Enjoy, not all zone 5's are created equal. Zone 5 just tells you the lowest temperature it gets in the winter. I live in zone 5 in Burlington Vermont, traditional danger of last frost around here is Memorial day weekend. My understanding is really by the lake the date for last frost is earlier because the lake keeps things a little warmer once if defrosts. However this year the night time temps this coming week are still supposed to be in the 40's. I may wait, not frozen but still cooler then the 50 degree temps I have read they should have at night.

Your local garden center should know the answer for your zone 5.

-Robin

I usually plant my tomatoes the second week in May...after the threat of frost is minimal. HOWEVER this year I have most of my tomatoes sitting in small pots on the patio because of the crazy cool and wet spring we have had.
I have good luck with tomatoes...probably because my neighbor puts horse manure on my garden all winter long and tills it in for me in the spring. i fertilize my tomatoes with standard tomato fertilizer when I plant them and each month afterwards. I also water them with a soaker hose when it doesn't rain...to be sure they get at least an inch of water a week...

In in Zone 5 in NY. Like Robin Kate, I usually don't plant out until Memorial Day weekend. So far I have 18 planted and 5 in containers. I have another 25 or so to plant in the ground.

I'm in zone 5 in upstate NY and having learned the hard way about late frosts, so I never put out plants until about two weeks after the last average frost date, which for me is about mid-May.

So plants won't go out until about the beginning of June if the weather is settled then.

Carolyn

We normally plant them out Victoria Day weekend May 17-19 but this year has been so cold and wet I just got them out yesterday. A few night this week the temps are to be low and I'll still need to cover them up.
The last 5 years we had very hot and early springs so we put them out sooner and just covered them up if frost was likely.

Our temps here have been up and down but I've had my tomatoes outside for about three weeks. As soon as the low temps cleared 45 degrees at night, I stopped covering them with plastic at night. They started producing flowers last week. This weekend I noticed little tomatoes. The three biggest plants were put in upside-down buckets on Saturday.

I also have seedlings outside that are too small to go into my upside-down arrangement but they are in 3" pots. I haven't decided yet if they will go in bigger pots before I put them in their buckets.

I've always heard that May 15th is the cutoff day for last frost...I plant out earlier using WOWs...I also have a deep raised bed so the soil warms early and I rarely have to irrigate...

dido... memorial day weekend.

enjoy :
your question begs a subjective answer. Where in zone 5 is the first variable, and the types of annuals is the second.
Here in the center of the country, the weather at a particular time will be far different then , say, the east coast.
Our last average frost date shows April 15th.

You have to be well aware of the weather patterns in your neck of the woods.

It MAY not frost after April 15th, here but it well could until about the end of April.

Your annuals may coinside with the tomato planting calander only to that end. I would find out the best soil temperature for your flowers and or plant them out a couple of weeks after the last average frost date for your area.
Be aware that many weather factors affect success, but planting at the correct time may only be a concern with freezing and soil conditions.
Remember we are only stewerds and the planet has been doing this for a long time, plants, especially native to your area, are extremely able by design to survive the ebb and flow of the different climate and micro-climate changes, such as the natural ones we are going thru presently.

Tom

I braved it and put out two of my older tomato plants and a few annuals in pots last weekend. We'll see. It has been in the 40s and so far the plants didn't die but I don't know if that will still hurt their tomato production. I took the chance.

kristie :
Consistant 40 degree lows won't hurt. They will just wait until the soil and air warm and then take off!:)
you would have to speak to a higher authority. Say a non practicing professor/author, or a gardener that has done research on tomato production, with a control plant at different planting conditions.
I have planted very early before and had decent production later in the summer.
Last year I planted mid to late April and had extremely heavy fruit set on before the 4th of July. Lost every one to critters, but the second blossom yielded about half to 3/4 that many during harvest. Good Luck!!!!!!!!!!!

Mine went out ten days ago and had one close call when it dropped to 34 degrees. But they are looking great and I just side-dressed them with 10-10-10 a couple of days ago.
Today was sunny, warm and humid - great tomato growing weather.

Thanks Tom. I wasn't sure if I was hurting the plants by putting them out now knowing the temps do get down in the 40s some nights. I've put them out this early before and had pretty decent production so I'm hopeful again. As long as the hail stays away.

After growing toms for over 35 years, I have FINALLY stopped worrying about getting them out @the last frost date !

If the ground is too cold and wet--they wont do squat anyhow.....Geno

I put mine out on April 22nd in WOWs and as of today I have fruit forming on all of my six varieties! The most advanced fruit is on the Purple Prince (pictured), which is a faster developing tom (75 days)...

Hi There Enjoy,

I live in Zone 5, Youngstown, Ohio. and I put about 1/2 my plants out around May 15th, and the other half went outside June 1st of this year...I had started them inside with HID lights and they were already a month old to 6 weeks when they went outside.

Best of luck,

Elliott

I'm in Sheboygan, WI about 1/4 mile from Lake Michigan. The lake is a blessing and a curse. Without it I'd be in Zone 4 like most of Wisconsin. But it makes for cool foggy springs until the water warms up and then pushes back the first frost in the fall until late October. The rule of thumb here is to not plant until Memorial Day, but this year we had frost warnings on Memorial Day, so go figure. Last year I got away with planting about mid-May, but I was lucky. Also the plants just sat there and didn't grow until things warmed up, so there wasn't any point to planting them sooner. This year I planted on May 31st and my plants started getting growing right away. I think that's going to be my planting date from now on.

Mike