Growing tomatoes indoors assumes that you will be growing your tomatoes during the winter months as you wouldn’t be growing inside when you can get plenty of sunshine and warmth outdoors during the summer! So, the important ingredients when you are growing inside are light and temperature and we have to simulate the outdoor growing conditions inside to grow our tomatoes successfully indoors.
How Do We Go About It And What Do We Need?
Firstly you need to choose a spot where you can simulate the light and temperature conditions outside. Perhaps a basement where the temperature can be controlled by heating. Light can be provided by a single or number of grow lights. Temperatures need to be around the 70’s and no lower than the high 60’s at night, otherwise it will not be warm enough to mature the fruit. (In ̊̊C that is about 18̊ to 25̊ ). Grow lights can be purchased from your local hardware shop or specialist nursery.
Next, decide whether you are growing from seed or seedlings. Then decide the varieties you are going to grow. Are you going to grow indeterminates (the tall bushes which require staking) or determinants (the bush varieties such as the cherry tomatoes and the Romas)? For ease and convenience I always opt for the determinants as they are easier to manage and taste just as nice.
If you are growing from seed your local nursery will have plenty of varieties to choose from with recommendations for your growing location. As you are growing in pots it is a good idea to locate them where you don’t have to bend over. Maybe use an old table, a frame or even some old wooden boxes are just as good. Anything to prevent you from having to bend over! If you’re young it doesn’t matter but at my age it’s a primary consideration! I have made up a timber frame to stand all my pots on so that I don’t have to bend over for anything!
If you’re starting with growing tomatoes from seed you need a small pot to germinate your seeds in. Peat pots are useful as you can transplant you seedlings without disturbing the roots but any commercial potting mix is satisfactory and will do the job. If you are using punnets with individual compartments put 2 or 3 seeds in each one and as they germinate and grow pinch out the weakest and dispose of so that you only have the strongest seedlings remain.
Your light needs to be close to generate the heat for germination. As your seeds germinate and the seedlings start to grow taller simply move the growing light higher to accommodate the growth in the seedlings.
When the seedlings are about 3” to 4” tall (8 – 10 cms) and the true leaves have developed they are ready to be planted out. Plant out into large pots. Five gallon or 20 litre pots are a minimum. Larger is better providing more room for the roots to grow and if you are staking you need a fairly deep pot to support the stake. If you are going to stake now is the time to do it. After transplanting, water your plants in well.
The next consideration is watering and fertilizing. I use a mixture of seaweed solution and fish emulsion for fertilizing and later, in addition, I add in some chook manure (the commercial pellets) all of which are organic and produce excellent tomatoes. I fertilize about once a week with the liquid fertilizer and about every 2 to 3 weeks with the chook manure. This has a concentration of phosphorus which is beneficial when the plants start to flower.
Water as often as needs be. Keep the soil moist but not overly wet. Too much water can cause as many problems as too little. As you are growing indoors you will not have as much evaporation as growing them outdoors. A visual check will be sufficient to indicate the state of play.
Pollinating is the next consideration. As you are growing indoors you probably don’t want a hive of bees flying around your house! So how to pollinate when there are no bees? It is an easy process but a manual one. You have to do it by hand. Place your hand gently around the stem of the plant and shake it gently several times. This should be sufficient to do the job and if you do it once a week you should be producing plenty of flowers to bear fruit.
All you need to do now is to keep doing what you’ve been doing until the harvest. How do you know when they are ripe? Obviously color is the primary decider. When the tomatoes are red all over you can assume they are ready to pick. A further test is to lightly squeeze the fruit and if there is a bit of “give” in the skin rather than being rock hard, that tells you it is ready.
Finally, if there are any doubts, pick one, sprinkle a bit of salt on it and eat it. If it tastes delicious it’s ready!