Tomato Fertilizer

Jason- I've been looking for your recommended 10-55-70 fertilizer -- do you have a source for it? My indoor tomatoes are not blooming!!! Thanks, Debbie.

Answer Debbie- on my tomato growing page I mention 10-55-70 fertilizer only as an example. The important thing to keep in mind when picking out a fertilizer is the ratio of Nitrogen to Phosphorus to Potassium, which make up the N-P-K numbers on a fertilizer. When tomatoes are ready to bloom, they require less Nitrogen and more Phosphorus and Potassium (especially more Phosphorus). Any of the following fertilizers, or fertilizers with similar ratios, would do fine: 10-20-20,   5-15-15,  15-30-20,  1-3-2,  or  12-24-15.

Again, these are just random examples. When using fertilizers with higher numbers, it will require less fertilizer to reach a particular fertilizer strength. When using fertilizers with low numbers, it will require a little more to reach a particular fertilizer strength. The important thing is the ratio of nutrients.....when you go to the store to purchase fertilizer, you will find that most "bloom" or "flower" formulas fall nicely within these rough guidelines.

In your question you mention your tomatoes are not blooming. It is very possible your problem has nothing to do with fertilizer. Outdoors, the main factor responsible for flowering/fruiting is darkness (lack of light). As the days get shorter and nights get longer, light-sensitive hormones (in most plants) detect these changes and trigger the plants to stop growing vegetatively and to begin flowering/fruiting.

So, the key to producing veggies on many plants is to first grow them to a reasonable (or mature) size vegetatively, than begin giving them 12 hours of uninterrupted darkness every night, at the same time night after night (a digital timer is very useful for this). This is known as flower forcing, and you can learn more about the process on my page how to force flowering.

My gut instinct tells me this is most likely your problem....even when given a vegetative stage fertilizer, tomato plants will still bloom if they are receiving a 12 hour dark period every day. So, make sure your tomato plants are receiving a period of complete darkness every night, and within about two weeks you should see tomato flowers begin to develop. I hope this helps!

Comments for Tomato Fertilizer

Average Rating starstarstarstarstar

Click here to add your own comments

Dec 14, 2009
response to tomatoes blooming
by: Anonymous

Thanks so much -- my tomatoes have not been getting 12 hours of darkness, so I'm sure you're right!!


Click here to add your own comments

Join in and write your own page! It's easy to do. How? Simply click here to return to Hydroponic Nutrients Q&A.

All of the items that I personally use and recommend!

AffordableGarden Design&Setup

(10 week update below)

Find out the cheapest and easiest ways to garden productively in this article.

Hi everyone, Jason from Jason's Indoor Guide here. When I got started with hydroponic gardening more than 24 years ago, my first garden used rockwool cubes and B.C. Nutrients....and I remember thinking to myself yeah, sure, there may be a lot of advantages to gardening with hydroponics, for example there are very few pest problems, therefore very little pest control, no weeding, no plowing or tilling the soil, no soil testing or having to add things into the garden soil, no watering the garden....but for someone who just wants to grow their own vegetables and have more control over their food supply and the quality of the food that they eat, the cost of constantly having to buy grow media and hydroponic nutrients makes this an expensive hobby for most people...

Epic Nutrient Change

I suppose when you take into consideration how much money you save NOT having to buy food at the grocery store, it is surely cheaper to grow your own food hydroponically even with the cost of high quality nutrients. Nevertheless, I didn't have a whole lot of money to work with and I needed to make my efforts as affordable and effective as possible....and in the last 24 years I HAVE learned a thing or two!

As you browse through Jason's Indoor Guide, you will notice all of the systems that I use personally are homemade systems. As I got 3 or 4 years of experience under my belt, I quickly adopted a preference to standing water systems and systems that use expanded clay pellets or lava rock, because the media is re-usable and it eliminates a huge operating expense. So once a hydroponic system is built, garden maintenance is minimal- check and adjust the nutrient solution daily, and to change it completely every 2 weeks....and the biggest operating cost is the hydroponic nutrients. (and the electric bill, lol)...

Homemade Cloner

And, regarding the cost of the nutrients....I experimented for about 3 years with making different compost teas and nutrient teas, but there is still a lot of expense $$$ associated with making high quality nutrient kelp meal, liquid seaweed, rock dust, bat guano, un-Sulfured molasses, worm castings. You can eliminate a lot of this expense by becoming an expert at making high-quality colloidal humus compost, and use your properly made compost as the basis of your hydroponic nutrient solution.

Unfortunately, I have been gardening for over 24 years and I have only just recently mastered this difficult skill....and even then, only because I happened to find a very easy to follow, high quality technique and decided to follow the instructions to the letter. I produced more high quality compost in just one week than I was able to use in a whole year! If you can master the technique, I highly recommend it. It is one of the top 3 things you can do to increase the productivity of your food production efforts, while at the same time decreasing the amount of effort required to grow all of your own food, and decreasing the total cost of operating your food production system.

And when I say decrease operating costs, I mean decrease them to almost ZERO, especially if you are producing your own nutrients...

High Efficiency

The ultimate solution to eliminate the cost of your hydroponic nutrients: Imagine a hydroponic system that does not require you to buy any nutrients, does not require you to make your own compost, and does not require you to brew your own nutrient tea. Seriously! No cost and no effort as far as providing nutrients to your plants! Plus, at the end of the gardening cycle you harvest all of your garden vegetables, PLUS YOU HARVEST FISH from the system--->


Click Here to learn more!

This solution is aquaponics. If you are serious about producing all of your own food and being self-sufficient, this is the ultimate solution for reducing expenses (as much as possible), reducing the total amount of work required, and maximizing the productivity of your gardening efforts. I have been gardening for over 24 years, and it is the perfect food production solution in my opinion.

Produce garnden vegetables AND fish together. Eliminate fertilizer costs!

Besides mastering how to make high quality compost, learning aquaponics is one of the top 3 things you can do to increase your garden productivity, reduce your total costs, and reduce your total work. The product that I learned from is called Aquaponics4you. With all of my hydroponic gardening experience, the first time I came across the Aquaponics4you product I knew immediately that it was something very special! Place an aquaponics system outdoors and use the sun instead of grow lights, and you have reduced every garden expense to nearly ZERO!

The Same System/ 10 Weeks Later!

If you've found this site helpful at all, I would really appreciate it