Question
My lawn is majority zoyzia grass, however, it seems to be being overtaken by some kind of weed which has a purple cluster at the top. I basically have three questions:
A) what is this weed and how do I get rid of it?
B) Although the zoyzia has not spread completely throughout the yard, what can I do to either foster growth or fill in areas until the zoyzia spreads?
C) what type of fertilizers/weed killers should I use and when should I use them? I live on the water (waterfront)in Southern Maryland, so whatever I use needs to be environmentally safe.

Also, if possible, please provide some websites where I can go to help me develop a healthy zoyzia lawn...Thanks in advance....Rick

Answer
Zoysia is that miracle grass everybody loves for low maintenance and density.  This is an easy lawn to care for and if you can keep it healthy, Rick, your problems will be over.

Unfortunately, it is not healthy right now.

Best thing for sick grass:  Build up your soil.

That means no chemicals.  We are clearly on the same page.

Now, it's one thing to tell someone, 'Get on an organic program' and tell them how great it is blahblah.  It's another thing to give them instructions on what to do.  Details, details.  That's what makes the world go round.

So this is going to be a little longer than you probably expected.  It's also why I'm back up 22 questions.  AllExperts is not too happy about that.  But this is important.  And that's why people write to me.

Right now is prime time for Corn Gluten Meal based weedkillers.  I picked some up at my local garden center this past weekend under the name 'CONCERN WEED KILLER'.

I say that because most people go to the garden center or Lowes or Home Depot and ask for Corn Gluten Meal Weed Killer, and the sales people look at them like they're from Mars.  You have to look for the right product.

Right now, this formula appears in large bags of yellow powder as 'DYNAWEED', 'SAFE N SIMPLE', PROPAC, CONCERN WEED PREVENTION PLUS, etc.  One new formula puts this in granular form to ease use with Rotary and Drop spreaders. You put this down right now, as the Forsythia buds are beginning to break.  A bag costs anywhere from $25 to $30.  It keeps all the weed seeds in your grass that landed there last fall -- Dandelion seeds, Crabgrass seeds, all annuals -- from germinating.

This was discovered quite by accident at Iowa State by some researchers working on problems with grain storage, which is a big problem out there in the Midwest.  They realized that seeds were not germinating when they were in contact with the Corn Gluten Meal.  Someone applied for a patent and now they license it, selectively, as a pre-emergent, patent-protected weedkiller.

The Scotts Company by the way is not one of their licensees.  You won't see this stuff used in any Scotts commercials.  It's not the way they do things, not yet anyway.

Now, everywhere you look, anything you read about Zoysia will tell you one thing about fertilizing:  It needs very little, if any.  It's one of the pros of growing it.  The Corn Gluten Meal weedkillers, which ever one you pick up, ALL break down into a good, healthy Nitrogen fertilizer.  Put this stuff down and you won't need anything else for your Zoysia, Rick.

Best of all, it won't kill fish, it won't hurt any animals, it won't make anybody sick, it will build up your soil and do terrific things for YOU with all these benefits.  No nasty side effects, no skeletons.  Just good, clean, American grass.  I just love this stuff.

In late May, when your Zoysia is turning green, get yourself a core aerator and pour some air down into that Zoysia to give it a boost.  Keep the plugs down on the grass; they'll break up when you mow.  This is a regular maintenance chore that just comes with the territory when you commit to Zoysia.  A minor, infrequent inconvenience.

One serious word has to be said about Mowing.  This is not a big deal with Zoysia to the extent that Zoysia grows slowly and especially in the northern areas (you are in the north as far as Zoysia is concerned), Zoysia grows slower and needs less maintenance.  But Zoysia needs mowing when it needs it.  Don't underestimate the value of diligent mowing of Zoysia.

FYI: All grass has a 'collar' where the blades originate.  When you mow often, that 'collar' is located near the surface of the soil.  But when you delay mowing, that 'growing point' rises above the soil surface.  Then, when the lawnmower runs over that grass, it slices the collar off.  That's why diligent attention to mowing really pays off.  You want that growth from the collar to remain at the soil surface.  It's a critical part of the puzzle.

How high?  That depends on the Zoysia you used.  Zoysia japonica -- coarse-bladed Zoysia -- responds best kept to 1 inch high.  Zoysia matrella -- the fine Zoysia -- grows best mowed slightly shorter, at 3/4 inch.

Back to your soil.  My guess is that like most homeowners you have not done anything positive for your soil, maybe ever.  To improve it, rev up the biological activity down there.  There are things you can put down that make it convenient to do.  This is one of the best things you can do for your grass, raising the fertility of your soil.  Find a garden center that sells the Organica line of products; they have a liquid 'booster' type of product that you can drizzle or spray onto your soil when the weather gets warmer (microbes are active then).

Now, we still have one more problem.  Those bare spots that your Zoysia has not filled in yet.

One reason it's a problem is that preemergent weedkiller we talked about much further back.

That Corn Gluten Meal will kill anything you try to plant as seed.  It won't destroy sod or plugs.

So I would do one of 2 things:

1.  Plant a 'cover crop' which in July will be seeded and will act as fertilizer for the grass growing there in the future (one of my favorites is White Clover, which injects megadoses of Nitrogen into the soil, a gourmet treat for spreading Zoysia), or

2.  Put down more Zoysia plugs or sod.  These will not be affected by the Corn Gluten Meal -- not negatively, anyway; they will love the slow release Nitrogen that pours out during the summer.

Now for some reading material:

Kansas State has a cheat sheet on Zoysia: http://www.oznet.ksu.edu/library/hort2/mf683.pdf

The Univ of Fla IFAS Extension Service posts a paper telling you all about Soil Organic Matter and how it will fight germs and keep your grass healthy: http://edis.ifas.ufl.edu/VH037

and here's one on mulches from Univ of Chicago Coop Extension: http://www.ag.uiuc.edu/~vista/html_pubs/mulch/MULCH.html

The Maryland Cooperative Extension Service offers local advice with your tax dollars at work.  Oddly, their service is not in step with the organic moods of the times, which is typical of most of the Coop Extensions around the country as well as agricultural schools, but they'll come around eventually: http://extension.umd.edu/http://extension.umd.edu/

The Texas Coop Extension notes that Zoysia is a great option even as far north as Maryland in its Zoysia page: http://plantanswers.tamu.edu/turf/publications/zoysia.html

The USDA posts some (to me) fascinating points on soil microbes which I just add because it is so comprehensive: http://soils.usda.gov/sqi/concepts/soil_biology/soil_food_web.html

Pike Nursery posts info on Zoysia for its customers but anyone can read it, just the facts plain and simple: http://www.pikenursery.com/stories_php_loc_02_03_06.html

Seedland.com, which sells Zoysia grass plugs, seeds and sod, develops the pros and cons of this grass on their website; for side by side photo comparisons of different Zoysias and other information see their Zoysia page: http://www.zoysias.com/

'Amazoy Zoysia' is sold by one of the oldest Zoysia farms in the country, Zoysia Farm Nurseries in Taneytown, MD, which posts testimonials and some basic facts about the care and feeding of Zoysia: http://www1.zoysiafarms.com/testimonials_midatlantic.html

Finally, note that birds are your best friends and you should do anything possible to keep them happy and healthy.  Plant trees.  Put out bird feeders and keep them stocked with seed.  Get some birdbaths and make sure they're filled with clean water, especially in the hot summer.  By not putting down pesticides, you keep your grass healthy and the birds will love the bugs that follow.

I hope this helps, by now it's probably time for your dinner, so I'll stop.  For me, it's almost time for breakfast now.  Better get some shuteye.

Thanks for writing!  Any questions, I'm here.  But boy is there a line...