Tips for growing veggies in containers in a desert
I'm planning out my summer garden and trying some new things this year, so I'd love to get some advice from you all. I apologize that this will be long, but I'm trying to present everything here, rather than asking questions in multiple threads.
I've run out of in-ground gardening space, and would like to expand into containers. So far, I'm hoping to do poblano peppers in 5 gallon buckets and indeterminate tomatoes in 20 gallon storage tubs. I've read about the 511 mix, but because of the extra time and energy to find all the supplies, screen them correctly, and mix up a big batch, I'm considering that a last resort. If I can put in less effort, using bagged potting mixes with some amendments, and still get decent production, I'll be very happy. So far, I know not to get potting soil, or Miracle Grow Moisture Control.
I live in Riverside CA, where we don't get summer rain and temperatures exceed 90F for basically all of July, Aug & Sept. The extreme aridity and intense sun are making me nervous about container gardening.
If I need 50 gallons of growing media for two 5gal buckets and two 20gal tubs, that's ~7 ft3. Last year, I bought a bulk "Planting Mix" from a local nursery to build a raised bed, and it did very well. I've attached a picture of the dry mix, but based on what I've read here, it's probably not suitable for containers - too much 'dirt'.
Right now, my options seem to be:
Sunshine Mix #1 - $33. This comes in a 3.8 ft3 compressed bale, which I'm guessing should expand to almost enough volume. (I can also get Mixes #2-5, but don't know price.)
Sta-Green Potting Mix or Kelloggs Patio Plus Potting Mix - bagged at Lowes - probably around $30 for the total volume I need.
The Sunshine Mix is mostly peat based, with perlite and some fertilizers. The other two Potting Mixes are made of "composted forest products".
Generally speaking, I know that the advantage of the 511 is that it doesn't compact, doesn't retain excess water, and provides air to the roots, which makes the plant very happy. Given that I'm in a very hot, dry climate, though, I'm ok with sacrificing some of the plant's "potential" for the convenience of not having to water twice a day every day. I looked at Lowes and a local nursery, but haven't been able to find suitable bark fines yet, although I have seen perlite and I can continue searching for the bark if you think it's necessary.
Does anyone have any suggestions as to which media would work best in my conditions?
I'd also love some general container-growing advice. So far, I've heard about the following:
- Shade the pots with cardboard or wrap with white fabric to reduce the soil temperature
- Cover the foliage with shade cloth during summer heat
- Put string or strips of an old t-shirt through the bottom holes to allow excess moisture to wick out
- Don't put gravel in the bottom of the pot
- Water until some liquid comes out the bottom of the pot. But I've also read to water from the bottom with a tray. Aren't those exclusive?
- Mulch with straw
For fertilizers, I've read about using Osmocote for long term nutrition supplemented with weekly dilute waterings of MiracleGrow and "micronutrients" - what are micronutrients?
Any other advice for a newbie? Thanks very much.