We recently moved into our first home, and we live in Las Vegas, NV (i think our hardiness zone is 8b). There is a raised bed along the back of the property, and I've cleared out half, have decided i want to use a clay pot/olla subirrigation system for water conservation purposes, but the soil needs a LOT of work before i can plant anything. I'm sure the easiest and cheapest thing would be to put lots of organic matter into the soil and till it, but I would like to get one harvest of herbs before our very short winter/frost season (late dec and january). I grew up in central IL where the ground is near perfect and hardly needs ANY work to grow herbs and veggies, so I need some help.
I have *never* seen an earthworm in any of the dirt in my yard, and the dirt is nearly white. I'm fairly certain it is very alkaline. From my understanding, some medicinal herbs prefer an alkaline environment, but still I can't imagine much of anything growing well in this dirt. It's hard as a rock, like trying to dig through cement, and when it is wet it literally feels like wet cement.
The area, if i did the math properly, is about 500 sq ft, and there's about 2 inches depth left in the bed after i removed all the rock. I'm not sure what type of top soil, or gardening soil I should get, or if i should just get "soil amendments" to add to it, and if so which ones and how much. With the bags of top soil and garden soil being about $2 per cubic foot, if i did the math right the cost would be insanely high just to get the soil fertile. Funds are limited but I am also wanting to do this as quickly as possible; I am really hoping to harvest some red clover asap for my daughter's health needs.
Any suggestions? especially if you've already done gardening in las vegas or other hot desert climates. Thanks!
I would not try tilling.
Is this surrounding new construction (or newish?)? It's very likely this is the result of the construction, though the natural state of the soil contributed to what you are seeing. The soil sounds high in clay. Where I grew up in East Las Vegas, the soil was extremely well-drained and the garden practically grew itself (just add water!)
Normally, you could just add your new soil in raised beds on top of this, but depending on what you are growing, that hardpan might create a barrier for water penetrating deeper. Have you tried seeing how many inches this soil goes down?
Clay soils are extremely rich, generally and, yes, soils in the desert will stray to the alkaline side, but possibly not too far. You could test to see what kind of alkalinity you are dealing with, but I wouldn't worry unless it seems extreme. For growing herbs, the soil mix to bring in should also be fairly lean.
I wouldn't sweat the lack of earthworms. Earthworms feed on organic material and, whether well-drained like the soil at my home or clay like yours, there is just not enough organic matter in the native soil to support an earthworm population until you are actively gardening.
I know there is better information about working with hardpan in the deserts, but I thought I'd put down the little I know to give this thread a bump. Gardening in Vegas is wonderful. You get excellent sun, but you also get low winter temps that some fruit trees require. The soil is lacking tilth, but is rich in minerals. In our garden, we pretty much just added water and things exploded!
The biggest problem that I see with this soil is that water will pool badly at the op of this layer and not penetrate, preventing planting larger trees and shrubs. Permaculture might have some solutions for you, and I know that groups are extremely active in places like NM, and they might have info available online for working with caliche and other hardpan soils.
Alright, that's my lame attempt to help!
Give me a few minutes while I caffeinate.
Looks like you have a permaculture organization in Vegas:
Quite a few people in my area that have hard soil plant by lasagna gardening (no digging, no tilling). Some areas here have a lot of caliche and are difficult to dig. If you want to get something in quickly you can plant in bags of compost. Just cut holes in the bag, plant seeds or starts, and water.
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