Know When to Plant What: Find Your Average Last Spring Frost Date

How to find your average last frost date.

| April 11, 2008

sowing seeds

It’s important to plant your garden seeds at the right time, and the key is knowing when your area will see its last spring frost. Some garden plants taste even better after a little frost, but you'll sure be sorry if you put your warm season crops in the ground too soon.


Some crops thrive in cool weather, while others only grow well when it’s warmer. So how do you know when to plant what? The key factor that should guide your decisions is your average last spring frost date. Most cool season crops, like cabbage, broccoli, lettuce and many others, can tolerate a light frost and will grow best when sown a couple weeks before your last spring frost. Some, like peas and spinach, are so cold-hardy they can even be planted “as soon as the ground can be worked,” as many seed packets say. But warm season crops like squash, cucumber and basil will be killed by frost if your seeds come up too soon. Ditto for warm season transplants such as tomatoes, peppers and eggplants — if you don’t wait until danger of frost has passed before you set them out, a late frost will kill them.

Thus on seed packets you often see “Plant after all danger of frost has passed.” So, how do you find the average last spring frost date for your area? There are U.S. maps that show last frost dates, but it’s hard to find your exact local dates on them. Your best bet is the National Climatic Data Center. Choose your state and then locate the city nearest you, and it will show your average last spring (and first fall) frost dates, based upon weather data collected by the National Climatic Data Center from 1971 through 2000 from that location. You can choose between a 50/50 probability of frost after the given date, or you can play it safe and choose the 10 percent date, which means there’s only a 10 percent chance of a frost after that date. The Freeze/Frost Occurrence Data charts also provide average dates for 36 degrees Fahrenheit, 32 degrees and 28 degrees; for most crops gardeners should use the 32 degree dates.

Another great tool to find your average frost dates is the MOTHER EARTH NEWS Vegetable Garden Planner. The Planner will even send you customized planting reminders for which crops need planting based on your frost dates and location.

Here’s a summary of which crops to plant early, and which ones not to plant until after your last spring frost date:

Very early spring (as soon as the ground can be worked)

  • Onions
  • peas
  • spinach

Early spring

  • lettuce
  • beets
  • carrots
  • radishes
  • dill
  • cilantro
  • cabbage
  • broccoli
  • celery
  • kale
  • potatoes

After last frost date

  • beans
  • corn
  • melons
  • cucumbers
  • squash
  • tomatoes
  • peppers
  • pumpkins
  • eggplant
  • basil

For more information on planting dates, organized by region, see What to Plant Now.

4/18/2014 8:25:57 PM

Hi Gardners! Can anyone give me some good advice on successfully growing tomatoes in Conway, SC area?? I seem to fail each year. The plants do very well, look healthy, then when I get tomatoes on them...they start to turn yellow, then brown, or blossom end rot, or something every year. Thanks...

Jen Carres
3/18/2012 8:37:23 PM

Now is a great time to plant a TickleMe Plant. The leaves fold and the branches droop when Tickled .

2/22/2011 1:09:37 AM

Thanks for the chart and the great info! We live in a 3 stop light town and I was super surprised to see us! It's been several years but I've planted multiple gardens in the past. This year I'm actually planning and doing a more scientific approach and doing the long term thing(ie: raised beds, greenhouse, succession planting, companion planting, blah blah). I'm having fun and hopefully will make this one work long into the future...thanks again!

ann _1
4/23/2010 5:52:31 PM

Sarah, And the rest of you. There is a book and you can find it all over the internet. It is called the Vegetable Gardener's BIBLE (not the Bible as in God's Word) but this is the best book for gardening and companion gardening. I did 1/2 an acre garden just like his (Edward C. Smith). And it cuts down on weeds and I know now how to companion plant. I hope this helps.

3/28/2010 4:46:54 PM

A crafty gardener will willingly lose crops on both sides of the growing season as he plants early and late in the season gambling that he will beat the actual (but always unknown)time of killing frost.

3/27/2010 11:18:52 PM

Mary...(posting on 3/21/10)..if you use the link in the article (National Climatic Data Center) it will bring you to an easy to use chart. There are 3 columns for each zone with percentages and 3 rows with 28/32/36 degrees. Find your city (or the one closest to you) and then just use the chart. The columns are marked with percentages. I believe that the middle one says "50". So for example if the chart says May 10 under "50" and in the row labeled 32, that means that there is a 50 percent chance that it will be 32 degrees on May 10. Hope this helps some. It is a bit difficult to read because the column headings do not "travel" down the pages, so you have to remember what each column is marked. We are in Stockbridge, and we use the Lansing information which works out well. GOOD LUCK.

Mary McAvinchey
3/21/2010 9:56:36 AM

Ok, I don't know about anyone else, but I've been trying to find out the last frost date for my region and can't find it. It shouldn't be this difficult. Michigan, Midwest or Northeast area.

Bethany Lamb_1
2/11/2010 9:35:43 AM

First time reader - thanks for the great info! We are starting our first garden this year **Fingers Crossed**

8/5/2009 1:31:00 AM

Started reading Mother during the 80's. Been working on a complete collection ever since. A few have eluded me but its about 90% complete. Thanks for this article, for that matter thanks for all of them. fuzvulf *(Fuzzy Wolf)

Fred Baginski
4/29/2009 7:32:15 PM

I think I started my seeds a little too early and some of the plants were starting to turn yellow. I went ahead and put them out last weekend and am hoping that no frost comes. A couple of plants I ordered were delivered on Monday, so I'm feeling a little better about it. I haven't had a garden in 20 years due to a couple of trees growing too tall and blocking the sun, but I took them down last year. Really looking forward to fresh, homegrown vegetables this year!

sean m_1
4/18/2009 2:57:33 PM

Reference last frost dates and the following comment --"You can choose between a 50/50 probability of frost after the given date, or you can play it safe and choose the 90 percent date, which means there’s only a 10 percent chance of a frost after that date"--- I believe 90% indicates the likelihood that a frost will occur after the specified date Thx

sean m_2
4/18/2009 2:57:00 PM

Reference last frost dates and the following comment --"You can choose between a 50/50 probability of frost after the given date, or you can play it safe and choose the 90 percent date, which means there’s only a 10 percent chance of a frost after that date"--- I believe 90% indicates the likelihood that a frost will occur after the specified date Thx

4/14/2009 12:26:23 PM

First Time Reader

4/9/2009 8:46:42 AM

What an amazing resource. I'm attempting a garden for the first time ever and I'm very excited to have found this site. Thank you! Also, thanks for the clarification on how to read the frost table. T'was a bit confusing.

Penny Reynolds_2
4/7/2009 5:22:00 AM

New to motherearth

3/29/2009 1:32:30 PM

there are two books that deal specifically with "companion planting" that many people recommend..... "Carrots Love Tomatoes" leans more toward vegetables and "Roses Love Garlic" follows-up for some of the more ornamental plants (flowers, etc.), but both cover some of each

3/29/2009 7:28:32 AM

I would like to learn more about "companion gardening"...which plants grow well next to eachother, etc

Jacqueline Jakle
3/28/2009 2:01:38 PM

This info is good to know. I live in Southern California and recently had to move to a very small place with absolutely no area for a garden. I want to grow lettuce, tomatoes, onions, garlic and herbs, and feel I should try containers but wonder about using either one of those year-round boxes, or a miniature version of a greenhouse. Thanks for any advice. Jacqueline

3/27/2009 9:27:48 PM


3/27/2009 12:15:43 PM

There is a sentence that is potentially confusing. The Frost/Freeze website's table shows the probability that the temperature will reach a given point after the date given. So, the 90 column means a 90% percent chance the temperature will get that cold after the date you are looking. Your statement says the opposite: "you can play it safe and choose the 90 percent date, which means there’s only a 10 percent chance of a frost after that date."

Misty Dawne
3/19/2009 2:25:42 PM

This page was very informative page. I just moved to a new area (Oklahoma) with a shorter growing season and found this article very helpful. I now have a new plot (2.5 acres less the house and the shop) to turn into an edible landscape. Happy Gardening! Thank you for sharing, Misty

Leonard M Rowe`
2/7/2009 1:42:02 PM

Thank you and looking for a good year. I love to can. Thank you Leonard [Larry]

1/18/2009 1:44:27 PM

Signing up for the first time...I am looking forward to having you as a reference...

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