Gardening West of the Causeway. With Don Shor & Lois Richter. Davis climate and region. River floodplain ‘Mediterranean’ climate: rainy winter, dry summer. Mix of soil types, mostly mineral Annual grasses and oaks 17- 20” of annual rainfall 90 degree highs June - September
With Don Shor & Lois Richter
Average high July - August: 90 degrees
Many pleasant spells in the 80’s.
10 - 20 days over 100.
40+ degree temperature swings
Hottest ever: 117F.
Hottest spells usually early - mid July
Very low humidity from May - October
Delta breeze is our natural air conditioner!
Sunset Zone 14, USDA Zone 9.
First frost Thanksgiving, last frost Valentine’s
Some nights in mid-20’s
Lowest ever: 16F (1990 freeze)
Latest frost ever: early April
Significant freezes in 1990, 1998
Coldest spells usually mid - late December
Tule fogs November - January
Valley fog in December - early January
Typical storms form in Gulf of Alaska, move in through the delta south of us.
‘Pineapple express’ storms come across the warmer Pacific. Warmer, wetter.
Typical first rain around Hallowe’en
1/2” - 1” typical per cold front
Heaviest rainfall Dec. - February
Significant rainfall rare after mid-May
Flooding can occur after soil is saturated.
Clay to sandy loams are typical.
Sandier loams close to creeks.
Denser clay loams on north, west.
No true ‘hardpan’, but a ‘plowpan’ in some areas.
Very low natural organic content.
Water penetrates slowly, runs off readily.
Soil naturally retains moisture: water slowly, deeply, infrequently.
Groundwater: water comes from wells.
High in dissolved salts: calcium, boron, and others.
High pH: water is alkaline.
Acid-loving plants have special needs.
Other plants may show nutrient deficiencies: iron, zinc.
summer and winter vegetables, herbs
‘stone’ fruit trees: apricots, cherries, peaches and nectarines, plums
persimmons, pomegranates, figs
seasonal (annual) flowers
‘Acid-loving’ plants require pH correction.
some plants are easy to overwater in heavy soil areas.
many apple varieties perform better with cooler autumns (and codling moth is a nuisance).
some subtropicals are marginal; truly tropical plants must be inside Nov. - March.
some high elevation or coastal plants can’t tolerate the long, hot, dry summer.