Knowing the right time to plant tomatoes depends on your soil temperature.
I’m getting lots of phone calls and emails from anxious gardeners and tomato growers wondering if it’s time to plant tomatoes yet? The answer is…it depends!
Where are you growing? What’s your average nighttime temperature? Have you thought about taking the temperature of your garden soil? Soil temperature is the key to deciding when to plant tomatoes. The soil must consistently be 55 degrees or higher for tomatoes to thrive. My general rule of thumb for tomato growers in Southern California is to wait until the end of the third week in March. Then, check your soil temperature (I use a meat thermometer!) If it’s still too cold, give it another week.
If you’ve purchased tomato seedlings but it’s still too cold at night for them to be planted outdoors, let them enjoy the sunshine during the day. Be sure to keep them somewhat protected from the elements and give them a feeding of diluted liquid fertilizer once a week. Bring them in at night, putting them somewhere away from drafts or the furnace.