Question
We have an area under oak trees that we want to plant a lawn of some kind. We live in No. Calif. and only have irrigating water from Apr. 15 thru Oct. 15,so therefore the normal fall time to plant for us would be no water. WE have large acerage-the amount around our immediate home that we keep green and watered is nothing but pasture greens-don't know what else to call it-we did not plant it. What do you suggest?
Thanks
Joan

Answer
Good afternoon Joan:

Lawns under the shade of trees are typically thin, weak, and of poor quality. Maintaining a quality stand of grass under the shade of trees can be difficult and requires modifications in lawn care practices. Shade-tolerant grasses still need an acceptable amount of light to grow. In addition, lawns in shade areas generally do not have the ability to tolerate or recover from stress problems as compared to lawns growing in full sun.
Choosing a shade-tolerant grass mixture is critical. Perennial ryegrass and tall fescue offer intermediate shade tolerance. Perennial ryegrass cultivars for shade include Birdie II, Citation II, Fiesta II, Manhatten II, Palmer, and Regal. Tall fescues best for shade include Falcon, Finelawn, Houndog, Jaguar, Olympic, Rebel, and Rebel II. Start improving shade areas for grass growth by pruning the tree as much as possible to allow the maximum amount of light to reach the soil surface.
Care of lawns in shade areas should be different than lawns located in full sun. Mow higher (near 3 inches), and fertilize less in the shade, as too much nitrogen can be detrimental to shade lawn species. About 1 to 2 pounds of actual nitrogen per 1,000 square feet per growing season is all that is needed. When watering shade lawns, do so as infrequently as possible, and water deeply. Reduce traffic over lawns in the shade.
If these practices have been followed but the lawn still fails, there probably is not enough light even for a shade-tolerant grass species. Often a shade lawn mix is seeded, comes up fine, but declines rapidly due to a lack of sufficient light. If lawn grasses have failed, try a shade-tolerant groundcover or mulch, possibly in combination with ferns or woodland flowers. See the list I have provided below.
  Groundcovers as Lawn Alternatives in Shade         
Goutweed: Persistent, weedy groundcover that spreads via rhizomes. Tolerates many soil types, deep shade to full-sun; foliage may scorch in full-sun. Plant in contained areas to avoid becoming evasive.
Bugleweed: Low-growing, attractive foliage, spreads via above ground stolons. Prefers moist, well-drained soils in heavy shade to full-sun; protect from winter winds.    
Canada Wild Ginger: Forms foliage mass up to six inches tall, spreads rapidly via rhizomes. Excellent for partial to deep shade.   
Lily-of-the-Valley: Forms thick carpet of upright leaves, spreads rapidly via rhizomes, very adaptable but does best in well-drained soils, partial to full shade. May crowd out delicate plants. Large    quantities of roots and rhizomes are poisonous. Fragrant flowers are popular.    
Purpleleaf Wintercreeper: Trailing habit. Heavy shade to full-sun, prefers well-drained soils. Protect from winter winds. Scale can be a problem.    
Sweet Woodruff: Delicate deciduous groundcover which forms uniform mat of bright green, persistent foliage. Small, white flowers. Prefers moist, well-drained soils in medium to deep shade.
Hosta: Large group of hardy, dependable plants with bold, decorative foliage forming neat, circular clumps. Plants spread slowly via short rhizomes. Adaptable, best in open shade, leaf burn problems in sun. Slugs are a common problem.   
Japanese Spurge: Neat, uniform, evergreen groundcover, which spreads via rhizomes to form dense mat. Best in shade, well-drained soils. Protect from winter winds; may have pest or disease problems if stressed.   
Periwinkle: Trailing, vinelike evergreen groundcover, which roots as it creeps along. Grows in fairly heavy shade to full-sun; although foliage tends to be deeper green and glossier in the shade. Protect from winter wind and sun. Disease problems may occur with poor drainage and poor air movement.    
Barren Strawberry: Forms mats of strawberry-like evergreen foliage with glossy, bright green leaves and yellow flowers. Easy to care for, plant in partial shade to full-sun.    
Woodland Natives:  (various). A wide variety of woodland plants such as ferns, Jack-in-the-Pulpit and trilliums may also be used in areas where turf will not grow. Consult native plant specialists & nurseries.
  
If your lawn stays green most of the year, even though you have "Pasture Grasses" , that may be all you could hope for if you cannot water when needed. Keep in mind that grasses require a dormant period. Cool season grasses are trying to go into dormancy during the hot part of the year and if you water it to deter its dormancy you must keep watering deeply to keep it from being stressed.

I hope this helps you decide what to do. Either Tall Fescue or some sort of ground cover would be your best bet.
Good Luck
Floyd McMahon