Tomato mulch: under the black plastic ...
(Iowa City, IA )
I've been mulching with black plastic for many years now. The trick to watering is to run a soak hose/ weeping hose under the plastic and about 8-10 inches from the plant stem.
I put out a 12-inch round, 1-inch deep dish, ran the soak hose over it, and timed how long it took to fill with water. If my area doesn't get the usual 1 inch a week rainfall then we hook up the hose and set the timer to make up the difference.
The plastic keeps evaporation down, keeps the weed seed from sprouting, and makes a nice edge to mow over - no flying wood chips, no molding leaf matter to set off my allergies. Tomato Dirt comment
Here are some great options for flat soaker hoses
and drip irrigation systems
beneath black plastic mulch in your tomato garden.