Thanks Mike and nice to meet you too. Castiloga recommended that mixing perlite into the potting mix that I already have will help albeit a little. Should I start off with this? As for the sand that I found available at the local garden shop was the red type - looking like the builder sand - but it was not coarse enough (let alone very coarse). Is there some sort of measure to determine how much coarse the sand should be for potting mix purposes? I have found a picture of the red sand from the internet and thought this might help you in assessing what I am referring to. Also I found a very huge supply of tiny gravel (around 5mm) just lying scattered besides my apartment building in quite a large quantity. Can that be used for any purpose? By appropriately mixing it with the potting soil or sand etc? Will this be helpful in water flow and aeration? O and btw, the potting soil that I will now be using (my fourth try) is on the link provided below - has details about what fertlizer and PH it has. It also says it has 125% water retention ability!! Thanks again. Here is a link that might be useful: Al Bustan Potting Soil. This post was edited by saood on Wed, Oct 9, 13 at 2:51

An interesting experiment, but I'm worrying about something: water amounts and frequency. Are you going to water them with the same amounts at the same time, or will you only water when the containers are completely dry? The main purpose for different mixes is how they help control the length of time before the pot is dry again. They have a direct effect on frequency of watering. I use about 90% inorganics in my mix for potted plants that stay outside all winter long. A low organic mix is necessary because of the cold and wet winter conditions where I live. A mix that dries quickly is essential. I also like to err on the dry side during the rest of the year, since succulent plants tolerate that much better than prolonged wet conditions. However, many commercial growers like Altmans use a mix with lots of water retentive organics like peat, and the plants grow well in that when they are young. A mix higher in organics should theoretically increase growth rates. The size of the pots relative to the plant also plays a role here. I suppose you intend to compare growth rates in these different mixes. However, for this experiment to be meaningful, you would need to keep the watering regime the same for each of the pots. You could water from the bottom, and measure the amount of water the plants absorb at each watering. Or, you could use a moisture meter to measure substrate dryness, and record the length of time between completely wet to completely dry which should be different for each of your pots. Anyway, I like the idea and look forward to seeing what happens. You've already put a great deal of work into this experiment. I'm just not sure what sort of data should be measured. If you use a moisture meter, and water only when dry, you could measure the amount and frequency of water, and compare growth rates. But if you don't control the amount of water applied, a comparison of growth rates would be less meaningful. Brad

Stick your finger into the dirt and see if it is wet or not. Treat the plant like any other Draceana. They don't like to be continually damp. I have a Peace Lily in a "self watering" pot. Mine works by having a reservoir and wick. I don't use it that way technically, I over water the plant from the top so the excess runs into the reservoir and don't water again till the top of the soil just dries. The wick keeps the plant evenly moist till the reservoir runs dry and the plant dries somewhat before getting watered again. The reservoir doesn't stay full this way (as a matter of fact it never gets full either as I only let it get a little bit of excess run off. Maybe half a cup or a bit more. Not sure you could do the same. But you also don't have to use the spa but just water from the top like a regular houseplant.

H - from the snippet you've shared about yourself, I can see you'll move forward quickly. If you skip the years of trial end error that keep most growers tide to an anchor, learn how to best proceed, then use your practical experience to validate what you know instead of finding out what you don't know, you'll be amazed at what's possible. If you have established that the soil is completely dry, using the dowel rod method (I used a wooden pencil, which I hope is also okay), is it then always a good idea to water the plant? In a very high % of cases, it's best to water when moisture is barely detectable on the tell, but there are plenty of plants that need to be dry or almost completely dry during a portion of the growth cycle. No stress is good for plants, so if a plant should be actively growing, it's best to disallow them from going completely dry. There is sort of a built-in cush, however. When the soil feels dry to the touch, there is often still some residual moisture accessible to the plant. If you can see obvious signs of a plant being dry, it's too dry - again, unless you're adhering to a plan, the wisdom of which over-rides the rule of thumb. It seems to me that in the case of some succulents (notably cacti, but also other dry spell loving succulents) it would be advisable to keep the soil dry for some time, how would you assess how long the soil needs to stay dry? I think I should have read your entire paragraph before I started to reply. I sort of gave you a reply in what I said immediately above. The rest of the answer is - researching RELIABLE sources for care instructions re individual species would always trump general rules or rules of thumb, but for the most part, for plants other than cacti and a middling measure of succulents, watering just before they go dry will keep you in good stead. You talk a lot about the right potting soil in your posts. I often get my plants from the local super market, or my local nursery. How do I assess whether the potting soil they have used for their plants is correct? For greenhouses and nurseries, the soil that's correct for them is the soil that allows them to get their plants to their POS (point of sale) for a minimal outlay. Generally speaking hobby growers are unconsciously seeking the gratification we get from nurturing. We're willing to spend more time, effort, and $ to ensure our plants are healthy/happy so we get that gratification/personal satisfaction. A few days ago, I mentioned the relationship of greenhouse to the plants they sell is closer to the relationship between puppy mill and puppies than it would be to you or I and the plants we tend. Potting media run the gamut of suitability from virtually unusable to almost perfect. It's easy to make the case that a "good" soil would necessarily be one you don't have to battle for control of your plants' vitality. IOW, unless you can water correctly w/o having to worry your plants will suffer from extended periods of soil saturation, it's hard to say you're using a good soil. Things take a very sharp turn in favor of the grower when they understand the concept that allows them to control how much water their soil will or can hold. Where fertilizing containerized plants over the long term is quite difficult to get right when you can't water correctly, it's monkey-easy when you can. Getting past that whole 'water-retention/good or bad soil thing' is undoubtedly the biggest obstacle container gardeners will find in their path, no matter whether they ever realize it or not. How do you feel about submersion tactics for watering plants, since it seems to me that this would increase the amount of water the plant receives, while the PWT would stay on the same level? Submersion has it's place - mainly for plantings that have gone dry, and contain media that turn hydrophobic (water repellent) once the % of moisture in the soil drops below a certain point. I like watering from the top because it's more effective at flushing accumulating salts out of the soil. For any given soil that supports perched water, the maximum ht of the perched water table is a constant. No matter how large a container is or what shape it is, if the soil supports 4" of perched water, it will do that in every pot it's used in. It follows then, that no matter how you water, as long as you water to beyond the point of complete soil saturation, the ht of the PWT will be exactly the same at the point the pot has stopped draining (for a given soil). I was also wondering whether there are certain books on scientific ways of caring for plants that you would recommend for people eager to learn, or whether you have maybe wrote some more comprehensive guides in other places? I learned a lot from the Ball Publishing book "Water, Media, and Nutrition for Greenhouse Crops", from "Plant Production in Containers II" by C.E. Whitcomb, Ph,D, and from Growing Media for Ornamental Plants and Turf by Kevin Handreck & Neil Black. I don't know if you've read what I wrote about How Water Behaves in Soils, but it's a collection of information designed specifically to unburden growers of the limitations associated with overly water-retentive soils. There are also threads that describe work-arounds for those who can't or are unwilling to modify water-retentive soils to make them less limiting. Al