Initial Plan to Tame the Lawn

This lawn is pretty big.  It is right at 2 acres and has never really been maintained.  It is overrun with weeds of various kinds and has many flowerbeds that have not been cleaned out in years.  It has fairly large iris beds that no longer bloom due to overcrowding.  The soil is sand and clay with little organic matter.  The entire place is overrun with sandburs and goat heads (also known as puncture vine.)

General lawn care calls for regular applications of broadleaf killer (like 2,4-D), regular fertilization, regular mowing etc.  But this lawn is gnarly.  Fertilization will not last since there is almost nothing to hold any nutrients.  It will take quite a while to get the soil to a level where it can be properly managed.  

I am starting with the things I can do.  I have been keeping the lawn mowed and I apply broadleaf killer regularly.  Normally, broadleaf killer only needs applied once or twice a year, but that is AFTER you get your lawn under control.  Here, we also have to deal with goat heads.  2,4-D will kill goat heads if treated early in their life cycle.  Goat heads germinate throughout the year, any time the conditions are right.  For this reason, goat head treatments need to be made periodically throughout the growing season.

Sandbur control is not so easy. Both sandburs and goat heads drop an abundant amount of seeds that can stay viable for years in the ground.  

I have two lawn monsters to take care of.  Here is my strategy for each of them.

Goat Head Control

Goat heads lay low to the ground and typically drop seeds before the plant gets tall enough to mow.  Fortunately, 2,4-D can kill them in their early stages.  So, for goat heads, I plan to apply 2,4-D at regular intervals to kill goat heads as soon as possible.  

It may sound odd at first, but I am also going to encourage as many goat heads to germinate as possible.  This will give me the opportunity to kill them.  Once they germinate, they cannot resprout from the same seed again.  If I kill them after they germinate, but before they go to seed, I can break their life cycle.

Sandbur Control

Unfortunately, sandburs do not have a selective control like 2,4-D.  They are a grassy weed and most things that will kill sandburs will also kill grass.

We have at least 2 different kinds of sandburs in the yard.  While I will have to kill them somehow, I do not want to kill the grass I am going to plant, too.  So, I will try to get as many of them germinated and killed before I renovate the lawn.

One type of sandbur that grows in the yard drops seeds after reaching about 12" tall.  This should be easy to control simply by mowing the lawn regularly.  That will prevent a new crop of seeds.  The old plants will need to be wiped out chemically or dug up by hand.  The latter is not feasible in a 2-acre lawn.  Fortunately, almost all bur weeds are either annuals or short-lived perennials, depending on the climate in the area.  A good cold Winter will kill them and they will have to resprout from seed.

My approach is going to be to pick the seeds, then kill the weed.  This sounds like a horribly long job (and it is) but it's the most effective way to get rid of sandburs.  Even if you wipe the lawn completely out, the seeds will remain viable for years.  By picking the seeds, then killing the weeds, I stop the process (or slow it down considerably) 

It also allows a little time for identifying the weed.  Sandburs initially look like grass and therefore are difficult to kill in early stages (without killing the grass.)  By picking the seeds and killing the weeds, I can be sure I have the seeds contained and I can also be sure I have the right plant to kill.

I have ordered a weed torch to make the job less difficult.  It will kill the weed and kill the seeds at the same time.  It will also prevent a lot of bending over to pick seeds.

Other Broadleaf Weeds

Broadleaf weed control is fairly simple.  You apply 2,4-D at selected times.  You try to get the majority of broadleaf weeds before they set seeds. That time is typically about the time dandelions start popping up.  Apply 2,4-D after dandelions pop up and BEFORE they turn to puff balls. 

Grassy Weeds

Grassy weeds are the toughest to control since they are basically grasses that are undesirable.  There are only a few grassy weeds that are impacted by selective herbicides.  Generally speaking, controlling grassy weeds is a manual process.  You identify them, then kill them one at a time.  

There are a few exceptions to this, however.  Nut Sedge grasses have selective herbicides available that are quite effective.  Sedge Hammer works very well, but only on one type of Nut Sedge.  Sedge Ender is good on most types of Nut Sedge.  Finally, Tenacity is the go-to herbicide for Nut Sedges of all kinds.  It is quite expensive, however.  I typically hit Nut Sedge with Sedge Ender a time or two and see how well it controls it.  Then and only then do I hit it with Tenacity.

Woody Pests

Woody pests include sapling trees, vines and some grasses (like Bermuda grass.)  These can all be controlled using a brush and stump killer that contains triclopyr. The nice thing is that triclopyr will not harm most lawn grasses (except Bermuda grass.)

Soil Amendments

Amending soil can be an easy task or a difficult task, depending on where the soil is at vs where it needs to go.  Unfortunately, this soil is not very good soil at all.  It is mostly sand and clay.  Adding fertilizer will help, but it will spend quickly and wash away readily.  The soil needs something to "hold" the nutrients and life.  

I always mulch when I mow.  This will help start building topsoil. Unfortunately, there really isn't much to mow in most places.  The yard is very barren (except for weeds.) It is likely that parts of the yard will need helped out with compost or other amendments.  

I am looking into several possible amendments for the soil including compost, biochar and composted biochar.  Peat moss may also be used.  All of these have limitations because the lawn is so large.  Applying 1" of compost would require about 275 cubic yards of compost.

Soils test have determined the soil has no nutrients.  The Nitrogen level was so low, the test barely registered anything. It is recommended I start with 40 lbs of nitrogen per acre.  That is 80 lbs of Nitrogen, total.  While that doesn't sound like a lot, you have to understand that fertilizer is not all Nitrogen.  A 10-10-10 fertilizer is just 10% Nitrogen (the first number.)  It will take 800 lbs of 10-10-10 fertilizer to deposit 80 lbs of nitrogen in the soil.  Also don't forget, that in a sandy soil, most of this Nitrogen will just wash away after a few rains. 

De-Thatching

Eventually, this lawn will need de-thatched.  This brings up an issue for the first few de-thatchings.  Ideally de-thatching will be done about every 2-3 years, but only if needed.  This lawn needs it BAD!  The problem is that de-thatching will produce a lot of thatch that needs to be disposed of.  This thatch likely will contain seeds from undesirable weeds.  Normal thatch can be composted, but not from the first 2-3 de-thatchings of a new lawn.  Composting will kill a lot of seeds, but some seeds will survive the composting.  Mainly, seeds like crab grass, puncturevine and a few others will not be killed by the heat generated in a compost pile.  For this reason, I plan to process the thatch into char, then compost the char.