Our good Sierra foothill soil

Our ‘bad’ soil…?

I get comments all the time from discouraged local gardeners about ‘our bad soil’ in the Oakhurst, Coarsegold and North Fork areas.  Giving this some thought, I’m wondering if gardeners are making use of the natural ‘mulch’ we have in pine needles and oak leaves?  Using the resources we have here was a strategy I used mainly for economy.  With a large property, you can’t be spending money on a few bags of purchased mulch and make much of a difference.

After some reading and some research and my own experience in this new garden of mine, I’ve made peace with the soil in my garden and learned many of its ‘good’ points.  here is what I learned

2006- Planting Western sword fern and heuchera

2006- Planting Western sword fern and heuchera

Each year, in my planting areas, I add either one of these to start out the new Spring season.  As I weed, I turn over the mulch from last year with my trowel picking up a 1-2″ later of dirt.  This incorporates the mulch into the soil and eventually improves the texture of the soil.  This could be called a form of sheet composting.

 

Decomposed granite

Decomposed granite

Soil Texture

I think it’s the hard texture of solid seeming clay and gravely decomposed granite that discourages gardeners and leads them to replace much of the soil in planting beds or cause them to give up entirely and limit themselves to container gardening. Adding mulch to both of these soils solves the problem.

My only regret, however is not replacing the soil from next to my newly built home.  The concrete remnants left in the soil 1 to 3 feet around the foundation have given me fits and caused many failures in landscaping plants.

Loamy soil is the ideal and we are lucky to find it under our oaks and pines where years and years of composted leaves have contributed to the soil.

Both clay and decomposed granite have plenty of nutrients for growing healthy plants…I don’t think it’s the minerals in the soil that is the problem.

Thick clay needs organic matter added to make it plant friendly

Thick clay needs organic matter added to make it plant friendly

Mixing in mulch

 If you have areas of clay, cover it with oak leaves and turn the clay over on top of this, breaking up as many of the solid clods as possible.  If you do this methodically, eventually your soil will improve. Rake up oak leaves and use them to your advantage, mixing them into your beds and planting areas. The fact that they ‘never decompose’ is a good thing!

After adding and mixing in layers of natural mulch into my soil for the last few years, I now have wonderfully friable and workable soil. The ground is lovely and soft from the rain in Spring and a dream to plant in.

It’s getting easier and easier to plant.  The soil is full of earthworms, and I see the whitish threads of mycorrhizae, the good soil fungus that helps plants absorb nutrients from the soil.  A mulch layer of fresh pine chips is also going to house beneficial predatory insects. The best thing about adding mulch to soil, is the texture which is loose and fluffy, all the better for plants to grow!

Autumn sage from the 'Ugly Plant' sale

Autumn sage with pine needle mulch, stones hold the plant and water

Soil Ph

Soil pH is a measure of the acidity or alkalinity of a soil.  Most plants grow best in slightly acidic soil — pH of six to seven.  Blueberries Azaleas and Rhododendrons love acid soil and need a pH of around five.

Barring just buying acidic soil at the store, your best bet for potted blueberries or azaleas, is to find an area of your property where the oak or pine leaves have composted for years.  Dig into that and use it to plant your acid loving plants. Azaleas and Rhododendrons in the ground also benefit from pine needle or oak leaf mulch, and especially your own kitchen compost..

Ash from a burn pile is ideal for use in patio pots.  Dig down into the scorched soil underneath he oldest burn pile you have and you’ll find the best ever ‘potting soil.’  Decomposed granite is also acidic.

What you want to avoid when planting is clay or soil that looks like the desert would,..where salts and heavy deposits of minerals may lie.  For clay soil add lots of organic material such as compost or composted leaves or pine needles.

Questions:

Are oak leaves or pine needles too acidic or toxic to plants because of the tannins they  contain? Can I use pine chips, needles and oak leaves?  Linda Chalker-Scott, professor at Washington State Universityruns the Garden Professors blog. She says, “Don’t worry about the tannins. It’s a non-issue in the landscape. Use them!”  All our leaf mulch from oaks works fine, too.

Does mulch attract termites or other pests?
No. Many wood-based mulches are not attractive to pest insects but are actually insect repellent. Mulch does not bring in termites. Termites don’t like wood chips.

Aren’t wood chips a fire hazard?
A: No. Coarse textured organic mulches, like wood chips, are the least flammable of the organic mulches.

Won’t wood chip mulches cause nutrient deficiencies in plants?
A: No. Many studies have demonstrated that over time woody mulch materials will increase nutrient levels in soils and plants.

 

When planting on a slope, place a rock on the downhill side to anchor it and keep water longer near the roots

When planting on a slope, place a rock on the downhill side to anchor it and keep water longer near the roots. Mulch with pine needles or chips.

A fun, homespun soil test

You can buy a soil test, but I never have done this. You can test your garden soil pH with vinegar and baking soda

Collect 1 cup of soil from your garden and put 2 spoonfuls into separate containers. Add 1/2 cup of vinegar to the soil. If it fizzes, you have alkaline soil, with a pH between 7 and 8.

If it doesn’t fizz after doing the vinegar test, then add distilled water to the other container until 2 teaspoons of soil are muddy. Add 1/2 cup baking soda. If it fizzes you have acidic soil, most likely with a pH between 5 and 6.

If your soil doesn’t react at all it is neutral with a pH of 7 and that’s pretty lucky!

 

See Wangling wood chips from work crews for how to get FREE mulch.

13 comments

  1. Carol Demann -

    I have been doing the same also adding a good planting mix as well with some sucess .

    I live on the south fork of the American River and it is so hard pack clay and rock It is very hard to grow anything but weeds

    I have had luck with Lavender , Rock rose, Grasses,and Sage but miss my favorite Echinacea. because it is so rural we have alot of DEER I used to like them now I am ready to hire a Hunter ! I am a Previous Orange County person where I gardened all year but hear it is such a challenge ..

    • Sue Langley -

      Hi Carol,…good to know that you are finding the same things work for your soil. Try ceanothus(wild lilac) Russian sage, Phlomis (Jerusalem sage) and catmint. All are decorative and deer won’t eat them..
      I know it’s not funny when deer bite off the flowers and then decide they don’t like what you planted! I lived in OC, too.

  2. Curbstone Valley Farm -

    In think most gardeners probably have less than ideal soils, without investing some effort in amending them. Our soil here is almost too friable, as it’s so sandy, so the soils struggle to retain moisture, and nutrients. It is amazing what just a little organic material can do to transform a soil though. I’ve been working on some areas here for 6 years, just a little at a time, and the difference from when we first arrived is remarkable. I hope your post gives some others some encouragement. Choosing the right plants for unique soil conditions helps a lot too. We certainly won’t be growing tea roses here any time soon 😉

    • Sue Langley -

      I think the key is loosening, or in your case enriching the soil enough so the roots can push through or water can be retained.
      All the ‘good’ soil has been that which has been covered naturally with leaf litter. Our ‘bad’ soil is what’s left after grading for the house building, the usual cut and fill where they scrape down a bank and push the soil out level.

      Unfortunately that is ten feet all around the house where we’d like landscaping. It’s been slow growing there because we didn’t replace the topsoil. I would say it’s taken 6 years of mulching, like you, to get it in good shape.

      The solid clay bank, however has been the home for rosemary, lavender, rockrose and three thriving Howard McMinn manzanitas.

    • Sue Langley -

      You’re welcome! The best soils are those covered naturally with leaf litter and if our gardens don’t have that, then it’s good to replicate those conditions with layers or different kinds of mulch. When our house pad was graded and the clay bank was laid bare, the first thing I thought to do was cover it with pine needles, oak leaves and soil from the surrounding area.

      In California, you don’t really have bad soil unless you’re in the 9000 acre Coalingas ‘benitoite badlands,’ where there is the serpentine mineral chrysotile in the soil and nothing grows OR in the city.

  3. Carole Sue -

    I’m so glad I found your web site. I’m working on sustainable gardening (veggies, fruit, etc.) at 3500′ on the edge of the Plumas National Forest. Do you worry about acidity build up with pine needle mulching? Also, loved your article on deer resistant plants but found they love my Japanese maple. I use deer resistant spray to protect vulnerable plants where they are not fenced.

    • carol demann -

      Hi Carole I am concerned about Aciidity build up so I use the oak leaves for most but also use a good organic soil and also use organic Bone meal that realy helps. I thought I had lost my tomato plants because being on the River we had. 3 days of a morning Freeze (25) I didn’t see this coming but before I found time to tear them out I found new leaves so I cut back the dead and I now have my tomato plants back

      • Sue Langley -

        Hi Carole,
        I reason that planting mostly CA natives and Mediterranean plants are suited to our native soil. I try to loosen it and add native organic matter to keep things percolating along.

        I rarely buy soil except for containers and sometimes mix my own using native soil, sand from a tiny stream on the place and ash from burn piles. The soil under a burn pile is lovely rich and crumbly.

    • Sue Langley -

      Hi Carol, during a workshop, I was asked this question about acidity, so I did a bit of research. The tannins from oak and pines is not enough to affect the ph of the soil and the health of the plant. The tannins do color water that they sit in, like birdbaths, so it’s a bit off-putting, but I’ve been adding both oak and pine leaves to my soil for 7 years now with good result. AND, much savings! Some plants love the extra acid, like rhododendrons. My garden has an oak or a pine about every 20 feet, so all my garden is planted in oak and pine litter covering either DG or clay.

      What’s frustrating about deer resistant plant lists is that deer eat different things in different locations sometimes. It’s tricky business. I’ve listed the ones resistant in my garden, that I’ve tried because I found them on a plant list Then you do the actual ‘testing!’ Thanks for your kind words!

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