Learning how to grow tomatoes indoors can be very rewarding. My own organically grown tomatoes always taste better than store bought ones. My mouth waters just thinking about my next fresh tomato salsa or the smell of garlicky homemade spaghetti sauce simmering. Mmm, let's get started!
Take your time picking out a great tomato variety to grow. Many hothouse growers make the mistake of choosing a fast growing tomato, then forcing the fast growth with chemical fertilizers. This is a profit driven strategy and usually produces tomatoes with very little flavor. If you want award winning flavor, I recommend using a proven heirloom variety fed with organic nutrients, and given plenty of time to ripen in a natural fashion.
The first step to learning how to grow tomatoes is preparing a good planting mix to start with. The mix I use is a standard soil-less potting mix with about 10% worm castings added. Standard potting mix is usually equal parts perlite, vermiculite, and sphagnum peat and is adjusted to the right pH by adding 1 teaspoon of hydrated lime for every gallon of soil mix. For tomatoes, I like to adjust the pH of my soil mix this way because the lime is a good source of Calcium (which prevents blossom end rot in the tomatoes later on).
Moisten the initial potting mix little by little, using plain water and Thrive Alive B1. The mix is just right when you squeeze a handful of the potting mix and get just a few drops out of it... but only a few. If your mix is a little too wet, just add a few handfuls of dry vermiculite (or perlite) and remix.
Starting seeds is always a delicate part of growing anything, and learning how to grow tomatoes is no different. Start with a regular nursery tray full of your soil mix. Tomato seeds should be planted 1/4 inch deep, and about 8 seeds/inch. You may want to cover them for the first few days to keep them from drying out. If your seed starting tray does not have a lid, a sheet of plastic wrap will do fine.
Tomato seeds germinate best at 80 degrees, and should be mostly up in 5 to 12 days. Remove any cover you may have on them as soon as they begin popping up. The fresh sprouts should be kept 4 to 6 inches from a fluorescent grow light. The light should be kept on 18 to 24 hours a day to encourage vegetative growth. When they are 1 1/2 inches tall, carefully transplant them into their own 6 inch containers.
This is the easiest step of how to grow tomatoes. Keep them under 2 or 3 fluorescent lights that are kept on 18 to 24 hours every day. I usually feed them Maxsea 16-16-16 at this point, although they could probably use even more nitrogen (the first number). The strength of the solution is about 600 ppm, which is 1 rounded teaspoon of Maxsea/gallon. I also add 10 ml/gallon Thrive Alive B1, which helps to maintain fast cell division and healthy growth.
If you are growing in a hydroponic system, the nutrient solution is being provided to your plants on a regular basis by the hydroponic system. If you are growing in the soil or in a soil-less mix, your plants should be watered with the nutrient solution (fertilized) every two to four weeks, depending on the feeding requirements of your particular plants.
I often like using Maxsea because it is a seaweed based fertilizer.
Seaweed is a rich source of trace (or micro) nutrients. As long as the
major nutrient requirements of your plants are met, there should be no
problems with any nutrient deficiencies....as long as a seaweed based
fertilizer is used. Another option is to use your favorite 3-part
hydroponic fertilizer, which would also provide all of the necessary
primary, secondary, and (in particular) micro-nutrients.
The ideal temperature for growth is 72-80 degrees during the day and 65-70 degrees at night. When the plants reach 12 inches or more, they may need transplanting into one gallon containers. After 6 to 8 weeks, your plants should be just about ready to begin bearing fruit.
Flowering is one of the trickiest parts of how to grow tomatoes indoors. You will need to be familiar with how to force flowering
in your plants. Some tomatoes produce fruit in 60 days and others take
up to 80 days, beginning from the time you force flowering. Some time before this point you want to make your final transplant into 3 gallon containers. Do this about two weeks before you force the flowering cycle to give your tomato plants time to adjust before fruiting.
For the first two weeks, you want to continue feeding them with a balanced N-P-K fertilizer like 16-16-16 or similar. After the first two weeks of flowering, the fertilizer should be adjusted to contain less Nitrogen and more Phosphorus and Potassium. A fertilizer like MaxSea 10-20-20 would be appropriate for the rest of the growing cycle. Each time they need water give them fertilizer also at 800 ppm, which would be about 2/3 of the recommended "full strength" found in the MaxSea fertilizer directions. Keep in mind you are feeding them each time you water them. For the rest of the season, feed them 10-20-20 or similar at 800 ppm.
Flowering is the trickiest part of how to grow tomatoes (indoors), and pollination is the trickiest part of flowering. As soon as flowers develop and begin to open, you must pollinate everyday while it is warm and humid. Ideally, the humidity will be 65 to 70 percent. Greenhouse growers usually do this between 11:30am and 12:30pm (basically noon) when these conditions occur naturally. For them, early and late day pollination often will not produce proper crops.
This is a tomato flower. Part A is the male anthers that will drop the pollen. Part B is the female carpels that will catch the pollen. The little red arrow is where it all takes place.
Most male anthers produce their pollen on the outsides of the anthers, making it easy to release pollen into the wind for pollination. In the tomato plant, however, pollen is produced internally, as if trapped in a straw. This is the biggest problem for indoor tomato producers just learning how to grow tomatoes indoors.
The plant needs vibration at the right frequency, such as the buzzing of a bees wings, to dislodge and release the pollen. Large greenhouse growers often use mason bees, located in small boxes inside the greenhouse, to do this efficiently. Small growers often end up doing the work of pollination by hand. The best way I have found to do this is to take an electric toothbrush to each support truss and main branch. The more pollen to successfully fertilize the plant, the more seeds will be produced in the fruit (and therefore the meatier the tomato will be).
Just some final ideas for you on how to grow tomatoes. Flowering plants have strong light requirements in order to grow properly developed fruit. A properly built greenhouse usually provides enough natural light to grow healthy tomatoes. Check out high pressure sodium lighting tips if you have any doubts.
Also, I strongly recommend using a little lime in the transplant soil to prevent blossom end rot.
For the same reason, a dose of Cal-Mag once your tomatoes have fruit
set would not be a bad idea...simply mix in the recommended dose with
your normal nutrient solution.
Finally, the vines that grow out from leaf axials (where branches meet the main stem) are called suckers, and should be pruned off regularly throughout flowering. They suck up food that would normally be used to grow nice tomatoes. In 60 to 80 days, you too will be enjoying some homemade spaghetti sauce!
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)...
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 teas....like 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
And when I say decrease operating costs, I mean decrease them to almost ZERO, especially if you are producing your own nutrients...
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--->
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.
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!