Gardeners who grow great tomatoes know one of the secrets is using plastic to trap heat under their plants. Not only do tomatoes love acidic soil, they like heat, including warm roots and warm soil.
Using Plastic Under Tomatoes
Plastic stretched under tomato plants does more than just keep weeds from growing. The black (or sometimes red) material absorbs the sun's heat and naturally warms the soil and roots of the tomato plant. Sun- and heat-loving plants thrive on the higher temps. Using newspaper as a mulch under the plastic also helps retain both moisture and heat.
How to Position Plastic Under Tomatoes
Black plastic can be laid down before or after planting your tomato plants. If putting down black plastic before planting simply cover your mounds with 2 to 4 sheets of newspaper, cover with black plastic (4 mil thick) and stake with "staple shaped wire," sticks or rocks. Use a knife to slit the plastic to plant your tomato. If your plants are already in the ground, mulch with 2 to 4 sheets of newspaper and stretch the plastic down the row, tucking it up close to the plant and overlapping on both sides. Secure with wire shaped staples in the ground.