heat mats- how long do seedlings need heat?

[dice]

My seedlings are so fragile I wasn't sure if something was wrong or if they would get tougher.

Some people put a fan on them, so the stems will thicken up.
Others just brush them with their fingers a couple of times
a day if the plants are easily accessible for that.

See
http://en.wikipedia.org/wiki/Thigmomorphogenesis

Some big greenhouses have fans for ventilation, but the industy
has chemicals for producing that look in a seedling, too.

Plant them deep, so that just the growing tip and one set
of true leaves is showing. You probably have warm soil there,
so deep planting (deeper root system, so access to water
down deeper) is probably more useful than trench planting
(shallower root system). Then it does not matter if the stems
are spindly at transplant.

It seems like they should already be outside and growing
in the sun in your part of CA.

[kpatrick925]

Originally Posted by dice

Some people put a fan on them, so the stems will thicken up.
Others just brush them with their fingers a couple of times
a day if the plants are easily accessible for that.

See
http://en.wikipedia.org/wiki/Thigmomorphogenesis

Some big greenhouses have fans for ventilation, but the industy
has chemicals for producing that look in a seedling, too.

Plant them deep, so that just the growing tip and one set
of true leaves is showing. You probably have warm soil there,
so deep planting (deeper root system, so access to water
down deeper) is probably more useful than trench planting
(shallower root system). Then it does not matter if the stems
are spindly at trasplant.

It seems like they should already be outside and growing
in the sun in your part of CA.

They are outside now but just since Friday. We have had late rain and cold in my area so I hadn't put them out sooner. I don't have much protection from the winds, rain or sun so I was holding off till things got more stable. I am closer to the water so we still have cool nights although it looks like lows that are high 40s to low 50s now. Mid week it is supposed to be mid to high 70s to low 80s with lows in the 50s so I'm hopeful that things will even out and not have such wide swings. The cities all around me are warmer but because we are so close to the water (i've been told) the temps are usually about 10 degrees cooler. Good for me but sometimes not so good for growing. OK, I am going to try the rubbing stems but I think by the time I plant the soil will be warm. Also, I am doing a lot of container planting and I think that is typically warmer, right? Anyway, thanks for all the good info. I appreciate it and the links!!

[dice]

De nada. I was going to ask you whether your local
micro-climate was more Bay Area or Central Valley.
We have had a cool spring, too. Those cooler temps
will come in handy if mid-summer temps get up in
the high 90s F. You will get fruitset when people around
you in warmer locations are seeing only blossom drop.

[rick9748]

Why no grow lights.Buy the cheapest shop light Lows has and 2 grow lights.$40.00 and works great.I just put mine, the light, on top of 1 gal paint cans and let them go.

[slugworth]

walmart has the 6500K t8 bulbs for $7.88 and a fixture should be around $15