure progress.

I continue to mow in a square and blow all the clippings into the center.  This helps consolidate seeds into a smaller and smaller area.

I am also treating the area with Image for Nutsedge as it is supposed to kill small sandbur seedlings.  I have not decided if its working, but I had an abundance of nutsedge in the lawn, so it DID aid in that aspect.  So officially, Image for Nutsedge works good on various nutsedge species.  It is also pretty efficient for that weed as I only applied it at 24 oz/acre mixed at 0.75 oz/gallon.  It is probably the best Sege killer I have found.  We will see if it comes back next year, but as of today, it is all brown and crispy.

Other things I have learned about sandburs:  They go to seed extremely fast.  They can go from no seeds to dropping seeds in 48 hours.  For this reason, it is important to clean areas DAILY.