Why Your Tomato Plants Stopped Growing

Variety

• Determinate tomato plants are genetically programmed to stop growing when they reach a certain height based on the variety. The plant then focuses on blossoming. The fruit sets and ripens around the same time. Roma tomatoes are one of the better known determinate tomatoes but there are other varieties. Indeterminate tomato plants keep growing until the frost kills the vine. The plant produces tomatoes all summer long, rather than within a short time period.

Temperatures

• Tomatoes prefer temperatures above 70 degrees Fahrenheit and no colder than 60 degrees at night. They are warm-season vegetables. If the temperatures stay too cool, the plant doesn't grow as fast. Expect growth to slow down and seem to stop as fall approaches. High temperatures -- above 90 degrees during the day slows down the growth as well. Wait until temperatures cool down, then cut the tomato plant back to within 12 inches of the ground. Feed and water well and it should start growing again.

Nutrients and Water

• Poor soil doesn't provide the nitrogen, phosphorous, potassium and other micronutrients tomatoes need. If growth has stopped, water the soil to a depth of 6 inches and then feed the plants with a water-soluble fertilizer. Water again so the fertilizer reaches the roots. Continue a consistent watering -- 1 1/2 inches a week and fertilizing schedule every two weeks -- and your tomatoes will start growing again.

Frost and Fall

• As the days get shorter and the temperatures cooler during late summer and fall, growth slows down. Frost not only stops the growth but kills the tomato plants. Before the forecasted first day of frost, pick the remaining tomatoes off the plant, they will ripen inside or use them in a recipe that calls for green tomatoes.

Disease and Insects

• Disease and insect infestation causes the plant to stop growing. Curly top virus is an example of a disease that weakens the plant. Inspect the plant as well as both sides of the leaves for damage or the insects themselves.