Fertilizer and Potting Medium

I so wish I'd known more about fertilizer and potting medium before I began this little tomato growing adventure this season. It turns out that this is the most critical aspect of tomato growing. It can make all the difference between a prolific producer and an anemic one, assuming you have good growing conditions.

What kind of fertilizer do you use?

With fertilizer there are two main approaches you can take: store-bought and home-made. Store bought can be very expensive, depending upon your selection, and not necessarily make a dramatic difference. Home-made can be extremely cheap but also a bit time consuming, with mixed results. A lot of this will be dependent upon your choice of potting medium and frequency of application.

In my first endeavor, I made a slight mistake from the beginning.  I put my tomatoes in "top soil" instead of "potting mix". It is said that traditional soil will make moisture control problematic and the dirt will end up packing down, making the tomato roots work much harder to spread out. The only good thing is that the top soil I chose was nutrient rich, providing a good foundation of fertilizer. I really didn't do much else in the way of fertilization either, other than a couple dozes of plant food every couple of weeks.  I'd heard about how tomatoes need lots of calcium, so I crushed up a bunch of eggshells I'd saved and spread it in the soil bed where I put the plants.  I also sprinkled a lot in the top of the soil, mixing it in with the expectation that it would break down over time and provide the plant calcium throughout the growing season.

Next time, I'm doing it a bit differently!

First and foremost, I think it's a really good idea to leverage natural fertilizer as much as possible. This is the way plants normally get their nutrients to begin with, from organic matter that has been broken down. Compost is ideal... however, it does not necessarily provide the best combination of nutrients. Plus, it's rather inconvenient to prepare compost in an apartment situation. You can certainly buy it... but you won't really know for certain how good it is until you try it--worth risking a whole growing season? I wouldn't try it.  There is something to be said for commercially produced fertilizer from respectable sources. If you search the Internet enough you will find plenty of testimonies about various fertilizers and can then make your choice based on that (such as "Fertilizer Program -- Containerized Plants"). The trick is finding the right amount for a reasonable price.

Potting Medium

I've read quite a bit about potting mediums and there are so many opinions, so many choices that it's mind boggling. The best thing is to find someone growing a plant in the way you'd be doing it (size, material, location/region) and abide by their choices if they are presenting impressively positive testimonies. If money wasn't an issue, I would get Premier Pro-Mix HP Mycorrhizae. It is a potting medium highly regarded by professional growers. The only trouble is that the smallest size is 2.2cu-ft and the cheapest price I've found is $30 at Lowes. It might be worth getting and using in combination with another medium to extend it enough for planting needs across a couple of seasons.

Fertilizer Nutrients

Tomato plants need about 16 different nutrients, with 4 of them being essential.  The 4 primary nutrients are nitrogen, potassium, phosphorous, and calcium. You'll mostly see the first 3 referred together as N-P-K. I've read that the average ratio most plants require is 12:4:8. It just so happens that Miracle-Gro makes it, named as "All Purpose Liquid Plant Food" (analysis 12-4-8). You can get it quite cheaply through Amazon, a 32oz jug for just under $7. But is this recommended for tomatoes? Not really. From what I understand, their preferred nutrient ratio is a little different depending upon the growth stage. While nitrogen is essential for enabling absorption of other nutrients, too much can actually block absorption and incite the plant to produce more foliage rather than growing fruit.

For example:

Stage 1 --  First true leaves till plant is 14"-16" tall
N-100 ppm
P- 40 ppm
K-200 ppm

Stage 2 -- 14"-16" until 24" tall when first fruit set is 1/4" to 1/2" in diameter
N-130 ppm
P- 55 ppm
K-300 ppm

Stage 3 -- After fruit set till maturity
N-180 ppm
P- 65 ppm
K-400 ppm

So the highest ratio of nitrogen to potassium is in the first stage.  Then across the next two stages of the season, the amount of nitrogen is reduced.

But then you have commercial products like Scott's Miracle-Gro Tomato Plant Food providing an NPK ratio of 18-18-21 (or 6-6-7), while Tomato Tone provides 4-7-10 and others giving 10-15-10. What's really the right amount?

In my estimation, the availability of all essential nutrients is key. The issue is making sure that none of them are too scarce or too plentiful. The plant will draw upon what it needs. However, too much of certain nutrients can interfere with the uptake of other nutrients, causing toxicity or "fertilizer burn."  A little is better than none at all or too much. As long as some fertilization of the essential nutrients is provided, the plant should do well. Yet unless you find an optimal balance, you can't expect your tomato plant to be a prolific producer. Yes, it's easy to envy photos from other tomato growers showing massive tomatoes or copious clusters of them. But then, they have likely invested a significant amount of time finding their own optimal tomato growing techniques for their situation. My hope is to eventually find a good technique that I can reproduce year after year with very good tomato growing results--not necessarily the most optimal, but at least above average.