I was wondering the same thing. I was waiting until May 15th because we put so much effort into our little plants that we've grown from seed and I don't want to risk the worst case scenario of a frost.

We did put our carrot seeds directly into the ground this weekend (in Logan).

Todds_sweetpea, since this is your first time starting form seed.... you do know that you have to slowly acclimate them to sun and wind before planting them in the ground, right?
I just started to harden mine off yesterday. I am covering them up at night with a clear pool cover. Keepin' my eye on them to make sure that they don't get sunburned. I figured that by the time they're hardened off in the next couple of weeks, it will be time to put them in the ground. Will still have to watch the weather for frosts until mid May.

Oh my, we've given so much attention to our little plants that we started from seed and didn't realize that you need to harden the plants up before transplanting outside. Would putting them outside in the sun for a few hours each day be enough if I did that for 2 weeks?

I usually start mine off in a shady spot for a couple of hours. mine are in full sun now after about a week of going in and out. I am antsy to get my tomatoes in the ground, but I have to wait. I will watch the weather til mothers day. thats may 10 this year. I've got radishes, carrots, lettuce up and yesterday set out all the cabbage, broccoli, brussels. I plan to start another batch of carrots tomorrow. They take about 3 weeks to come up. My cukes are barely coming up in their cups, no squash, cants, watermelon yet. I started peas in cups this year. When they get a couple of inches taller I will transfer to garden tubs.

My main tomatoes went out in Wall-O-Waters on April 11. I hardened them off for 5 days before planting and they survived. I have 2 more trays of gallon tomatoes in the garden acclimating them to the heat. They also are surviving.

However, without protection I plan on Mothers Day in Salt Lake for everything frost sensitive, eggplant, ocra, cukes, squash, unprotected tomatoes, etc. I start looking at the 10 day forecast on May 1st and that determines what I do.

I meant to get my wall-o-waters up earlier, but I finally got them set up today, I'm hoping to get the first few tomatoes planted on saturday. I've been hardening them off for several days now.

The rest will wait until early may.

Ha, which is like next week. I think I'll just watch the weather and see when it looks safe.

Jimh6278 is right on. For me tomatoes go in (after hardening for about a week) last week of April under hotcaps. Under the hotcaps, like wall-o-waters they stay protected and grow better from the heat that is trapped. 2-3 weeks later depending on the forecast, I cut the tops open slightly so they don't get sunburned and then open up the tops gradually over the next few days until I take the hotcaps off completely. Wall-o-waters work fine for this too, I just prefer hotcaps. I live in Spanish Fork and our frost free date is about May 12th.

Here is a link that might be useful: My gardening blog

About Wall-O-Waters. It is important to somehow provide a support to keep them from collapsing. The advertising literature says it is not necessary but every once in a while they will collapse and crush weeks of hard work. I cut the legs off tomato cages, turn them upside down, and work the top ring a couple inches into the ground. It makes a pretty stable structure. And it allows you to put a garbage bag over the whole thing if the temp is predicted to be under 30. They are supposed to protect the plants at 25 but why take a chance. The garbage bags can always be returned to the box.

I have planted out without hardening and it basically takes about 3 days for them to acclimate and start growing. But, I start my seeds under a florescent that is kept about 3 or 4 inches away. That may be the reason they do ok. Many plants can safely go out. Just look up what you have to see if it is frost tolerant. And if a frost is expected you can use newspaper or other paper to cover them and that is all they will need. Starting from seed is definitely the best because you can get a taste of gardening much earlier. And that just feels nice on those cold March days.

I just planted mine today and did a blog post about it and the dates etc. If you are interested go to.

http://www.vegenag.com/2009/05/planting-tomatoes-in-utahor-anywhere-else/

Here is a link that might be useful: My Blog