Full sun for happy orchard fruit trees, with fruit production levels not being the only reason to put them where they will get plenty of light.

More sun = higher brix levels = sweeter fruit. I would always plant fruit trees in the sunniest position available to maximize both production and taste.

being in Zone 10a you may not get much fruit from that tree as it generally wants 500 chill hours (not knowing where you are, this may or may not be an issue). But more sun is better:

Photosynthisis = Sunlight turning water and CO2 into Glucose (sugar) and O2

The Sunset Western Garden book recommends Sekel for most parts of California. The exception would be the extreme southern coastal belts, as their winter climate is generally too mild.

Thanks all!

Rhizo - I am in Z10 but we get 600 chill hours, so I went off that information when picking seckel (which only needs around 500 right?). The park across the street from my house has a walkway lined with pear trees, although I don't know the variety. I also planted a comice this year, but it is my first time growing pears so it's all a learning curve for me. I live in Oakland.

It seems the consensus is as much sun as possible, which makes sense! I'll plant the seckle this weekend in the sunniest spot.

Thanks!

Grace, excellent! Your zone raised some questions about the suitability of the Seckel, which is generally limited to zone 8 locations at the warmest. But that's on paper only!

And rhizo's comment above motivates me to clarify that the hardiness zones have minimal relationship to anything other than the average winter low. So reporting plants with a range of hardiness zones in misleading at best. :-) If a plant is expected to survive a zone 5 (as the lowest zone quoted) then of course it will survive a zone 8...or 9...or even a 10! There are other factors that can come into play, including chill hours or lack of sufficient dormancy for some plants but that is only tangentially related to USDA hardiness zones.

I am in a pretty firm zone 9 yet I have around 1600 chill hours to play with :-)

In zone 10 hot climates, the trees may prefer just a little shade better than full sun.

This is especially true for helping tip necessary winter chill accumulation requirement.

It is different in different climate. Always want full sun is conventional wisdom from colder north climate, where most American live in past.