Temperature retention vs materials & texture?
 

Just a musing post. This may turn out to be a broad and pointless and gets no replies.

I basically went and remixed all my containers yesterday with additional vermiculite because all of them were more compacted than they needed to be. In the end I got extra mixes from un-compacting.

I wondered does some materials retains heat better than other? Which type of consistency would distribute a more even temperature throughout and retains heat better (more compacted or more porous). And is more wet or less wet better for heat retention. Then there is the microbes activity that influences it.

Yes, I know how big the container is and the material it's made of makes difference as well. But just in general, I'm more interested in how the actual make up and texture of the mixes can influence it, or not all? Or maybe it makes so little difference that it doesn't matter compared to more impacting factors like the sun and the container itself.

Obviously you don't want something that overheats also, I have a feeling it was better for me to have added more aeration to my mixes.

Most of the mass in the media would come from its water content.

The optimum container is determined by the weather. Most greenhouse pots are black, because most greenhouse plants are started in the cold spring and need the heat the black plastic collects. But in very hot weather, I will have to set those pots in a shallow bin of water to keep the plant from overheating.

It's a great balancing act: porosity, water retention of the particular component, % compost (if at all), plastic bags vs fabric, HDPE vs clay, saucer underneath or no, drip irrigation/fertigation vs hand watering vs hydro vs subirrigation vs dry farming, mobility, color of container, mycorrhizae...+...

In my sun drenched part of the world with very little rain, a porous, well-aerated mix leads you down the BER path, so one has to increase the water holding capacity, yet keep it from going the anaerobic route.

I like a mix of peat, coco coir and a little vermiculite as the water holding components.

Drilling holes near the bottom 3 inches helps a lot too.

I'm considering adding zeolites for next season, as they are relatively cheap down here. And I'm definitely adding silver mulch.

As the contents settle and the biomass is transformed into pretty tomatoes, I add a couple of inches of mix that's heavy on the fine bark chips and peat moss. At season's end there's usually plenty of roots exploring the top.

Good luck coming up with the right mix for your temps.

maxjohnson, we (My adult son and I) are growing carrots in 5 gallon buckets this winter. He is growing carrots in three buckets. He used MG potting mix in one bucket and the other two have different amounts of Earthgro potting soil mixed in. The Earthgro is pretty dense and has sand as a major ingredient. He got his three buckets ready a week ago. So far, there is a 1F degree difference. The straight MG is slightly warmer.

For my part of the experiment, I went with one bucket of Pennington potting mix, one bucket of MG raised bed soil, and one 50/50 mix bucket. I just started yesterday and have not put a thermometer in it yet.

Neither of us has planted carrot seeds or fertilized yet. The ground/bucket soil temperature is still too hot. I am thinking that adding fertilizer could raise soil temperatures a little. I don't know, the experiment/s are just getting started.

I may have missed this from discussions in other posts, but what was your container mix before adding vermiculite. It is not something I would have thought of as a go to amendment for used soil. My routine for freshening containers is plain old leaves and bagged compost added in fall or early spring. I have a huge bag of vermiculite taking up garage space. Nice.

[QUOTE=maxjohnson;599823]Just a musing post. This may turn out to be a broad and pointless and gets no replies.

I basically went and remixed all my containers yesterday with additional vermiculite because all of them were more compacted than they needed to be. In the end I got extra mixes from un-compacting.

I wondered does some materials retains heat better than other? Which type of consistency would distribute a more even temperature throughout and retains heat better (more compacted or more porous). And is more wet or less wet better for heat retention. Then there is the microbes activity that influences it.

Yes, I know how big the container is and the material it's made of makes difference as well. But just in general, I'm more interested in how the actual make up and texture of the mixes can influence it, or not all? Or maybe it makes so little difference that it doesn't matter compared to more impacting factors like the sun and the container itself.

Obviously you don't want something that overheats also, I have a feeling it was better for me to have added more aeration to my mixes.[/QUOTE]

Vermiculite makes a nice seed-starting mix. It doesn't crust over on top like anything with peat in it. And an expensive seed starting mix like Light Warrior can be diluted a long way with vermiculite as well.

Cole, do you use light warrior for seed starting? If so do you add anything to it and what size containers do you employ?

Light Warrior is awesome. It's just so expensive, $20 a bag. I'd say it is worth it when sprouting very expensive hybrid seed. For everything else, I dilute it substantially with vermiculite, which I put in the bottom and on the top layer. I sprinkle a little of the Light Warrior around the seed itself. Any container works for sprouting. I have used six-pack cell trays as well as 4" pots. The key is the seed depth. You want it as shallow as you can keep it without it drying out, which is an answer that depends on your media and environment.

Another thing I like about vermiculite on top is that it is easy to see when it has dried out. There is no crust; it's like dry sand.

Thanks Cole, read your reply 5 times til it sunk in a little. Haven't seen the LW around here but saw it in Santa Barbara hydro shop when I was down there. I'll pick some up if I can hide the price tag from my wife lol. Do you add anything or fert or will it thrive til transplant? Thanks in advance for all the good info.

You're welcome. LW has worm castings in it, which is enough fertilizer for small plants.

[I]"Light Warrior is awesome."

[/I]Awesome is the word my hydroponics store guy uses for the FoxFarm Light Warrior. Says it's his biggest seller with experienced growers and these are people who plant $15 seeds. If I didn't have promixHP on hand, which I use and has microbes, I'd probably use the Light Warrior.

Thanks for the replies.

[QUOTE=greenthumbomaha;599921]I may have missed this from discussions in other posts, but what was your container mix before adding vermiculite. It is not something I would have thought of as a go to amendment for used soil. My routine for freshening containers is plain old leaves and bagged compost added in fall or early spring. I have a huge bag of vermiculite taking up garage space. Nice.[/QUOTE]

I actually used vermiculite because I cant figure out how to get very fine pine bark. I wonder if I can turn them to fine sizes by myself.

My container before simply had compost and Ecoscraps potting mix which has good amount of fine pine barks, but the ratio was wrong. Also, gasp..... potting soil, which I already know to not waste my money on.

Vermiculite us best as a moisture retainer. Perlite us for filler and root aeration.

Did I say $20 a bag for Light Warrior? Let's amend that statement. I just came home from the garden store, and it is now $35 a bag.

Yes, I just paid $35 for what looks like a bag of dirt. I feel like I traded a cow for magic beans.