Growing tomatoes from seed is a truly satisfying experience. Keen to get these tomato seeds out and ready to produce! OK, so you’ve been down to the local nursery and bought the types of seeds you think you will enjoy. What’s the next step?
The most crucial factor is that all danger of frosts has disappeared before you transplant your seeds into the garden plot (or your pots) because the frost will kill them. Tomatoes are just like us, they have their temperature preferences which happen to lie in the ranges of about 15 degrees Celsius to about 30 degrees (60 – 85 degrees Fahrenheit). Temperatures will vary according to your latitude and altitude. So, I like to get a head start and have my seedlings ready to transplant as soon as the danger of frosts is over. So how do we do that?
The obvious answer is to grow them indoors. You have to choose a warm sunny spot to get the seeds to germinate (grow from the seed to a seedling with leaves). A window sill behind glass is ideal as long as it gets some warm sunshine. Your seeds should germinate within 6 to 12 days depending on the amount of warm sunshine. You need a good seed raising medium to grow your seeds in. Your nurseryman will help you with this but a dedicated seed raising mix of peatmoss, perlite and vermiculite is an excellent medium to get your seeds started.
What pots are you going to use? You might have some old pots lying around in the back yard so you might want to re-use them given that there is so much emphasis on re-cycling these days. That’s fine, as long as you clean them up first because they carry the threat of fungal disease from their previous use.
Now that you have your pots, your seeds and your seed raising mix, the next task is to actually plant the seeds. Wet your seed raising mix first, then plant your seeds about 1/8” (3mm) deep and about an inch apart (2.5cm). If you’re using conjoined pots which are designed to take a single plant in each small pot that’s all you need to plant, although I still plant 2 seeds per pot in case one doesn’t germinate. If you get 2 to germinate then when it comes time to transplant into a bigger pot or into the garden pull out the weaker one and dispose of hygienically.
As soon as germination has taken place and the stem begins to emerge, your seeds need to be moved into the sunlight as they will soon start to form cotyledons, the first leaves or seed leaves.
Sunlight is necessary now for photosynthesis to take place. This is the process of the plant using sunlight, nutrients and water to manufacture plant food.
When the plants are about 2” (5cms) tall and have grown their first true leaves it is time to transplant them into a bigger pot. Now, if you have planted your seeds directly into a large (6”) pot that will be large enough until the plants need to be transplanted into the garden or your final pot.
The plants need about 6 hours of sunlight now to grow strongly and produce food. You might need to move them around the house to get sufficient sunlight.
When all danger of frost has gone, before you plant them out into their final resting place, it is a good idea to “harden them off”. This simple means put them outside for a few days to get used to outside temperatures.
As the seedlings grow you can keep growing tomatoes in pots or move them to a garden bed. Depending on where you are and the time of year growing tomatoes indoors is an option too.