Question
Hi Jim,
We live in Northern Calif. where rocks grow as fast as weeds. We have recently installed a completely new septic system that has destroyed our back and side yards. Many rocks have been removed and the ground is very unlevel due to the backhoe and refilling of trenches. We have a big job ahead of us in repairing our yard and are really not sure where to begin. We do plan to bring in top soil but much has to be done before that process.Any advice would be appreciated. Thank you!

Answer
Hi Toni,

>>"...rocks grow as fast as weeds...?"

Without a visual inspection of your lawn and landscape situation, I can only offer some general suggestions based upon the information you have provided here.

There are all sorts of 'rocky-soil' scenarios.  As far as establishing a generic lawn scene, you may have some serious problems.  If the rocks cannot be sufficiently buried by adding better soil, you may want to invest in efforts to 'de-rock' the areas that you intend to make into lawn.  Removing lots of rocks from even a small area can be an extremely labor-intensive effort. If your de-rocking efforts need to involve such strategies as using a 'sifting-screen' process to become rock free, then maybe you should consider other landscaping scenarios.

 In general, a geology and terrain which is inherently rock infested is naturally adverse to the turf-grass plants which have evolved over the millions of year to need the prairie or savannah habitat.  These grass-land ecologies almost always have at least several inches of top-soil for the grasses and present no problem for the many types of grasses that send their roots sometimes many yards deep into the ground,...un-obstructed by rocks below.

Given these facts about the grassy plants needs,... You may want to seriously consider only working hard for a smaller 'lawn proper' area near the house,...while going more with Nature to establish 'alpine' and 'rock' gardens or similar specialty gardens for the rest of your lot.  These constructed areas  can blend in with the rocky scene that already exists and be properly planted. It may even be more practical for you to forget about having any lawn areas at all.   So much will depend upon your determination to have a normal lawn and how rock-compromised your soil is.  The idea is this,...you can only botanically defy Nature so much.

Alpine garden, rock-gardening, and similar landscaping scenarios can be great alternatives to a typical lawn scene. And you may find your are blessed with something better than the blah lawn potential.  These alternatives can work-out to be great hobbies too.  On the web you can search for the many specialty nurseries that supply alpine and rock-garden plants. You may have a local horticulture club that has rock and alpine garden enthusiasts in your area.

If you can manage some alternative plans and consider establishing an ecology which is more in line with the rocky terrain that already exists, you may find that you don't need to worry so much about removing the rocks.  You may just need to work them into a rock-garden theme.  In fact you may want to ADD some more interesting rocks and make the entire area into an aesthetically great rocky landscape with the appropriate plantings. People who are ardent alpine and rock gardeners often enjoy collecting new rocks as much as new plants. And a fossil here and there only makes it all the more interesting. (No reference to grandad!)

If and when you do truck in any better top-soil, you should use the very best available.  Top-soil suppliers will usually offer a variety and some will sell a 'RICH-MIX' blend that will be the best for improving the top-soil. The supplier may permit you to formulate these blends as you want.  Your rocky-based soil probably should NOT have any sand added to it.
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Only Use plants and grasses rated for your climate-zone.
HORT ZONES from ZIP CODES:
http://www.arborday.org/trees/whatzone.html

To help you decide what plants to use and where to place them check-out the "PLANT SELECTOR" applet:

www.growit.com/Bin/PSelect.exe
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GRASS-TYPES for Rocky Soils:

The hardiest grass-type for poor soils is Bermuda Grass (for Zones 6-9).  This grass can grow with a minimum top-soil base, but it needs lots of sun-light.
The cool-climate grass-types generally need a deep-soil to do well.  You may try these types (Fescues and Tall Fescues), but may have to re-seed them ofen to keep an area densely covered.

California Hybrid grasses:
http://www.turfmerchants.com/
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PLANTS for ALPINE and Rocky Soils:

http://www.growinglifestyle.com/article/s0/a146126.html

Alpine Garden Society:
http://www.backyardgardener.com/index2.html

Use key-words 'alpine gardens' 'rock gardens' at GOOGLE.com for many hundreds of web-sites.
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With a good fertile-loamy well draining top-soil, best quality hybrid grass type(s), 1-3 inches of water per week, plenty of sun-light, ...almost anyone can have an excellent lawn with a minimum maintenance effort.
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I Hope this has answered your question(s)!

Visit my Lawn & Gardens webpage for more Tips, Facts and Links:
http://hometown.aol.com/eilatlog/lawnol.html

Your Questions and Comments are welcome at ALLEXPERTS.com