How to Plant Mesquite in Clay soil and/or Non-Dessert Areas. That is easy. The best way to plant Mesquite is in a combination of sand, clay, compost and pumas. Yes, pumas. It is also known as lava rack. It can be purchased at any home improvement store. It can be found in the landscaping section, next to the cement posts and walkways. Mesquite is a South Western plant used for making charcoal and adding flavors to food when barbequed. However, that is a waste of its usefulness. The real usefulness is its ability to be a legume like a fava bean plant. Yes, it fixes nitrogen from air into soil. It also provides a filtered shade for understory plants. Understory plants love to grow up into it.
It can survive in hot climates like Southern California and Arizona because of its tap root. The tap root can grow to at length of 30 to 40 feet in depth. This is far enough to hit water tables and shallow underground springs. When planting a Mesquite tree, it is important to straighten out the tap root to point straight down. In most cases, the tap root will have bottomed out in the pot and started to circle around the bottom corner of the pot.
Below are a series of instructions how to plant an Arizona Mesquite tree in the Bay Area with clay for soil. Below is pictured what we will end up with. The tree is in the mow strip with grass/lawn surrounding it. The lawn is not your typical lawn. It has an underground irrigation system designed to encourage grass root growth. In this case, the lawn system has been in for 5 years and the grass roots are around 18 inches long. We will see that in later pictures.
1) With most dry and clay soiled environments, we need to start out with watering the area where we are going to dig. If not, the soil can be so hard and dry and it will break our shovel. Water the area for about 30 minutes and then wait about an hour to let the water absorb through the soil.
2) Start digging a whole. In this case, I am trying to change the soil type. The hole is about 3 to 4 feet in diameter and about 24 inches deep. Notice the irrigation system in the hole. They are the two pipes pictured. They have a drip emitter every 12 inches, squirting out about 1 gallon of water per hour. The lawn irrigation system is run about twice a week for 10 minutes. Anything more and the grass start to die.
3) The irrigation system needs to be “shorted” so it does not water the tree. In this lawn application, there is way too much water being delivered to the area. The tree will drown in this situation. The lines need to be cut and re-routed. The white PVC pipe is the main feed for the irrigation system. It is really in a bad spot, but nothing to fear.
4) Before connecting the final re-routing pipes, the irrigation system needs to be flushed.
Below is pictured the re-routing pipes. Leave one side disconnected to allow flushing.
Flushing pipes. While the water is still on, grab the pipes and connect them together. This will prevent any dirt getting into the drip lines.
5) Next is the soil. The soil that is backfilled into the hole is made up of 30% pumas, 20% wood bark mulch, 10% sand, 10% local grown compost and 30% native soil. Dump it into a bucket or wheel barrel, mix. It does not have to be perfectly mixed. Use a folding technique while mixing, it works the best. Back fill the hole to about half way up.
6) Pictured below is the pot of the tree. Take note where the soil line starts. You will have to fill the remaining soil up to that line and not above.
7) Take off the pot and take a second or so to examine the root system. The soil falls off the roots. That is what we want. Mesquite trees live in sandy and rocky soil. Notice the tap root. It is runs across the broken part of the root ball. It moves from right to left. In this case, the tap root is the largest root in the pot and begins right under the stem of the tree.
8) In this case I’m forced to plant the tree right next to the pipe or it will not look right centered on the mow strip. See how the tap root it pulled out of the surrounding soil and stretched straight down. When soil is added to the root ball, it will be easier to anchor down the tap root to grow straight down.
9) Next is to dump your soil mixture to about half way up the hole. At this time, it is important to add the right fungi and bacteria to the project. I have placed several pinches of Rhizobium bacteria and Azosbacteraceae into the hole. It’s the white powder. Rhizobium is black and grainy. You can buy both bacterium in most larger hydroponic stores.
10) Finish topping the hole with the remaining soil.
11)You’re done. Later, I placed a thin layer of pea stones to make the area around the tree more uniform, but that is not necessary. Water the tree if is appears dry. In the next few weeks you will see the leaves of the tree fold together to conserve water during the day. In the evening and night, the leaves relax. Not to worry.
Since the Mesquite tree comes from another part of the South West, the local soil may not have all of the microbiology needed to sustain the tree. I have seen Mesquite trees grow in the Bay Area, but they are far and few in between. I’m guessing the winter frost will get it before the clay soil makes trouble. However, the tree still needs its own soil.
In any case, here is how to add the soil microbiology from Arizona into the Bay Area. I took a handful of soil from the area where this tree grows. Placed in a plastic bag and made an extraction tea out of the soil. This is different than compost tea. Compost tea is made of compost. The foreign soil is not compost, but soil. The number of microorganisms contained in the soil sample is many times less than compost. This means, it needs to be fed with more food and for a longer time. The point is to cultivate the soil’s micro biology and give it back to the Mesquite tree’s roots.
The recipe I used for this soil sample is as follow:
After cleaning everything and heating the water, I added the food for the soil to eat. Since it is soil, not compost, the cultivation period is a lot longer. If this is compost, the whole batch would be done in 18 hours. In this case, I let the batch run for 72 hours. Below are pictures of the microbiology of the soil extraction and cultivation. It his high in protozoan and in soil aggregate. There are a number of micro arthropods. A large number of fungi germinated from spores. This shocked me because Arizona does not strike me as a place where mushrooms grow. Last, the whole mixture is purred onto the Mesquite drip line. In this case, I placed all 4 gallons into the hole/filled soil are of the tree.