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Monday, January 9, 2012

KNOL: When to Start Tomatoes Indoors and Plant Outdoors

This is my Google Knol transfered here to be stored.

The short answer is 6 to 8 weeks before you regularly have fifty degree nights in your area. There are some basic questions to consider that will help you time your plantings.

When to Start Tomatoes Indoors & Plant Outdoors

by Gary Pilarchik LCSW-C

Some Basic Tomato Information

Tomatoes should be started indoors 6 weeks before last frost. That is a true statement but you want to make sure you also have warm nights. Tomatoes won't really establish themselves and begin to significantly grow until the nights in your area are regularly in the fifties. They are a warm season crop. I also know from experience you can start tomatoes 8 weeks before they go into the ground. The problem is that they get quite a bit larger indoors during that extra 2 weeks from 6 to 8 weeks.
Tomatoes also come with a maturity date. On the back of the seed packet it will say 55 days to maturity for some determinate type plants or 75 days to maturity for many indeterminate type plants. The key to this number is understanding that this "starts" when the plant actually goes into the ground. If you grow tomatoes indoors for 6 weeks, you won't have tomatoes in 2 to 3 weeks once planted. You probably save about 1-2 weeks of time by starting plants indoors.
The number of days to maturity is also dependent on the night time temperatures. If you put a plant out and the nights aren't warm, well the tomato plant just sits there. The maturity number on the back of the tomato seed packet is basically the number of days to maturity under warm nights. Confusing a bit but basically you gain 1-2 weeks time toward picking tomatoes by starting seeds indoors. The maturity timer starts when the nights are in the fifties and the plants are in the ground.


Some Basic Questions to Ask Yourself

You have to decide how you are going to maintain you tomato seedlings indoors. Do you want to just get them started in small seed trays and go from there into the ground?  Do you want to grow them in 6 inch pots or 8 to 12 oz styro-foam cups and grow larger plants? When do you get fairly regular fifty degree nights in your area? A dip into the mid forties is okay but you have to make sure the warmth is there.
I start my seeds in 9 pocket cello trays and put 3 to 4 seeds in each pocket. I end up with about 25 to 30 plants in one 9 pocket tray. I transplant them when the are 2 to 4 inches high into 8 to 12 oz styro-foam cups. The tomatoes in the cups can grow up to 12 inches by the time I transplant them. This takes a lot of work. I also sell my plants. The final question is how many tomato plants do you want to grow? You probably don't need as many as I do.


When Do I Start Them Indoors and Put Them Outdoors?

1.    Do you want to start them in 9 pocket cello trays and transfer them directly to the garden?
       Yes:    Start them 6 weeks before you have warm nights.
2.    Do you want to start them in 9 pocket cello trays and transfer them to 6 inch pots or cups?
        Yes:    Start them 8 weeks before you have warm nights.
3.    Do you want to start them directly in 6 inch pots or cups and grow larger plants indoors?
        Yes:    Start them 8 weeks before you have warm nights.


Some Basic Tomato Seed Starting Information

This Knol answered a specific question. I have detailed information in my other Knols on seed starting. I recommend you grow the plants in a starter mix that has fertilizer. If you are planning to grow larger plants over 8 weeks, you should give them a drink of water soluble fertilizer. Tomatoes will suck the nutrients out of starter soil quickly. I highly recommend watering the plants from the bottom.You can find a lot of information in my Knols below on growing and starting tomatoes.

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  1. Interesting post, I am so glad that I have visited your site. Really useful information!

    1. Thanks Nicole. Please visit again. I plan to blog all the pieces of vegetable gardening this year and shoot some videos. Good luck with your season.

  2. This comment has been removed by the author.

  3. Good stuff here, Gary, well-organized and helpful!

    1. Thanks for stopping by. I try to keep it interesting and easy to navigate but there really is so much information. So... I do my best. I appreciate the comment.


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