Need advice for fertilizing tomatoes in pots

[Mike S.]

This will be my second year of growing tomatoes in 5 gallon pots. Last year I think I did pretty darn good considering it was my first year, the weather was unstable, and I have a black thumb (I'm so bad at gardening I even kill grass).

I think last year my biggest mistakes were not using a good fertilizer (I used imitation Miracle Gro) and lack of calcium. That and those pesky hornworms that ate two out of three of my tomato plants (I really hate those creepy little things).

I live in a small town and it's very difficult to buy fertilizers unless you want to get something in bulk, which I don't. I think I can get Bone Meal at a local store and I have some imitation Miracle Gro. Other than that, there's not really much available.

My plan was to mix the potting soil and Bone Meal when I plant the tomatoes, but how much Bone Meal should I add?

After that, how often should I feed the tomatoes? And what can I use? Like I said before, I limited in choices and I know I can get Miracle Gro and maybe Bone Meal. I may be able to get Fish Emulsion, but what kind of store typically sells that?

Will the Bone Meal and possibly Fish Emulsion be good enough for fertilizing? And will they provide enough calcium? I'm assuming Miracle Gro is a poor choice of tomato fertilizer, correct?

[Frank]

I use limestone and regular garden fertilizer bought in 40 lb bags. Maybe too much for you but both combined are only about $10 and will last for years. Last years crop was not that great so this year I've changed dirt. I use cheapest bagged top soil. Too much fertilizer too early has done in a few of my seedlings in the past so I don't fertilize heavily until there is a lot of growth. I find calcium and water are most important to stave off blossom end rot.

Frank

[William Rose]

Mike, Set up good conditions, plant and, keep soil humid, not soggy. The three numbers on the fertilizer e.g. 5-2-2 stand for 6% nitrogen, 2% phosphorous and, 2% potassium, respectively.

Nitrogen: Promotes leafy growth and green colour; organic sources are blood meal, fishmeal

Phosphorus: Aids root health and seed development; organic sources are bone meal, rock phosphates

Potassium: For strong stems and roots, proper water balance and disease resistance; organic sources are kelp and wood ash.

5-2-2 is about what you would expect from fish emulsion. Fish emulsion is good because it is nearly foolproof. In gardening, it is easy to kill out of kindness because we want to give the plant everything that it needs and we end up giving too much. Just follow the instructions. If anything, the manufacturer will have you using the maximum required, so that you will hurry back to buy some more.

If used according to instructions, the imitation Miracle Gro should be OK for the plants. (If you were growing in the ground there would be another long conversation about stewardship of the soil and your responsibility to life on Earth but, we can save that for another time because you are growing in pots, I presume with potting soil. The medium is the message.)

Nitrogen is good early in the season because it encourages vegetative growth but once up, you will want to cut back on it because you want flowering and fruit development.

I find it usually takes me about three time at doing something new to get the hang of it, so don't beat yourself up if you gaff it.

You may want to plant some basil as well. Nothing goes together better than popping a fresh tomato wrapped in a basil leaf into your mouth. That's livin'

Good luck, - Bill Coloribus gustibus non disputatum (mostly)

[Kay Lancaster]

Hornworms can be hand-picked, so that's a fairly easy fix for that. I assume your "lack of calcium" showed up as blossom end rot? If so, the bigger problem is actually uneven watering. A small drip irrigation system would probably be a better choice (and bigger than 5 gallon containers, if possible.) Mulch the top surface of the soil with several inches of clean grass clippings from a lawn that has not been treated with weed killers -- that will also help even out the water availability to the plants.

As to fertilizer... you need to read the numbers on the label, not the name of the maker. The order of numbers is N-P-K -- a higher first number in relationship to the others promotes vegetative growth, at the expense of root and flower (and fruit) development. Generally something with ratios of about 1:2:2 or 1:2:4 or 1:4:2 or 1:4:4 is suitable for tomatoes. Follow the package instructions as to amounts. However, my own preference when using highly soluble fertilizers like Peters' or Miracle Grow, is to use 1/4 the advised "monthly amount" weekly, properly diluted in water. If you start seeing salt crusts on the soil or leaf tip burning, you're using too much too often. Back off on the fertilizer and leach the soil with extra water -- multiple gallons running out the bottom of the pot. You might also choose a long-release fertilizer like Osmocote, mix it in with the soil, and be mostly done with it.

Or you can use various organic fertilizers -- just know that the ratio is the important part.

Watch the soil pH, too.

[Dave]

I tried a raised bed garden. 10X10. Last year, used potting soil and 1-2-2 ratio fertilizer. Didn't fare that well. May have been the hot weather, no rain.

This year, added 4" more depth. Used sandy loam, and a little pine bark mulch, with the same 1-2-2 ratio fertilizer. All mixed with last years stuff. 2 better boys are sprouting flowers already. Think I'm in trouble cuz I've got 12 going. 6 big boys/6 better boys. They did have leaf trouble for awhile, some kind of blight. All but one is over it.

Maters seem to like feast and famine with water here. They seem to fight back if I don't keep them wet everyday. Otherwise, mostly just lay there if I do. Guessing its promoting root growth.

[William Rose]

Try fish emulsion until they are a couple of feet tall, then go back to the 1-2-2. The ground needs to be dry on top and moist below, not soggy. Maybe try some black plastic around them to warm them up.

- Bill Coloribus gustibus non disputatum (mostly)

[jangchub]

When I plant my tomatoes in the containers I use half potting mix, half finished compost (no animal products in the compost)

I then mix in a slow release organic fertilizer with the ration of

8-2-4 which is also 4-1-2 etc. Certified organic fertilizer is much better than synthetic fertilizer because it feeds the soil as well as the plant and in turn gives a buffer against problems with lack of calcium, etc. However, after about a month in the container I use powdered skim milk mixed with the proper ratio of water and water the tomato plants with that and it is enough calcium. You can also use crushed up Tums or equivalent. I wouldn't use limestone as that can also reduce the pH and tomatoes like it a little on the acid side or neutral.