Tomatoes do not set fruit well when the nighttime temperature is below about 60 degrees or above about 70 degrees or when the daytime temperature is consistently above about 92 degrees.
Now take a few seconds and reread that again.
Now ask yourself, “how in the heck do we ever get any tomatoes here in Oklahoma?”
The answer is to plant early.
I remember back in the mid-eighties when I was managing a vegetable operation in western Oklahoma. We decided to stagger our planting dates for our cantaloupe, planting the first, second, and third week of April.
When do you think we harvested? Yes, they all became ripe at the same time.
For most of our warm season vegetables, it is of no benefit to tempt fate and Mother Nature by attempting to get these out into the garden early.
Tomatoes are the exception to the rule.
Tomatoes need to be planted into the garden even when there is a good chance of a light freeze or hard frost. Tomato plants need to be of a certain maturity level for them to start blooming.
Now is a good time to start your tomatoes indoors. There are several tabletop seed starting kits on the market. The Jiffy-7 is probably the most common. If you have a heating pad, and your spouse will let you use it, you might not need to purchase the heating pad used by the Jiffy-7.
Purchase a good potting soil. Put it into a clean bucket and add water. Many of the potting soils are hydrophobic. If they are not pre-wetted, they will shed off water when you attempt to water the containers. Initial container size is debatable. I prefer to start with small sizes and then transplant up to larger sizes.
Light is not required for germination (lettuce is an exception), but will be needed after germination.
A plant grow light is not required. I have found that a four-foot shop light with cool white florescent bulbs will suffice. The shop light will need to be raised as the plants grow. Keep the lamp one to two inches above the growing plants.
Water the containers when the potting soil lightens in color. Water bottles with the sports lid that you pull to open make excellent “waterers,” since they allow you to accurately direct the flow of water to the base of the plant.
Now back to the planting early subject. I like to plant my tomatoes in late March, knowing that we will have a “Tax Day” freeze.
The secret to protecting the tomatoes is your garden hose. Dark wet soil will absorb more solar energy than a light colored, dry soil. Most of us gardeners usually have a stack of one or two gallon black plastic pots lying around. Wet some newspaper and push the wet paper into the drain holes in the bottom of the pot. Just turn the pot over and sink it several inches into the mud. I have successfully saved tomato plants from temperatures of 25 to 26 degrees.
Another reason to start the tomato plants early is that I like to plant tall plants. I will take a 12-inch-tall tomato plant and trim away all of the leaves and branches, leaving only three to four leaves at the top of the plant. I will plant the plant deep with only the top three to four inches of the tomato plant above the ground.
This accomplishes two things: 1) The tomato plant will put out a root system all along the stem to nourish the plant, and 2) The short plant will be easy to cover for freeze protection.
Ray Ridlen is an agriculture/horticulture educator for the Oklahoma County Extension Service. His column addresses frequently asked horticulture questions. For more information, call 713-1125.