Question: What are the features I should look for in a grow tube?

Answer: 1) Circular shape. Triangular and square designs absorb more heat at certain times of day when the sun's rays are flush with a flat surface of triangular or square tubes. With a circular tube only a small portion of the tube is ever facing the sun's rays directly, reducing the absorption of heat.

2) 3.5 inch diameter. Research shows grow tubes that are 3.5 inches in diameter dramatically increase total vine biomass production. Tubes of 3.5 inches in diameter produce 70% more total vine biomass, with thicker stems, and balanced root/shoot ratios.

3) Opens from the side. Grow tubes are left in place until after the vine is trained to the cordon wire. A well-designed grow tube allows you to remove it for re-use without untying the vine.

4) Pink/beige color. This color optimizes the ratio of light frequencies plants need for photosynthesis. This color gives vines the same sensory feedback as being in full sunlight, so that they allocate growth resources to 'secondary' growth - stem thickness and roots.