I have been hoping someone else would take a stab at your questions as I really don't know.

I get tripped up when you say Miracle Grow potting soil has stayed too wet, but other mixes haven't. In my experience Miracle Grow potting mix is pretty much interchangable with any other peat based potting mix as far as water retention/drainage is concerned so I am unable to understand why Miracle Grow stands out in your mind as 'bog-like' in it's water retention.

I also do not find that tomatos like lots of water. Sure, they do like moisture, but not excessively so.

Earthboxes, as I understand them, are simply a patented version of 'self' watering containers. All self watering containers suck and are terrific at the same time. Self watering containers are a great way to over water and they are a great way to not have to hand water every day ;-)

Think of a houseplant in a pot that has an attached drip tray under it. Water the plant too much and the drip tray fills with water. Repeat this long enough and most plants rot. This is all there is to most self watering planters.

During hot, dry summers this can work well, during cool wet times this can kill plants. I don't think potting mix has much to do with it if we are comparing one peat based mix to another.

Of course, I did say initially I wish someone else would have responded first because I don't have any answers to your query, just observations that may or may not be accurate or relevant ;-)

Since I have posted though, now others will feel more free to chime in and not feel as inadequent to address your question as I am ;-)

I'm bet the high humidity inside the GH, combined with a lack of direct sun & wind, has made the difference in the way the potting soil behaves. Out of 13 e-boxes the only 2 that are soggy are the 2 with the Miracle Grow. As soon as the veggies in those 2 boxes are done I'm going to pull out the Miracle Grow & use it in the containers on my deck. Those containers dry out way too fast & the Miracle Grow should be perfect in them.

An added benefit with the self watering e-boxes is that the tiny tree frogs hang out in the water resevoir. When my pond dried up the frogs moved into the GH & stayed all summer. During the day they climb up into the plants looking for bugs. It's great!! They are so cute!

I usually don't get too involved in EB discussions, but maybe I can help a little here.

Sorry Carolyn, but the 3 things that affect soil saturation in an earth box is how strong the capillary pull of the soil is (this will be controlled by the size of the particles in the soil and the size and number of macro-pores), where the false bottom is located in relationship to the level of the perched water table (PWT) and depth of water in the reservoir.

Earth boxes work by using a wick to lower the PWT in a container. The principle of wicking I frequently describe is the same as the principle used in earth boxes. The soil in the recesses in the box that contact the water are a wick.

First, the soils almost all of you use supports a (PWT). Imagine a 5 gallon bucket with a hole in the bottom, hanging by it's handle. If you water it from either the top or bottom, it will support perched water. Let's arbitrarily assign a 4 inch column of perched water that will not drain from the container. It sits at the bottom of the container & occupies all the pore space. Now, attach a 3 inch deep cup or funnel to the bottom that is filled with soil so that the soil is continuous between the two containers. What happens? The soil in the containers will only support a 4 inch PWT, so three inches of the water in the large container moves down and out of the small, attached container, leaving a 1" PWT in the large container. Increase the depth of the small container to 4 inches, and all the water in the PWT in the large container is removed and the 4 inches of soil in the small container is completely saturated.

Now imagine that this small container is the soil that is situated below the false bottom of an earth box and is in contact with the bottom of the earth box container. Given the seemingly perfect situation with a 4 inch PWT and a 4 inch container below the false bottom, there will be no saturated soil above the false bottom. However, if you add an inch of water to the reservoir, an inch of water will move up to occupy the inch of soil immediately above the false bottom. 2 inches = 2 inches above and so on.

If Carolyn's soil supports a PWT higher than the false bottom in the container, there will be saturated soil above the false bottom. The remedy is to raise the level of the false bottom, or amend the soil, adding more large pore space so the capillary pull is decreased, lowering the level of the PWT. The latter can be difficult and results less than good in soils composed of small particles.

Got all that? ;o)

Al

Al and CarolynA
I was told recently to find a soil you like to work with and learn how to water that soil for different plants. Almost any soil will work Its the watering thats important.
please comment.

There's no doubt there is a correlation between watering habits, drainage, and plant health. An open soil takes some of the pressure of the new or inexperienced container gardener by making it more difficult to over-water. More experienced gardeners who have a better handle on watering technique are better able to deal with a soil that drains more slowly and holds more water.

Will almost any soil work? I can't say yes, because there are limits to what soils even the most accomplished container gardeners can work with. There are some soils, fresh from the bag, that hold too much water and too little air to have plants grow with good vitality. Things are often complicated because new gardeners are unable to determine what a good soil is.

So, if you start with an average soil, the more it moves to the open, fast-draining side, the closer you can come to saying "any soil" will do. As you move to the other side, slower draining, less aeration, and holding more water, the closer I come to saying no, not "any soil" will do. Mix in watering habits & cultural condition changes & the case is made for an open soil being easier to grow in and healthier for the plants. The trade-off or price paid is the extra effort put forth in extra watering of regular containers. In earth boxes it makes nearly no difference in how often you need water.

Learning to water is more of a fine art than container gardeners realize until they're well on the way to understanding it. There are many stories of men and women, devoted to the art of bonsai and who have practiced it for years, who apply for an apprenticeship under a Japanese master. Accepted, they travel to Japan, where they pay for the privilege to work like slaves, only to find out that the first 6 months to a year or more is spent learning to water all over again under the watchful eye of the master. Only after learning to water to the satisfaction of the master are they allowed to work on the nursery trees.

Al

He also said for pines he would add more grit to his soil. So overall he probable agrees with you and adjust his mix but only for certain plants.
Paul

I grow some pines in a soil with no organic material. Some are in a soil with 10-15% organic component. All pines require good drainage & careful watering to grow at their potential vigor.

Al