The height of the tunnel is determined by the height of the crop to be grown. Floating rowcovers made of lightweight spunbonded or woven fabrics can be placed loosely over the plants without wire supports. The edges can be held down with soil or stones. These are easier to apply, and are the choice for small gardens. Fabric materials can be used again unless they have been damaged or ripped.
Proper ventilation is essential, particularly with the hottest materials.
Allowing excessive heat buildup is the most costly and most common error with first-time rowcover users. As a general rule, if outside air temperatures approach 80 degrees F., additional ventilation should be considered. In years with unseasonably warm temperatures, covers do more harm than good. Normally, rowcovers are removed from vegetable crops 3-4 weeks after transplanting, and from Junebearing strawberries at the beginning of bloom to allow bees to pollinate. You may want to allow plants to acclimate gradually by increasing the size of slits over a 3-7 day period prior to complete removal.