By Sarah Ransom
sransom@utk.edu

Gardeners can maintain their gardening environment to enable crops to grow for extended periods of time. With careful planning, crops can be extended a few days or weeks.

There are two main ways of doing this: management practices and structures or materials to alter temperatures. This week, we are going to focus on structures and materials.

Several methods for seasonal gardening may focus on absorbing or trapping the radiation from the sun to warm up the environment for your crops.

Dark mulches absorb light and conduct heat that warms the soil below; clear plastic covers transmit and trap light which increases the air temperature.

Agricultural plastics have made a lot of progress to improve seasonal planting. The biggest question is how much money to invest in materials and how much time goes into each structure and material used.

Passive systems, rely only on natural air movement and natural sunlight. These are the most flexible, most cost efficient and applicable for home gardeners.

Mulch can be used to influence soil temperature by absorbing the light and heat and then reflecting the light. Solid black and woven plastics also help warm the crops environment.

Mulch and plastics can also help reduce heat loss that comes from evaporated water or changing nightly temperatures.

Another structure that can be used is a floating row cover, also known as direct covers. These are plastic films, agricultural fabrics or buckets that can be laid or placed over a crop to hold heat. This type of structure is often secured by the soil, wooden posts or other materials.

These covers often need less irrigation, it depends on the type used, and how long they are placed, one benefit is they can reduce the speed of rainfall, which decreases erosion and crusting and can help protect against insects. Row covers are typically only used for temporary measures in the spring and fall.
Low tunnels are very similar to row covers and can be used to help extend the growing season. Low
tunnels give the appearance of a miniature greenhouse.
These need to be made sure they are appropriately vented to allow enough airflow, so crops do not get overheated.

Shade structures can help reduce the amount of heat in the crops environment, and this can allow for cool-season crops, such as leafy greens, to be grown longer in the spring.

If you are looking for a permanent fix on structures, you can build cold frames, high tunnels, and greenhouses.

All of these structures provide more control over your crop’s environment and can significantly alter the ability to extend your harvest season.

Regardless of how you choose to garden, there are many options for extending your fresh vegetable intake!

To check out additional information on seasonal gardening, read
www.extension.tennessee.edu/publications/Documents/W346-F.pdf.