Q. Tell me when the first frost occurs in Las Vegas? I have tomato seeds that require planting indoors 5 to 6 weeks before the first frost.
|Freeze damage to plants can be as early as March 15 in the Las Vegas Valley|
A. If I give you that date, you will start tomato seeds too late. I start tomatoes from seed right around January 1 in the Las Vegas climate. The “first frost date” in the Las Vegas Valley is considered to be March 15.
|Tomato seedlings grown in the greenhouse|
March 15 is when, historically, there is a 10% chance frost will occur after that date. But in most years using this date is too late for calculating when to start seedlings. In some years you might put out tomato seedlings, with some protection, the middle of February. Other years it might be the first week in March. Rarely will it be the middle of March.
|Picture of a tomato transplant I got online but lost the source. Nice-looking transplant.|
By starting tomatoes from seed on January 1 you will be ready to put tomato seedlings into protected areas outside by mid February. If you discover this date is too early, delay putting them out for one or 2 weeks or until the weather gets better.
Watch weather reports for the coming week. This gives clues whether you can put tender seedlings out early in the season or if you must wait until later.
Seedlings need to be “hardened off” 2 weeks before putting them in the garden, particularly when starting them inside or in a greenhouse. Hardening off seedlings means moving them outside into protected locations and gradually getting them adjusted to a much harsher environment. Plunge them into this harsh environment gradually.
Protect tomato new seedlings if temperatures drop into the 40s. Freezing doesn’t occur until 32°F but tender plants like tomatoes can suffer “cold damage” at temperatures in the 40s. Think about what happens when you put a banana in the refrigerator. Tomato plants are also tropical, just like bananas.