I help young tomatos through the rainy and cold days of spring with my LED purple growlight. It does ALL the difference.

Tomatoes without light assistance get stunned and stay 1/4 the size of those under the light.

Purple lights supply plants with red and blue lightwaves which are the ones plants are optimized to absorve.

The advantages of LED growlights are low energy consumption, low temperature operation and ease of use.

Disadvantages are mainly high cost, nonexistent repair capability and lower area coverage.

This is all in a nutshell.