Soil Temperature and Moisture Tables

Soil Temperature (F) Soil Conditions
Less than 20 Degrees

Deep Freeze - Winter Kill Imminent

Less than 33 Degrees

Frost Line - Soil Frozen

Less than 50 Degrees

Too Cold To Plant - Root Growth Only

51 - 59 Degrees

Minimum Growth / Optimal Root Growth

60 - 75 Degrees

Optimal Growth

76 - 90 Degrees

Ideal Growth

Soil Moisture Soil Conditions
The centibar (cb) is an agricultural unit of soil water tension (water pressure on plant roots)
0-10 cb

Saturated Soil (Free Water Range).

11-30 cb

Soil is adequately wet (Field Capacity Range).

31-60 cb

Irrigation Initiation range for most soils.

61-100 cb

Usual range for irrigation in heavy clayey soils (Limit of Readily Available Water).

101-200 cb

Soil is dangerously dry.