Question
Hi- my husband and I live in Virginia in a clay-rock soil area. Our neighbors had great success with grass seed "sprayed on" several very steep, rocky slopes. Is this as good a method as it seems and where can I find this service? Is it exceedingly expensive? (no pun intended). Thanks!  

Answer
Hydroseeding is becoming a popular way to sow lawns.  It is often unnecessary -- no one needs to hydroseed flat ground -- but for your property, it might be a perfect solution.   Your neighbor sound like ideal candidates - for hills and slopes, Hydroseeding rivals sod for effectiveness.  None other than Bob Vila (http://www.bobvila.com/HowTo_Library/Hydroseeding-Lawn_Care-A1744.html) claims: "Hydroseed typically germinates faster than seeds alone, because seeding requires several days of watering to reach the same level of moisture saturation the grass needs to grow."  Birds and squirrels, he says, would prefer that you not Hydroseed.  (On this point, Mr Vila and I differ - healthy soil will have just as efficient germination numbers as any Hydroseed slurry.)

This relatively recent process involves spraying the ground with a mixture of water, grass seed and a growing medium.  It's just like you were going to go out and spray-paint the backyard.  Special equipment is needed; don't expect every landscaper you reach to be able to offer it.  But obviously someone is doing it in your neighborhood since you have seen it done next door.

But I want to emphasize again - THIS IS NOT FOR EVERYONE.

It's a fun looking thing to do, sure.  And it ain't cheap.  But it's not on the level of, say, buying a Sub-Zero vs. a G.E. Monogram refrigerator.

And remember: That grass on the steep rocky slopes is going to have to be MOWED by somebody in Virginia.  It has to be watered, too.  Has your neighbor figured THAT out yet?  Frankly, I think instead of looking for a Hydroseeder, you should get yourself a webcam and set it up pointed straight over there and wait for this new grass to grow.   Because watching your neighbor with a lawnmower and his new grass (and who loves their grass more than someone who just paid agazillion bucks for some guy to Hydroseed the rocks on the side of the house?) is going to be worth paying for.  I see a new Reality TV series here.  And to borrow one of your phrases, Ratings will definitely exseed expectations.  I'll even advertise!

OK... OK.... let's talk about YOU!

I am figuring out you mentioned your clay-rock soil for a reason.  This is not a reason to Hydroseed.  It's the angle of the real estate that makes Hydroseed a good choice.  Hydroseeding is also cheaper than sod.  But so is regular grass seed.  Some landscapers use a green dye that tells the Jones "I hydroseeded!" but that washes away quickly.

My biggest problem with the whole concept is that more and more landscapers include the same old weedkillers and pesticides in the mix that goes down with the seed.  Once that happens, you're stuck with using them to take care of your lawn.

Let me tell you what I really think you should do.

If you have a steep, rocky slope, reconsider the Hydroseed option.  There are some stunning groundcovers that the Creme-de-la-creme Professionals would seize a chance at recommending over plain vanilla Grass that has to be mowed and watered.  Watch that neighbor's situation.  When the honeymoon is over, see how that marriage works out.  Get out the drumrollers when you see him open the garage and get the mower out... or you can just roll the drums while the Lawn Guy does it.  You can relax next to your groundcover with a cold Margarita and watch the show.

If however you are simply concerned about your clay-rock soil but you have a fairly horizontal, fairly level, lawn-friendly work surface, I have some news for you.

The rocks are a problem.  The clay is not.

First, congratulate yourself for getting a house with Clay Soil.  Because Clay is a WONDERFUL thing to have in your garden.

Surprised?

I know, I know - people complain all the time about Clay.

It's hard to dig into.  It's slippery when wet.  It's so nonporous you can make soup bowls out of it.  And it's a lot of trouble to correct.

Besides, if it needs correcting, there must be something wrong.  Right?

Urban Myth, my Virginia friend.

Clay is FILLED with vitamins and minerals!

The stuff is made of aluminosilicates (Al4Si4O10(OH)8).

And since Clay particles are NEGATIVELY charged, they are able to hold POSITIVELY charged ions.  And any soil that can do that is PACKED WITH NUTRIENTS.  Calcium, Magnesium, Potassium, and other plant nutrients packed with positively charged ions STICK LIKE GLUE to Clay!

Basic Chemistry!

Scientists give this special quality a number.  It's called the Cation Exchange Capacity - the "CEC".  The MORE CLAY you have in your soil, the HIGHER your CEC.

Remember - The more Clay a soil has, the bigger the CEC will be.

Sure, Sandy soil is great for drainage.  But it's the BIGGEST LOSER when it comes to Cation Exchange Capacity.  It CAN'T hold nutrients.  Almost ALL the fertilizer you put on grass you want to grow in Sandy soil, well, it just washes right through.  Not in 5 minutes, mind you.  Not even in 30 seconds.  AS YOU WATER IT IN!  

So thank the Lord for your Clay soil, Amy.  Do not let any landscaper tell you otherwise.

Clay also binds soil particles and holds moisture in ways that Sandy soil can only dream of.  We won't go into that today.  Because we have other things to discuss.

The rocks can be loosened and tilled.  While you incorporate organic matter into your Clay soil - Peat Moss, Humus, Compost, AGED Manure - in a ratio of 1:1.  These will correct the spaces between the Clay molecules and fortify your Soil with Nitrogen.

You can pick up Manure from your local chicken farm or stables.  Check Craigslist.com for someone who'll give you that for FREE!  Never again will you have to pay for Manure.

If you're concerned about the local landscaper not having enough of your business, send him over to pick the Manure up and deliver it to you.  Maybe he'll even put it down.  That'll keep him busy.  Just make sure he doesn't do anything stupid.  Like put down weedkiller or grubpowder or fungicides.  You don't need those.  You have Clay soil and the microbial life is intact.

If you're REALLY ambitious, in the spring, sow a nice cover crop.  Alfalfa comes to mind.  They will inject incredible doses of the most wonderful Nitrogen you have ever seen.  Earthworms from all over the region will come crawling over to your house, peering down into your garden soil to find a good place to live.  Microbes will multiply.  Hydroseed Harry next door will wonder what you have up your sleeve.

And then in autumn, till it under and sow grade A U.S. grass seed.

About then Harry should be writing to me, asking about groundcovers.

There's a lot of new material to digest here, Amy.  Sorry about that.  If some of this wasn't clear and you want an explanation, please let me know and I'll get into the Chemistry.  Remember: The Earth Is Round.

Hard to follow? Yes.

Will it work?  Absolutely.