Planted my corn today in my homemade Earthbox. I can't wait to see it grow in to stalks, but I'm a little concerned about the quality of my homemade box. I picked up some containers that got bigger as they got taller, but I didn't realize it until I had already cut one. In order to make the one fit in to the other I had to cut some slits in the sides to give it some wiggle room. It seems okay though, I packed soil on top of the gaps on the sides in the hopes that nothing would fall through there. I guess I'll know how I did in 7-14 days when the seedlings are supposed to pop up :) I'm planning to grow tomatoes in my retail Earthbox when it arrives. I see what you guys mean about the potting mix with fertilizer, I bought a 3 cubic foot bag of Sta-Green potting mix today that says it's supposed to feed for 9 months, but the numbers were all decimals (.14-.11-.08), much lower than the recommended 5-15 range.

You might know some of this already, seysonn, but the super simple approach to fertilizing would be to premix up to 1 tbsp of controlled release fertilizer (Dynamite All Purpose Select, for example) per gallon of potting mix and then to apply a soluble fertilizer (Dyna-Gro Foliage Pro, for exampe) at every watering. In general, aim to provide the soluble fertilizer at label rate weekly (so if the recommended rate is 1 tsp per gallon you'd simply divide that by the number of waterings per week). The CRF provides a steady source of nutrients throughout the growing season (which is especially valuable in prolonged wet weather when you don't need to water), and the soluble fertilizer gives you some control over growth rates. If you want to slow down vegetative growth, for example, you can reduce or withhold the soluble fertilizer (or you can alter the NPK ratio with a supplementary product like Pro-TeKt, which can accomplish the same thing). This post was edited by shazaam on Sat, Nov 9, 13 at 10:50

Ox - I was doing some research, using the search function, when I came upon this thread and realized as I scrolled to the end that I never answered your question. Just saying that you use MG isn't enough information. MG manufactures several soluble ratios. 20-20-20, 24-8-16, 12-4-8, 10-30-10, 10-52-10, 30-10-10 are all soluble MG products. The ones most fig growers are apt to reach fore are 24-8-16 (best choice) or 20-20-20. Your assertion that you would be over-applying P is correct if you are using anything but 24-8-16, 12-4-8, or 30-10-10, and the latter is inappropriate for figs in containers because of its high N content in relation to the other macro-nutrients and it's acid reaction in the soil solution. If you ARE using either 24-8-16 or 12-4-8 (the same ratio - 24-8-16 simply contains more of the 3 primary macros by weight than 12-4-8) you are supplying P in almost exactly the correct ratio. The P in fertilizers is not reported as elemental P, instead, it's reported as P2O5 (phosphorous pentoxide - K is reported as K2O). To find out how much P is ACTUALLY in the soil, we need to use a factor of .43 for the middle number. When you multiply the P in 24-8-16, you get 8 x .43 = 3.5. Taking this 1 step further, and recalling that upthread I said that plants use about 6X more N than P, dividing the amount of N in 24-8-16 by the actual amount of P (24/3.5 = 6.8) we find that MG 24-8-16 has 6.8 times as much N as P. The amount of K similarly follows the amount of K in relation to N as being provided in almost exactly the same ratio in which plants use them. Some would have you believe there was no thought that went into deciding on the ratio fertilizer manufacturers chose as their 'all-purpose' fertilizer, but from these quick calculations you can see that they provide nutrients in as close to the ratio plants use as you'll find in any commercially available fertilizer. It was no accident. Now your questions about fertilizer phosphate: The phosphate in fertilizers is initially quite soluble and available. Most phosphate fertilizers have been manufactured by treating rock phosphate (the phosphate-bearing mineral that is mined) with an acid to make it more soluble. When the fertilizer or manure phosphate comes in contact with the soil, various reactions begin occurring that make the phosphate less soluble and less available. The rates and products of these reactions are dependent on such soil conditions as pH, moisture content, temperature, and the minerals already present in the soil. This chance to an insoluble form is MUCH less prevalent in container soils because of their relatively low bulk density and high organic content. As a particle of fertilizer comes in contact with the soil, moisture from the soil will begin dissolving the particle. Dissolving of the fertilizer increases the soluble phosphate in the soil solution around the particle and allows the dissolved phosphate to move a short distance away from the fertilizer particle. Movement is slow but may be increased by rainfall or irrigation water flowing through the soil. As phosphate ions in solution slowly migrate away from the fertilizer particle, most of the phosphate will react with the minerals within the soil. (Again, this is in MINERAL soils, and not so much in container media.) Phosphate ions generally react by adsorbing to soil particles or by combining with other elements in the soil, forming compounds that are solids. The adsorbed phosphate and the newly formed solids are relatively available to meet crop needs. Gradually reactions occur in which the adsorbed phosphate and the easily dissolved compounds of phosphate form more insoluble compounds that cause the phosphate to be become fixed and unavailable. Over time this results in a decrease in soil test P. A general sequence of reactions in alkaline soils is the formation of several compounds that result in a decrease in solubility and availability of phosphate. Each of these reactions will results in very insoluble compounds of phosphate that are generally not available to plants. Adding to the active P pool through fertilization will also increase the amount of fixed P. Depleting the active pool through crop uptake may cause some of the fixed P to slowly become active P. The conversion of available P to fixed P is partially the reason for the low efficiency of P fertilizers. Most of the P fertilizer applied to the soil will not be utilized by the crop in the first season. Continued application of more P than the crops utilize increases the fertility of the soil, but much of the added P becomes fixed and unavailable. An important aspect of the ability of a soil to hold phosphate is that a soil cannot hold increasing amounts of phosphate in the solid phase without also increasing soil solution phosphate, so there is sort of a threshold. Increased amounts of phosphate in solution will potentially cause more phosphate to be lost to leaching through the soil - especially in container soils, another very good reason not to over-apply P. You asked: "If we water to the point that our pots drain, would it be wise at some point to simply provide nitrogen alone?" I would give a qualified 'NO' to that question. For us hobby growers, I don't think it's ever a good idea to provide singular elements as a fertilizer unless it's part of a well-conceived plan. When you start second guessing what you're seeing in your plants ...... well, even the experts are often fooled and misdiagnose deficiencies and related problems. We might see yellowing leaves caused by a high level of soluble salts in the soil or over-watering and conclude the plants need N, which only exacerbates the issue. I don't think it is reasonable to apply urea and wait for other deficiencies to be revealed. I think that if you are absolutely sure that all other nutrients are in the soil at adequate levels and in the right ratio and N is the only element shown to be deficient, then applying urea would be the correct thing to do, but absent that knowledge, I would stick tightly to using a 3:1:2 ratio fertilizer and flushing the soil regularly so that ratio in the soil solution isn't skewed by accumulating salts. If you CAN'T flush the soil regularly w/o risking root rot, I would take a hard look at my soil choice and switch to a soil that DOES allow you to water that copiously. Sorry I missed this, Ox .... and sorry for the length of the reply. ;o)

Hi Tom, >>Im a little confused now about the Ingredients of the what they in the books call Solution A..With solution A they mean 1 of 2 components. You probably found out that you can't mix certain salts in concentrated form and hence need to split them in A and B. >>My Question: Mono Amoniac Phosphate and Potassium Phosphate Mono are the same? (I think not) Are both of this Nutrientsalts working good? If yes, are the concentrations the same?Both are not the same but very distinct ingredients/components. Hence the concentrations are different as well. Both are used to provide P (Phosphorus) and either N or K to the formula. Potassium Phosphate Mono is more commonly used, and Ammonium Phosphate-mono (or Mono-ammonium Phosphate) can only be used sparingly in a formula (added in small amounts) because it has 12.x parts of ammoniacal Nitrogen. Only a max of 15% ammoniacal Nitrogen can be added to a formula, because of it's relative "toxicity". I am not posting any formulas publicly (anymore) for professional reasons. But you can email me at chiliparadise(at)gmail.com anytime for more details and formulas. I am perfectly fluent in German and French, and I guess one of them should do fine for a swissman, right? ;-) If you want to go on your own instead, a standard lettuce formula (compared to others) is quite easy to get hold of with some more extensive googling. You mainly have two types 1. Higher in Nitrogen (in relation to K) for cooler climates and indoors, and 2. Somewhat higher in Potassium (compared to N) for hot-, summer or tropical climates. Any lettuce formula should do for basil, as basil thrives quite well with almost any formula.