At first blush, tomatoes may seem easy enough to grow.

Some gardeners start their own tomato seeds because selecting from the options in garden catalogs is too good to pass up.

Others prefer to purchase seedlings ready to transplant into a container or garden bed.

Generally, once the plant is in the ground, the countdown to harvest begins.

While tomatoes are relatively easy to grow, there may be a few challenges along the way and that makes the end prize more compelling.

Regardless of the type of tomato, there is a series of stages tomatoes go through before arriving at that perfectly ripe first bite.

Those stages are an important key to understanding when asking, “Is this tomato ready to harvest?”

When thinking about those stages, consider the roles of lycopene and ethylene, respectively, in the maturation process of a tomato.

Lycopene is a carotenoid that provides the red coloration to many fruits and vegetables.

Ethylene is a gas naturally produced by maturing tomatoes.

In some cases, tomatoes are harvested green, loaded into a chamber where they are flooded with ethylene.

The resulting tomato may not be as colorful nor as tasty as a tomato allowed to stay on the vine longer for the natural ripening process to happen. Here are the Six Ripening Stages of Tomatoes:

1. Green Mature Stage. At this point in the fruit’s development, color will be visible inside the fruit but not yet visible on the outer skin. If the fruit is picked at this point, the flavor will not be fully-developed.

2. Breaker Stage. In the Breaker Stage, color will be visible at the blossom-end of the tomato skin and tomatoes are considered to be “vine ripe.”

The color change at the blossom end indicates the tomato is producing ethylene, a ripening agent produced by the plant.

It is also at the Breaker Stage that the tomato receives no additional nutrients from the plant. In fact, a skin will form between the plant stem and the plant, effectively cutting off nutrients from the plant to the fruit.

3. Turning Stage. In this stage, between 10 and 30 percent of the tomato’s skin is pink, pinkish or red.

4. Pink Stage. In this stage, the coloration has spread to 30 percent but not exceeded 60 percent of the tomato skin. The fruit is also becoming a bit softer to the touch.

5. Light Red Stage. In the Light Red Stage, the coloration has spread to 60 percent but has not exceeded 90 percent of the tomato skin.

6. Red and Final Stage. At this point, 90 percent of the tomato has that classic red color and is ready to eat from the vine.

The question of whether or not a tomato is ready for harvest continues to be a debate among many gardeners.

From a strictly physiological perspective, tomatoes are ripe at the Breaker Stage; however, those tomatoes will not have the classic red (or yellow or orange) color.

In addition, conventional wisdom is that a tomato is vine-ripened when it’s reached its full color.

It is important to remember that tomatoes continue to ripen even after they are picked.

In fact, if the weather stays very hot, above 85 degrees, then ripening slows or stops.

To avoid storm damage and sunscald, it may benefit you to actually ripen the fruit off the plant.

“Growing Green” is contributed by Diane Dorn, Lehigh County Extension Office Staff, and Master Gardeners. Information: Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613