How it looks from my perspective: If the decision to reuse container soils is an economic one, who can disagree with the decision? If you aren't concerned about expense and are willing to go to some minimal extra effort to build a good soil, that is what I would elect to do. Here's why: Container gardeners need to direct primary focus to insuring that the soil they are using will remain able to provide adequate air to roots for the expected life of the planting. Along with the ability of the soil to hold ample air, comes good gas exchange and drainage for rootage. All the other major cultural variables affecting growth are easily manipulated. Water, nutrients, sunlight, and to some degree, temperature can all be controlled easily. Aeration cannot and its consideration is as important as water and light to plant vitality. The breakdown or collapse of soil structure occurs at an exponential rate. If we imagine the usable life of a peat based container soil from a bag, it deteriorates from a reasonably good soil when fresh to unusable after 2 years. It's not unreasonable to expect the soil to lose at least 20-25% of its air holding ability by the end of the first growing season. In the first half of the second growing season, it will lose about another 25% of its air holding ability and in the second half of the second year, near total collapse is likely as the remaining 50% is lost. Though this is an example of an imaginary soil, it is very close to what actually occurs. Another way of saying it is: Even though a soil might be performing acceptably at the end of the first growing season, you should expect a rapidly accelerating collapse in the subsequent year. So, if you use a soil for 1 year and mix it 50/50 with a fresh, similar soil, 50% of the soil will have totally collapsed by the end of the growing season, and the other 50% will have lost about 25% of its ability to hold air. If a soil is not holding enough air, it's holding too much water. Water and air retention vary inversely in soils and when one increases, the other decreases. When soils hold too much water, you have to hope that the plant will use enough water or that enough water evaporates to prevent root rot issues and even minor cases of over-potting can mean terminal misfortune. At risk, I speak out often against the use of compost in container soils. It supplies nearly nothing in nutrients and clogs the soil macro-pores container gardeners should covet. Containers are not gardens and much of what works in the garden can cause difficulties in containers. Additional possible considerations are carry-over of fungal spores, the possibility/probability of insects in various stages (eggs, larvae, etc) and carbonate precipitates from your watering water. A slow soil will also have accumulated fertilizer salts and possibly insecticides that you may have applied and forgotten about last season. I suggest that container soils be turned into the compost pile or garden and fresh soil used in its place unless monetary considerations prohibit. Al

Hello, Our favorite tomato expert Carolyn137 wrote an excellent response to a question about Blossom End Rot (BER) and I am quoting it here: With BER there is NO problem with absorption of Ca++ though the roots. The problem is maldistribution within the plant that can be induced by a number of stresses which include uneven delivery of water, too much N, growing in too rich soil, too hot, too cold, too wet, too dry you name it. As the plants mature they can better handle the streses that can induce BER so usually it goes away. The two exceptions are first, if the soil has NO Ca++ as confirmed with a soil test, and that's a rare condition, and second, if the soil is too acidic in which Case Ca++ is bound in the soil. Again, adding lime, egg shells and on and on can not and will not prevent BER b'c absorption of Ca++ thru the roots is OK. Paste tomatoes are especially susceptible to BER and I think someone in a post above mentioned that. If you go to the top of this first page and click on the FAQ link and scroll down you'll also find an article about BER in case some of you have never looked at the FAQ's And there';s some darn good articles there as well, but I wouldn't pay any attention to the variety list b'c it's way out of date. The old information about BER being caused solely by lack of soil Ca++ has been shown to be wrong with research that's been done in the last 20 years or so, but it's going to take another generation before the real story gets into books, websites, magazines, etc. Most of the better websites already have the correct information. BER affects not only tomatoes, but peppers, squash, cabbage, cauliflower, etc., and it's a huge multimillion dollar problem for the industry, which is WHY all that reasearch was done. For instance, when tissues were taken from a plant that has BER fruits and was assayed for Ca++, the normal level of Ca++ was found, it just wasn't getting to the blossom end of fruits. And there's also a condition called internal BER where the fruits look fine, no evidence of BER externally, but when you cut open the fruit the inside is black Hope that helps Carolyn knows tomatoes! Betsy

If you really want to educate yourself, just start reading some of the questions and replies here. I don't mean to be abrupt, just saying that it is extremely informative. However, I will say that the most commonly recommended growing medium here is half commercial cactus and succulent soil and half perlite, both available at most nurseries. Strain the small bits of perlite out before mixing with the C/S soil. You can rinse it through a strainer. Don't breathe it. If you have a choice of C/S soils, look for the ingredients and choose one with no peat, if possible. As far as repotting after purchasing, just remember these plants do not like to be in oversized pots, just a little room around the sides and at the bottom is fine. Don't pot too low, clay pots are a good choice but plastic is ok too, and whatever you choose it MUST have a drainage hole in the bottom.

Technically, there is nothing you can add to Dr Earth soil to appreciably increase aeration or make it drain better. The reason is, even if you added an equal measure of pine bark or perlite to the mix so the ratio was 1:1, it wouldn't appreciably change the characteristics of drainage or aeration. The reason is, when you have an equal measure of coarse material and fine material, there will always be enough fine material to surround the large particles entirely, filling in ALL the potential large soil pores between the large particles with fine material. So, where is the improved drainage and aeration supposed to come from? Once the largest fraction of your soil is coarse material, you're technically amending the coarse material with the finer Dr Earth product, and not amending Dr Earth with say pine bark of perlite. I just talked about this on another thread where I mentioned the "threshold proportion". Simply put, it states that aeration/drainage can't increase unless there is a large fraction of coarse material AND an insufficient volume of fine material (Dr Earth) to fill in the potential air space between the large particles. So, if you want increased aeration and drainage, START with a volume of about 75% coarse material over .1" in size, and add only enough fine material (Dr Earth/peat/compost) to bring water retention up to something you can live with. In my experience, you can skip the EW castings and rock dust. They provide nothing that can't be had from a high quality soluble fertilizer like Foliage-Pro 9-3-6, which won't add sludge to your soil. Getting excellent nutrition to your plants is so remarkably easy there is no reason to concern yourself with container media's ability to feed the plant. You can do that and have excellent control over what, how much, and when plants get what they need in the way of nutrition; which means that focusing on the soil's ability to feed the plant instead of its structure and ability to retain that structure over the long term doesn't make good sense. What proportions of bark, Dr Earth, and perlite will work best depends primarily on the bark size. The best bark for 5:1:1 has an extremely high % of particles in the 1/8-3/8 size range. IF you had bark like that, you would START with a large fraction of that, then add a very small fractio9n of Dr Earth and some perlite to come up with a mix that has significantly better drainage and air porosity than your Dr Earth product. You would also need to add a small fraction of garden lime to the mix when you make it for best results. So for best results and the easiest path to success, container media need to provide a structure that can make root systems happy while the grower feeds the plant. Also, the soil you choose holds significant sway over how effectively you'll be able to hold up your end of the nutritional equation. Media that allow you to flush the soil at will w/o penalizing the plant make nutritional supplementation so easy you could train a monkey to do it. Al