I am zone 6 SW PA and put mine out on Wednesday.

I put 50 plants in yesterday. Got to 49 degrees here last night. I don't think it will harm the plants to get them in and I really needed to because they were just getting too big and hard to keep watered on the patio!

With the cooler weather ahead, I'm waiting another week or 2, closer to Memorial Day. Why stress the plants in the cold soil?

I'm holding out until night time temps are at or above 50 degrees consistently. We've been ranging from 45 to 48 at my place. We're getting close to time and I've been tempted.

Part of waiting is I've had hail 3 times already, once last evening and twice week before last. NOAA is predicting some severe thunderstorms with large hail today and tonight. It's still easier for me to cover the flats or take them in rather than trying to cover in ground plants. But the plants are hardened off and the itch to get them in is strong!

I'm aiming for the big plant out next weekend but will check the 10 day forecast at that time. Got a few things in this morning. Been hardening off the trays since Monday.

It's very warm here, yesterday and today: 80's. However, the thermometer said 38°f, Friday. How Colorado gardeners at your elevations get to a consistent 50+ during the Spring ... well, I'm amazed.

Last week was not too bad for hardening off, as long as I could get things under protection in short order. My tomatoes have been something of a jumble, however. One of DW's favorites didn't come out from under plastic until today whereas I had about half of our tomatoes outdoors in the Sweet Spot a week ago.

There were an additional few plants that came out to the shade this morning. The toughies are on their southside taking whatever UV rays the sun throws at them. I'm wondering how I can get some of those in the garden right away and not drag the tender ones out there accidentally ...

Meanwhile, we are still planting onions! Stormy, windy cold weather has messed up an orderly plant out. We may hit 90° on Tuesday, then watch the afternoon highs drop down in the 60's! That seems like Colorado conditions to me. At least, the threat of frost looks like it's passed.

Steve

My goal is Thursday, May 24. I have an annual routine of taking the week before Memorial Day weekend off of work to harden off everything and get the garden planted. I also use the week to fertilize the yards and get other desperately needed household projects done. I schedule one or two tasks per day and start early in the morning, generally by 7:30 or 8:00, and try to be done by early afternoon so I have the rest of the day to relax and gear up for the next. It also allows me time to get protection in place should severe weather be in the forecast. I am usually done by Memorial Day weekend so I can kick back and enjoy the week's work. I have found there is a good mix of weather that week, in general, and it is often cool and cloudy which is actually great for hardening off. The plants still get the UV without getting scorched by 90-degree heat and I can leave them out for the better part of the day. 6 days is almost always sufficient regardless of weather.

We had 5 thunderstorms over this past weekend, 2 of which Sunday night produced hail to some degree. Fortunately, it was small and soft and did little but knock old flower buds off the trees. My tiny kale and lettuce seedlings are unscathed, so that's good. Boy, did it pour, though. Sounded like a mac truck on the roof.

I do believe we're free of frost at this point even with the very cool weather we've had the past few days. Lows have been quite mild and are expected to remain so. I've lived here long enough to know that you can never let your guard down, though, which is why I never push the warm season stuff much before Memorial Day. That's way too stressful for me and there's always plenty of time for production. Plants aren't going to do much until the weather warms anyway so I don't see any reason to rush it along.

nbm, I love the idea of the routine you've described! I can't do it this year (work is really heavy right now), but I think I may try to work it into future years!

It's definitely hard to manage hardening off starts while working full-time... I've generally started with two half-days over a weekend, and then leave 'em out Monday and Tuesday all day (possibly partly shaded), and then leave them out nights after that... but when the weather isn't good over the weekend (like last weekend!), it messes up the whole schedule!

Oladon, I didn't take the week off the first year I started all of my own seedlings and it was one of the most stressful weeks of my gardening life that I can remember. I could only put them out for a little in the morning, then garage them all day, then get them out immediately when I got home so they could get some sun, then back in the garage. If there was any bad weather in there, it set me back days. I figure if I just take the week off, I can monitor everything closely and fully maximize the amount of time they can be outside. I leave them out pretty much all day beginning on day one since I have a covered north-facing front porch that is well protected from wind and rain. I even introduce them to sun the first day if I'm lucky enough to have it. I always seem to have clouds and rain the first day or two and this year is looking like status quo (starting on Saturday which is supposed to be rainy and in the 50s). Everything hardens off very quickly given the time I can devote to the process - 6 days is just about perfect.

I joke with coworkers that I take the entire week just to harden plants off, but in reality I use the week to kick butt on household projects that would otherwise take the entire summer to get done. If I just hone in on one week and make a good list and stick to it, I can easily get it all done in 5-6 days.

I'm in southwestern Idaho.

I like to transplant tomatoes as soon as the plants are mature enough, no matter how cold it is in the spring (I like to cover them with milk jugs or something if it's too cold—with ventilation, of course). Anyway, they may not always grow too much during the cold weather, but I have noticed that the mature plants I put out earlier tend to be more productive, and the more mature plants seem to grow faster in the cold after the transplant.

I like plants to be old enough to start flowering before I transplant them, if possible, but if the last frost has already come and gone, I tend to transplant them before they're that mature.

However, this year, I'm having to transplant them late, due to the need to do a bunch of stuff with the soil (and how we had our trees taken out). So, I made sure to give them extra nutrients. They're getting nice and big, and plenty are developing flowers, now. I hope to transplant them this week.

As for melons and watermelons, I like them to be fairly mature and the weather to be significantly warmer than with tomatoes before I transplant them. They seem to do better that way. If I have to protect them from the cold, it's way too early to transplant most of them. Directly after the last frost is also too early. Starting them early definitely seems better here than direct-seeding them. The direct-seeded ones don't grow as large (both the fruits and the plants).

I'm still forming my views on transplanting peppers.

For tomatillos, I think I prefer direct-seeding to transplanting. Otherwise, I'm still forming my views on transplanting them.

I generally don't like to harden my plants off at all, unless you count opening the large vent on the greenhouse when it gets warmer (which does let a lot of the outside environment in).

I like to transplant when the sun is down, or when it's cloudy. I like to give the plants potassium or wood ash at transplant time, since it reduces the odds of transplant shock considerably.

If the plant has a lot of leaves that grew in protected conditions, I like to remove some of the old ones (because those are going to have a harder time hardening off, and I'd rather the plant spent its time worrying about growing new ones that are already hardened than trying to adapt the old ones that may never fully come to terms with the environment). I also like to remove leaves that were damaged from drought stress. Ideally, those leaves should be removed before the transplant, though (not after), and the plant should still have enough leaves to grow by. It seems like a lot of people don't believe it, but leaves (of mature plants) that aren't hardened off, or that were drought-stressed or used to other light, seem to be able to stunt a plant. Removing those leaves seems to allow the plant to grow more quickly again, despite how some people think more leaves is always better for faster growth, due to more photosynthesis, more mobile nutrients or something. While I agree that more leaves can be better, I don't think it is if they're not adapted to the kind of light they're getting; I also don't think more leaves is better if the roots are damaged, especially if it's sunny. I'm just talking about seed-grown plants like tomatoes and older watermelon (not trees and bushes, which are usually already outdoors or something anyway).

Our last frost this year was probably in mid-April (May 10th is probably the average). So, I'm pretty late with the tomatoes.

I just started transplanting ours. I think I got about 14 plants out, so far. There are about 45 to go. They're a lot bigger at transplant time than last year, and we have black plastic down, this time, to keep the weeds out.

I've transplanted West India Burr Gherkins, Shark Fin Melon, the Armenian cucumbers (Metki Dark Green Serpent x 3 and Amenian Yard Long x 1), Wonderberries, sunchokes (a whole bunch of them), all our onions and bunching onions, Morelle De Balbis, Otricoli Orange Berry, Chichiquelite Huckleberry, Lemon cucumber, Kikinda Competition Strain edible gourd, Serpente Di Sicilia edible gourd, and Rattlesnake pole beans.

The Wonderberries are growing fast. They're probably the easiest and earliest nightshade family plant I've grown. It's really tempting to grow large amounts of them and make pies and stuff, but although they're really fun to pick, they are quite small, and it would take a while to pick enough to make a pie.

I just planted Kiwano seeds in three spots. They're seeds I saved last year. I need to plant some ground cherry seeds if I'm going to do that. I didn't start any in the greenhouse, this year (tomatillos, either). I do have some reseeded tomatillos, and maybe one reseeded ground cherry, though.

Okay, I've got 41 tomato plants transplanted altogether, as of May 31st (in the ground with black pladtic on it). So, there are about 25 more (I may put some of them in another place). I transplanted some volunteer F2 hybrid squash, too (from our compost in the flower bed). We'll see if they survive!