Planting Soil...

[Oren]

Hello,

I live in Southern Nevada (Mojave Desert) USDA Zone 8a.

This is a difficult place to grow a garden, but yesterday I found some information that got me excited about growing tomatoes. The lady has a book with many details for growing in the harsh desert.

Our soil here is hard packed, plenty of rock and difficult to grow anything.

Reading on I found out that some soils are made with "biosolids" (sewer sludge). From my reading it was pointed out that this information is not unnecessarily reported to the consumer. Apparently this is some "nasty" stuff to be growing food crops in, since it contains things that are not removed at the sewer treatment plants.*

Questions: What can I use and combine to make my own soil? Are there products that I can use to ensure the soil is safe?

Thank You.

[Billy]

You want to avoid biosolids for a garden, or wherever you may want a garden in the future (heavy metals).

You want 18 lbs. of chicken manure (or its equivalent)/100 sq. ft.. There should be 5% to 10% organic material in the soil.

30% - 40% sand, 30% - 40% silt, 20% - 30% clay If you scrape away the top inch or two of dirt, then dig a sample from a hole with vertically straight sides, put it into a large glass jar with water, and shake it hard to mix it up, then the sediment will take 24 hrs. to settle. The bottom layer is sand, the middle layer is silt, and the top layer is clay. The thickness of the layer divided by the total thickness of the total deposit gives the percentage of composition. You'll want to pull out the rocks as well. Use them to build a nice fence.

It would probably be easier to build a raised garden, or to use pots.

Good luck.

[Billy]

The first thing a gardener does is to learn how to grow soil. Soil that is economical, and nurtures, without poisoning the environment.

[Nad R]

Snip...

Many years ago their was an episode which I do not remember. The show had this one guy with a beautiful garden in the desert. He had a high walled one acre yard with a small home inside the walled area. The place was surrounded by a brown dusty town and inside the gate a beautiful garden. The high walls blocked the wind and provided shade for the plants.

He had a massive water management system that captured very rain drop and an automatic drip watering system. The landscape itself had stone paths that had water to flow into a cistern. He also had patios with open roofs of two by twelves that blocked much of the harsh sun light for the more delicate plants.

I have a feeling soil building is not going to be your main problem, it is water and providing shade for the plants in a harsh environment. When you add water to your soil soil does it turn: clay like, sand like or does the water stay in it with nice loamy texture?

[Billy]

That's not the question that he asked. Oren asked, "Questions: What can I use and combine to make my own soil? Are there products that I can use to ensure the soil is safe?"

The first questioned was answered. As to the second question, it is a lot like cooking: use the best ingredients and the best practices.

Since cool air stays closer to the ground, walls act as a container to keep the coolness from flowing away, and offer some shade. Overhangs, like covered porches, protect the house's walls from being heated by the sun, permitting them be a source of coolness.

The Moorish/Spanish walled courtyard would help moderate temperatures, see pictures below. Most probably have too many paving stones, but they will give you an idea as to what is possible.

[Nad R]

When he mentioned southern Nevada, it just brought back the memories of that tv program. After all I am no expert in that area since I still have snow on the ground and 25 degrees outside. Soon to start indoor seed starting and longing for spring.

[Billy]

I hope to start germinating cool weather crops in early February. I'm just starting to get some sunshine for part of the day, as the Sun works its way back above the tree line on top of the hill.

[Gunner]

Pretty pictures, just the wrong conclusion, the Moors brought their water gardens and irrigation for plants and trees to Europe which then spread thru the New World. Water being the key factor here. That "container/wall " cool air flow was a good theory but it doesn't work that way. Especially at night when those large masses relaease the heat and keeps cooking those plants. The shade part is correct.

[Gunner]

You are correct Nad, water is the key to any survival a desert environment.

Oren do ask your local growers, master gardeners in your area and the county extension office for assistance. I recommend you test your soil to find out specific mineral content. Desert soil often contains high levels of minerals. One does need to consider the water pH factor, most areas of the Desert SW have very high pH locking up and/ or giving excessive nutes to plants. Testing soil and water is important and cheap compared to continuously buying additives. Additionally you have the potential for surface desalinization. You can win a few battles but you will not win the war on the desert.

I have seen some beautiful gardens in the SW but mostly their natives or similar environment plants, wise irrigation and proper orientation.

I do need to put a plug in for Hydroponics and Controlled Environment Agriculture (CEA), the fastest growing area in the world's desert environments. In that approach you don't need to mess with nor contribute to soil problems and you conserve water, using about 1/10 the amount.

BTW do go reread your reference on biosolids, There are different classes and National Standards used by most states. Regardless just know that many do not contain all the heavy metals that billy said plagued the White Hose. My concern is no one is testing for the increasing pharmaceuticals.

[Gz]

broken up with thicker sand particles. Keep mixing things in and you will have good soil.

There is heavy metals in sludge and sometimes you will find tomatoes seeds growing in it at the plant. Also marijuana.

greg

[Billy]

Make your soil adjustments, sand, organic material, and then check-out lasagna gardening (aka: sheet mulching).

You may want to dig your garden to mix in your amendments, for the first season, after that it is no-dig gardening that uses mulch to suppress weeds and to conserve water.

[Gunner]

[Gunner]

Any seed growing in this sludge is from the organic material they use for soil mix, not from the sewage treatment process

As for heavy metals, Class A is the only one approved for home lawn and gardens and should contain levels less than most background levels There is also another type of biosolids above the class A called Exceptional Quality. This is preferable to use. Again you can research the max allowable levels of heavy metals in each class. The Exceptional Quality is recommended bt the many Master Gardener Association here in the PNW, still as a safety precaution I do not recommend it for anyone with a compromised immune system or other health problems.

Having said that you need to beware that many sand/gravel places will use lesser classes of biosludge to make their compost mix, further mixing that with other soil to make their top greade garden mix or they gather up the waste from a cut site that was previously sprayed with lesser quality sludge.

I also do not recommend adding sand to desert soils. Never have seen it to work well even with drip irrigation expect for melons. They were a desert plant to start with.