On 3/18/10 8:44 AM, Billy wrote:
In article ,
Dave_s wrote:

My local Los Angeles, Calif and San Fernando Valley nursery says is
OK now to plant Brandwine and other similar variety tomatoes.
Other internet sources indicate that night temperatures are not at least
55 F so is too early. They indicate planting tomatoes in too cool soil
sets back the tomato plants. They indicate better to plant late April or
early May.

For Los Angeles, Calif and San Fernando Valley Can someone indicate
when is OK to plant my 4 inch pot 75 day maturing tomatoes in ground?

Thanks, Dave_s

Here on the North Coast, if we were to wait for 55°F evenings, we
wouldn't plant until mid-July. If you are past your last frost and have
8 hr. of sunshine, go for it. It would probably help to put some clear
plastic sheeting down, to help warm the soil, along one side of a row of
tomatoes, or a semi-circle for a single plant. Completely surrounding
the plant with plastic sheeting risks burning the plant, if it touches
the plastic during mid-day, and it makes it difficult to water.

Yes, plant as soon as the danger of frost is past. Actually, your area
has been know to get frost as late as 1 April.

However, frost highly unlikely, especially after the weather we're
having right now. I'm just 6 miles west of the Valley along US101. In
the last 24 hours, the temperatures ranged from 64F to 79F.
Temperatures haven't dipped down to 55F since Monday morning.

The 55F temperature is really a criterion for tomato plants setting
fruit, not for the plants to establish themselves. If the nighttime
temperatures go below 55F, the tomato flowers will not create tomatoes
unless artificially tweaked with a specific plant hormone.

On the other hand, the flowers will also fail to create tomatoes if the
daytime temperatures exceed 100F, which they surely will do in your area
this summer. There is no hormone treatment that will negate the problem
of high temperatures. Fortunately, small green tomatoes will continue
to grow, mature, and ripen with excessive heat even if no new tomatoes
are formed.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening diary at http://www.rossde.com/garden/diary