Prepping your garden soil

While the climate down here is wonderful for growing a wide range of plants, the soil often leaves much to be desired.  Seems you either get clay or sand if you live in or near Houston.  In our favor organic material breaks down quickly and you can build a nice soil base before too much time goes by.

Proper soil preparation can make all the difference in how well your garden grows.  You will want to work 3″ to 6″ of organic material into your clay or sandy soil before you begin to plant.  You’ll want to work this into the top 12″ of soil.  In addition you will want to add a 3″-4″ layer of pine mulch every year.  Organic material breaks down quickly in our heat.  So you need to keep replenishing it. ( soil amendment materials: pine mulch, compost, peat moss, perlite, sand )

A proper soil test is also needed to tell what fertilizers need to be added.  I’ve found a good time release 10-10-10 4-6 times a year is needed in my yard, spread at about a pound of nitrogen per 1000 sq ft.  I also add a handful ( 1/4 cup ) of iron to each shrub and tree each March.  As organic material breaks down it used up the nitrogen in the soil.  And each and every heavy rain we get washes away a large amount of the nitrogen in the soil.

Drainage is the next issue to consider.  Sandy soil drains rapidly and standing water is not a problem. Adding organic matter will help the sandy soil retain moisture longer.

Clay soils hold water, and even if you improve the top 6″ to 12″ of soil, often the clay underneath retains water.  Adding sand or perlite or both will help.  Before planting watch how quickly the water drains after a heavy rain.  If it takes more than one hour you’ll want to help the drainage with drains.

Plants prefer slightly acidic soils.  While these can occasionally be found in Houston it ‘s more likely your soil pH will be around 8.0 ( slightly basic ).  Changing a soils pH long term by a more than a small amount is unlikely.  But you can add lime ( makes soil more basic ) or sulfur ( makes soil more acidic ) to help.  If you have basic soil add some peat moss each time you plant a new plant to help reduce the soil pH.

Worms help, you can purchase live worms, or as I do add worm castings to your garden each year.  It seems to attract them.  I always find more worms in areas I ‘ve added castings.

If you work clay soil while it is wet, it is likely to compact on you forming a brick like substance that your plant’s roots will be unable to push through.  Wait until the soil it dry to work it.  Or as we did up north lay out 12″ planks and walk/stand/kneel on them to work.

To convert lawn to garden:

1) Apply RoundUp or another weed killer about a week before prepping an area.

2) Scrape off sod

3) Add soil amendments ( 3″-6″ deep ) and work into soil about 12″ deep

The easiest way to work soil additives into the soil is to dig a 12″ trench, then dig a second trench right next to it, filling the first trench with the soil from first plus additives.  Continue trenching your way across your new garden.


1) Apply RoundUp or another suitable weed killer about a week before prepping area

2) Lay newspaper 3-6 sheets thick across entire area

3) Cover newspapers with 6″ of soil, mulch, peat, sand, and compost

Learn more about soil:
Lessons on Soil ( 1911 Russell )
Crops and Methods for Soil Improvement ( 1912 Alva )

2 thoughts on “Prepping your garden soil

  1. I think advice for our area when it comes to vegetable gardening or cargening with annuals is pretty straightforward. But to me the more difficult question has always been what to do when trying to grow perennials in a clay soil with no natural drainage. That pretty much the situation in a good part of my garden.

    Years ago I studied this question, and the idea of raising large areas of my garden seemed impractical. So I turned to a very controversial alternative: I incorporated huge amounts of the sharpest sand I could find. Over and over I have read not to add sand because it will cause your soil to turn to brick. But my experience has been just the opposite. For example, I have one particular area that was prepared in this manner over 20 years ago, and the soil texture is still wonderful. I think the main reasons I have done so well with this method are 1. I use a very large amount of sand compared to clay:anywhere from 30 percent sand to 50 percent sand. 2. I make sure to break up the clay at a time when it is at just the right moisture level. 3. I break it up into golf ball size clods. 4 I carefully avoid walking on the areas where I have put sand.
    I have every intention of using this method in the future. My perennials seem to love it.

  2. I have read that you can add sharp sand or ‘bank’ sand to clay soils and it will help provided you add enough sand to make the soil half sand. I haven’t yet tried that.

    I’m glad to hear the sand works so well. Adding organics is an ongoing process because everything breaks down so quickly here. Less fast if you don’t turn the soil over when you plant, but I find that hard to do.

    Maybe I’ll try that in the next section, there’s still a 3′-4′ x 15′ area of lawn that needs to go away this year.

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