When is the best time to start tomato plants from seed, so they’ll be ready to set out Derby week?
The Gardener’s Answer
Hello, Larry: Starting tomato seed indoors is a great way to get a head start on enjoying your crop. The average frost-free date for our area is May 10. Ideally it is best to wait a couple of weeks after this date has passed to set out tomatoes. Of course, this is just an average so watch the weather and if the nighttime temperatures are consistently in the 50s it is safe to transplant the seedlings into the garden. You do not want to start your tomato seeds indoors any earlier than six to eight weeks before the frost-free date, so the third week in March would be the earliest opportunity to plant your seeds. Potting up your seeds the first week of April will ensure that you are able to transplant them outdoors two weeks after our frost-free date has passed. When the time arrives, to start the seeds choose a container that has sufficient drainage holes and fill with a peat/perlite/vermiculite potting soil. Pro-Mix makes a good seed starting mix. The seeds should be planted 1/4 inch deep and 1-1/2 inches apart. Water well and keep the soil consistently moist. It should never be sopping wet since this can rot the seeds but do not allow the soil to completely dry out either. The seeds should germinate within five to 10 days. Once the seeds have germinated, make sure to place them in a south-facing window or use fluorescent bulbs to provide adequate light. Ideally the indoor temperature should be no lower than 70 degrees F. As the seedlings grow and the roots develop, they will eventually need to be transplanted into larger containers. Choose the healthiest seedlings and dispose of those that are not going to make it. When the time comes to transplant them into the garden, it is best to gradually acclimate them to this environment. Place the containers in a dappled light situation for the first couple of days and move them slowly into the full sun where they should be planted. This will reduce transplant shock and improve chances of a healthy tomato plant.