Exclusion
For small areas, such as seed beds, install a 24-inch (61-cm) roll of sheet metal or hardware-cloth fence. Place the fence at the ground surface, and bury it to a depth of at least 12 inches (30 cm), bent out at a 90-degree angle.
Cultural Methods
In theory, packing the soil with a roller may reduce a habitat's suitability to moles. In practice, letting your lawn and/or garden go brown over the summer will almost always create conditions very unfavorable to moles, although this method is usually frowned upon by neighbors. Another even less aesthetically pleasing option is deep tillage, which destroys most existing burrow systems, but only up to the access points in adjacent lots.
Bio-Control Methods
Milky-spore disease is a satisfactory natural control for certain white grubs, one of the mole's major food sources. It may take several years, however, for the milky-spore disease to become established. Treatments are most effective when they are made on a community-wide basis. The spore dust can be applied at a rate of 2 pounds per acre (2.3 kg/ha) and in spots 5 to 10 feet (1.5 to 3 m) apart (1 level teaspoon [4 g] per spot). If you wish to try discouraging moles by beginning a control program for white grubs, contact your local Extension agent for recommended products, rates, and procedures. HOWEVER, the primary food for moles is earthworms; grub control may not have obvious impacts on mole activity.
Frightening
A great number of electronic, magnetic, and vibrational devices have been promoted as being effective in frightening or repelling moles. None, however, have undergone scientific efficacy testing. None have proven effective; they cannot be recommended.
Mole plant (Euphorbia lathyris), also known as gopher purge, caper spurge, moleplant, and a great number of other colloquial names, has been promoted as a mole repellent. The effectiveness of this plant in repelling moles is very much in doubt. Also, it is widely regarded as an extremely invasive weed. All parts of the plant are poisonous, particularly the seeds. It cannot be recommended.
Resources: (online)
Moles
