Here's the Texas guide. http://aggie-horticulture.tamu.edu/archives/parsons/earthkind/ekgarden14.html

You can now see why this is difficult. Do you see all the various planting zones for Texas alone? Then each different variety of plant has a different maturity date. Eg. some cabbages mature in 60 days, some in 110 days.

Unfortunately I did not find a harvesting guide for Texas. we have one for Georgia and it lets gardeners know when most crops will be harvested. You take the harvest date and simply count backwards using the days to maturity on your seed packet. I add to this the days for germination, and a week for a transplant to settle in once planted.

Here is a link that might be useful: Texas planting guide

Here in AZ we have great guides that list best times to start seeds indoors and best times to plant seeds outdoors and best times to set out transplants that show harvest seasons and extended harvest seasons for all kinds of crops. Is this not the norm for the rest of the country?

Below is one of the four planting calendars I use. Others have similar information. There must be something similar to this for where you live.

Here is a link that might be useful: Low Desert Planting & Harvest Calendar

girlgroupgirl, I have multiple planting guides for when to put the plants out in the garden, I just thought it would be very doable for some industrious programmer to create a website that took the USDA zones, the crops and the average time before the planting date to determine when to start the seed. Yes, I can see why it is difficult but I also think this might be doable.... just not by me! :-)

thisisme, that's pretty much what I was looking for, thanks!

Johnny's Seeds has something maybe like what you are seeking. Take a look:

http://www.johnnyseeds.com/t-InteractiveTools.aspx

This is a very handy seed starting chart that can be customized by whatever "last frost date" you enter.

Here is a link that might be useful: You Grow Girl - Seed Starting Chart

I second johnnys. Theirs allows you to consider a number of variables.

The best source will be the database that you create yourself, starting this year. There is no way to have an exact method, because every year is different (and this year is REALLY different), so I tend to stagger my planting dates a bit. This also gives the advantage of staggered harvest dates, which is better for fresh eating. If it is a crop that is intended for processing, I plan my planting around a later start date, to be sure of best growing conditions, and plant a large amount, so that I will have a large quantity to preserve all on the same day. Knowing what variables to consider is always important, but no amount of planning can compensate for the unpredictability of dealing with natural phenomena.

That being said, I too find Johnnys' a great resource for this and many other guides. Their Interactive Tools section is truly a gift for garden planning.

Almost none of the South-East US as far north as parts of NC/TN/VA didn't get an extended hard freeze.

Disease and pest pressure in the Mid-West and North-East is going to be a lot heavier than normal and earlier than usual...not to mention how early it's going to be in the South/South-East.

It's going to make for an interesting year and a great reason to keep a journal in case (aka, when) this rare occurrence happens again.

...get a local planting map for your area, experiment with planting earlier than the suggested time when you're comfortable, find out what stuff grows from seed and what should be started from seedlings, what pests/disease are getting at your plants, and record your findings along with whatever temperature/environmental stats you want to keep.

"Almost none of the South-East US as far north as parts of NC/TN/VA didn't get an extended hard freeze."

That's supposed to be...Almost none of the South-East US as far north as parts of NC/TN/VA got an extended hard freeze. AKA, a lot of states that usually get hard freezes didn't even get enough cold to wipe out soil borne disease or over-wintering insect populations in normal amounts.

Bad sentence structure and lack of attention strikes again. I should proof-read more often.