When Is It Safe To Plant?


image: FarmersAlmanac

 
When is it safe to plant garden vegetables? Is it simply after the last frost date for your area? And if that’s correct, then how do you find out when is that last Spring frost date?

Can you plant some vegetable crops before the last frost date?


 
The Farmers Almanac defines the following frost/freeze categories:

LIGHT FREEZE:
29°F to 32°F—tender plants killed, with little destructive effect on other vegetation.

MODERATE FREEZE:
25°F to 28°F—widely destructive effect on most vegetation, with heavy damage to fruit blossoms and tender and semi-hardy plants.

SEVERE FREEZE:
24°F and colder—damage to most plants.

 
To find the normal average date of your last frost, use the following calculator while simply entering your zip code (or city, state) (source: Almanac.com).

Frost Dates Calculator

Note: There is often a very wide variation from year-to-year at any given location regarding the last spring frost/freeze date.

 
To discover what’s going on right now, here is the current live weather map of any frost/freeze outlook for the United States:

http://www.intellicast.com/National/Temperature/FrostFreeze.aspx

 
Soil temperature probe:
Dial Soil Thermometer, 6″ Stainless Steel Stem, 3″ Dial Display

 

Cool Season Vegetable Garden Crops

Found this list of vegetables on motherearthnews.com,

Safe to plant very early spring

onion
peas
spinach

Safe to plant early spring

lettuce
beets
carrots
radishes
dill
cilantro
cabbage
broccoli
celery
kale
potatoes

Plant after last frost

beans
corn
melons
cucumbers
squash
tomatoes
peppers
pumpkins
eggplant
basil

 
What has been your experience with planting near or even before the supposed last frost date? How often has that worked out for you?

38 Comments

  1. Most State University Ag centers have planting guides that can be saved to your PC or printed off.

    A number of years ago, I found a Freeze/Frost data document developed in 1988 by the NOAA. I’ve found it to be very useful in determining when to plant. It’s 206 pages and covers most areas of every state. Here’s the link. You only need to print off the pages for your area.

    http://www.crh.noaa.gov/Image/oun/climate/freeze/freezefrost.pdf

    Planting early to get a jump on the season is easy. Plant seeds in trays and keep them indoors, or in a green house if you have one, until you can transplant them outside after the average last killing frost days. You can use the above document to determine your odds from 28 to 36 degrees. We plant tomatoes, hot peppers, bell peppers, eggplants in January and keep them in pots/flats in the green house until they are ready to transplant.

    Some things like Okra, Snap beans and Purple hull peas are best planted in the ground well AFTER the last average frost date for your area. Light frost generally starts forming around 35 degrees but I’ve seen it form at temperatures as high as 40 degrees depending on the dew point, wind speed, cloud cover etc… It’s rare, but it has happened. We usually set out our tomato plants two weeks before the date when the last killing frost is 10 percent at 36 degrees.

    None of this is 100 percent accurate but it will get you in the ball park. Stock up on wire hoops and garden row covering material just in case you have to rush out and cover your rows the day before an announced late frost or freeze.

    1. Thanks for the info CrabbeNebulae. That is allot of reading. I downloaded it and will read as I have time. It is too many pages for me to print, but I might pull out what is valid for my area and print.

  2. I have been using the Wyoming Interactive Last Frost Map. According to it, our last frost is usually between June 1 and June 10. Last year it was way earlier, though.

    I have radishes and peas sprouting already and my rhubarb is going strong. I have also planted carrots, Potatoes, beets, turnips, pak choi, fennel, kohlrabi, broccoli, spinach, thyme, & parsley. I have had volunteer scallions coming up for a few weeks now. I didn’t plant them this year or last, so those must be from two years ago.

    We are supposed to get into the 80’s by this weekend. I MAY start planting SOME beans, squash, corn, cukes, etc a week or two before June 1 and keep them covered at night. Tomatoes, peppers, melons, etc really need to wait until June.

    Only one of the seven blueberries I planted last year survived the winter.

    1. I forgot to mention that the Wyoming Last Frost Map has links to the same info for adjoining states.

  3. Ha ha, love it, black tomatoes. My green thumb only seems to be able to grow mold and mildew in our bathroom. Ha ha.

    Actually the only crops I seem to have ever had good success with are the early plants like snow peas, etc. Never had luck with tomatoes. I am not a big tomato fan anyway. DH loves them. Although I don’t mind tomato sauce.

  4. We have a last frost date of June 7, but the 2 weeks prior, some of the hardier things go out. All of the old-timers watch the snowline on the mountain overlooking town. When it reaches a certain elevation, it’s safe to plant.

    One thing I have been learning about is micro-climates. Even just around the yard, plants will grow differently depending on what they prefer. Will they thrive with the heat radiating from the house, or will it burn them? Do they thrive with morning light or afternoon light? Even if they are supposed to get “full sun”, does shade cloth protect from the intensity of the sun here at 7500′ or do they want the intensity? Do they need to be in an alcove that is protected from the dry wind? Each kind of plant seems to have it’s​ own special needs. I am far from having it all figured out, but I learn a little more every season. I agree completely with NRP, get gardening knowledge and experience now.

    1. This year I’m doing some planting in the shade of my trees. They’ll have good sun until the trees are fully leafed out, then partial sun the rest of the season and some protection from the heat. Last year the things I did this with as a test survived the first few frosts of the winter because of the leaves on the trees and produced as normal. I’m testing it this year with tomatoes.

      You’re right, every plant has its own special requirements. I’m also planting celery on the north side of the house this year. Previous years it’s died as soon as the real heat hit.

  5. Howdy,,
    So yall are concerned with freezing etc,
    Thats just one of the issues with growing food,
    in theory we have year round growing conditions here, but we got over 10 inches of rain over the last 3 days here at the farm, even the cover crops took a beating,
    Point is, rain is just as if not more damaging than anything else, im just glad i wasnt trying to grow anything at the moment other than cover crops, on saturday we had a few downpours that would have destroyed everything, even my sudan grass growing in the carrot field is flat,
    Everything has a down side

    1. @ Nailbanger

      Dude, 10 inches of rain in 3 days????

      Here I get about 10 inches of rain a YEAR!!!!!

      NRP

      1. Yea, i know, and its raining outside as im punching this in,,,,
        And radar shows a mass of heavy showers headed straight at us.
        Not sure whats worse, being a farmer in this or trying to paint rafters for the house im working on, either way i aint makin much progress…..
        Better than no rain though, guess ill be building doors in the shop today,,,

  6. This topic is discussed frequently at my house.
    I remember my dad for ‘decades’ never even turned the soil until school was out-May 30, and planted first week of June.

    We are spoiled with ‘global warming’ now.:-)

  7. May 24 is the “official” last frost date around here. I see scores of people rushing a week prior to that putting their plants into the gardens. They seem to forget that Mother Nature does her own thing. I usually wait another full week after the 24th before I attempt planting my warm weather crops.

    I should be able to plant the cool weather plants now but it’s been pouring rain so much that the soil is nothing but mud. Hoping that once the soil dries out that it doesn’t go straight into scorching temps.

    My ex-mother-in-law would plant at the beginning of April just like she did back in Europe, and of course, everything would die.

    Hoping that this year, we’ll have the summer weather we should be having….but only if Mother Nature co-operates.

  8. When is it safe to plant? Historically, in your region, when does summer vacation for schools begin? Historically, public schools let out for the summer “vacation” so the kids could help with the planting, care, and harvest of the crops. Education could wait until the planting, growing, and harvest was done.

    Summer vacation for school kids is a relic of those days. Many are pushing to scrap it for compulsory year round school schooling.

    Trust your agrarian ancestors.

  9. Here in Middle Tennessee the old timers say April 15th is ok for the tomato’s etc. However in one of my past lives in the 80’s we had a hard freeze on April 26th. We have here in our area what are called Redbud Winter, Dogwood Winter, Locust Winter and Blackberry Winter. Named because these plants or trees are blooming at the time of the cold spell. This typically holds pretty true. This would be a little different for the west and east parts of the state.

    1. We just had a spell already of Dogwood/Blackberry Winter, and another round coming in within the next two days.. Blackberries are in full bloom..and have been for over a week. low tonight supposed to be about 50.
      These are the tips from and thru family interactions thru the year, zone 7a-b, depending on elevation…we practiced these as I grew up and helped either willingly or not in the garden.
      Traditonally the earliest we plant above the ground crops is Easter.
      With potatoes planted at first opportunity in early March, and dug by mid June..No July rains to hit the potatoes or they will rot in the ground.
      Those things that require warm soil, like pepeprs and tomatoes, usually have ready to transplant by Mothers Day.
      Corn should be Knee-high by the 4th of July.
      Weather changes have been evident, This year and last year/ too much rain too close together to even work the land. Alternate planting methods are in use by some/and on some items..by many who can’t keep their fingers out of growth cycles of things…a few raised beds and containers helps replace the digging…and extra soil additives help with the growth of additional beds. Some in the area are fortunate to have more sand in the soil than others and they have some things planted, but those with red clay…uuummm not so much.

  10. To Skibum:

    Yes, You can create your own microclimates using shadecloth and hoops or wood supports. I did this on a small scale in my old California backyard where I built 3 shades next to each other and placed container plants around the bases. Daytime temps could be higher than 100 degrees for long periods of time so I wanted to create an oasis from the heat. I placed these shades in a location that would augment to existing sycamore tree in the backyard and provide shade in areas that were blasted by sunlight in the hottest part of the day. This area was surrounded by fences or a wall to protect from harsh winds. Add a little water to the plants each day and the area flourished. I grew tomatoes, cucumbers and squash back there. Me and my wife grew phlox and dianthus in containers. That yard we had a climbing rose bush (Banksian- yellow) that covered part of the concrete wall around our cul-de-sac.

    In my new location, I use Memorial day as a reminder that you better get things planted. Easter is my reminder to prepare my soil. First of May, I can transplant. Each year my timeline is different in that I am limited by my allergies to tree and shrub pollen. When I can go outside without a big box of tissues, this is when I start to work hard in my yard. If the plants are a bit slow in growth, I would augment some of the water with Miracle Grow or some other fertilizer that goes into solution when you add water.

    Good luck to all in your yards this year. We all seem to garden on this site. Some to grow food, others to recharge the soul. Many do it for both purposes. I also try to promote a pesticide free yard because I am surrounded by many that use pesticides. I like to hear the sounds of bees buzzing within my yard.

    1. Thanks! I’ve been shading the tender greens and cukes, “hot housing” the chile peppers with plastic sheeting over pvc pipes, the asparagus loves being on the irrigation ditch, the peas prefer morning sunlight and afternoon shade, the tomatoes love the warmth of the house, and on and on. At the house, we mostly have the perennials (strawberries, blueberries, hops, sage, lavender, tarragon, mint, asparagus, parsley, Jerusalem artichokes) with a few annuals that we harvest often, like the lettuce pots that I snip every time I make a sandwich or salad, some of which will reseed itself. At the community garden, we do most of the annuals. Even though it is only a couple of blocks away, the growing season there is two weeks longer on both ends of the season. I’m trying to dial in companion plants and have different beds with differing water and nutrition needs. I’ve been doing this for several years, and every season is a learning experience.

      Yes, both our yard and the community garden are pesticide free. We have plenty of plants that are there not only for their beauty or utility, but also for the bees, butterflies, and birds. I am especially excited for the fruit trees that we will be receiving at the community garden this year! And gardening is cheaper than therapy, plus you get tomatoes!!!

  11. I just plant whenever and protect everything. I always have seeds to replant if something dies, but so far anything grown from my own seeds seems pretty hardy. I did get six tomatoes from someone else this year, and one of them apparently doesn’t like my yard and is willing to die to escape. It looked great Sunday morning and by afternoon it was wilting badly. Not sure the reason on that one. All the others look fine. They’ve been in the ground for about two weeks now.

    It occurred to me this week that by doing it this way I’ve probably been unconsciously (accidentally) selecting for cold hardiness.

  12. We are in grow zone 6 but live in a canyon at 2000′ elevation and have lived in this spot only 3 1/2 years so we are still learning the climate conditions at our particular location . Right now we get a breeze off the mountain snowfields that is pretty cool and our last frost is usually in late April but has happened in late May also. This year we have a bigger than normal snowpack so we will probably not plant till late May .
    Last July we had a hail storm that put little black spots on apples and peaches .They were still edible just not pretty.That was very unusual and hopefully won’t happen again . Yet we ate garden fresh green beans the next week,go figure.
    We do look for cold hardy plants and talk to as many old timers as possible to educate ourselves .

  13. The old farmer who use to own our land said not to plant until you could no longer see snow on the distant mountain tops. Listen to the old timers, they’ve been there and done that for a living. The experts(?) are calling for high of 80 this Thursday.

  14. my tomatoes won’t go out until sometime this week or next. I always plant in walls of water and even if we have a freeze, which we have had a lot in May, they keep them warm down to 15 degrees. My last freeze date is June 7th and Sept is the first freeze, that doesn’t grow much. I cover cold crops with milk jugs and others with clear plastic bottles with the top off. We had 80 degrees in April, like NPR, live south of him but higher up, and then had 2 inches of snow this weekend. Today it was in the high 70’s! None of this hurt my lettuce, some hardy plants.

    1. @ old lady

      A little off subject, I want to thank you for the VERY VERY best recipe for Bisquits. I replaced 1/2 C of flour w/ 1/2 C wheat. I make a batch evert Saturday. Only bread,ish I eat anymore. Thank you, Thank you.

      NRP

      1. @NRP and old lady,

        I missed the biscuit recipe :( Would you mind sharing again? Thanks!

        luv Ya’ll, Beach’n

        1. @ Beach’n

          Found the original post from old lady;

          old lady says:

          December 27, 2016 at 9:15 PM

          I just put the whole recipe out and it went away! So here again

          2 cups flour
          1 tesp salt
          1 heaping tesp baking powder
          1/2 teap baking soda
          put above in bowl and add
          1/2 cup butter – soft or melted, mix lightly
          add
          1 cup buttermilk, mix lightly
          if you have it add a handful or 2 of shredded cheese and mix.

          turn out on floured surface and knead about 6 or 7 times
          cut with sharp biscuit cutter
          put on baking stone (love my baking stone)or cookie sheet or in a dutch oven
          bake 12-14 min at 450 degrees
          slather with butter, jam, or a tomato or ….
          makes about 10

          Really Really good
          NRP

          PS; I got one of these…. Lodge L7B3 Cast Iron Drop Biscuit Pan, Pre-Seasoned …. it works FANTASTIC

        2. Thank you all for the accolades! My husband loves them and they work well in dutch oven with coals. Instead of adding bacon and eggs, we eat them with homemade jam with butter of course, or a fresh home grown tomato slice. Then the next day we have Shepherd McBiscuits. This is a version of MCD’s with egg, sausage and or bacon and sometimes cheese.

        3. @ old lady

          ‘accolades’ ???? that’s a mighty big word to be using around this old-fart ya know… HAHAHA

          Actually had to look that-en up.

          I still might suggest changing out 1/2 cup of white flour with wheat flour, reallyyyyyyyy gooders.

          NRP

          PS; had a couple tonight for dinner… and Blue likes the left-overs :-)

  15. Generally around here the 3rd wk of may is the last frost and the standard planting time. We usually get out first fall frost late Sept or early Oct.

    I try to rush things because of cabin fever and the gardening itch, most of the time it works out. Last year I showed restraint and put out my tomatoes May 21st, like I was suppose to, two days later it froze hard only one survived(they had milk jugs over them) I grow all my own seedlings so I had extra to put in for the dead ones. I plant extra for my BIL but he decided not to put in a garden at the last minute, so lucky for me.

    After 30+yrs of gardening I’m still learning. Love this site for all the great ideas and opinions.

  16. I think our last frost is about June 10-15. but of course most things can go in ahead of that. The old times have several tests of when to start planting. First is when the leaves start coming out on the trees & the other is when you can sit comfortably with a bare bottom on the soil. Never tried the last but the 1st is fairly reliable. Of course tomatoes, peppers & other delicates need to wait. We have a great variability in our spring weather. I remember when we kept bees & they would arrive about April 20 & we could have anything from blizzard conditions to it being so hot we had to hive them at night. So interesting gardening on the Canadian prairies.

  17. NRP
    Sorry to hear about your black thumb tomatoes :-(.

    This will qualify under planting to early which you did, so you could get a jump on the growing season. You must have missed the information I had written a while back for keeping your tomatoes healthy & green.
    My dad called them ‘hot caps’, we constructed them from newspaper.

    Lay 3-4 sheets of newspaper out flat, fold one corner to the center bottom edge, then fold the other corner over that section which will create a seam. Looks like a ‘triangle’ at this point. Now fold up the bottom edges to make an upward seem(like cuffed pants of old).

    When you have nights that the temperature will drop down & damage your plants put these over your plants. In order to hold them in place use your soil in the planter boxes or use rocks, bricks, which will be laid on the seams you created. These hot caps hold the soils heat inside to prevent frost or cold temperatures from damaging your plants. **Ti-pi for your plants.**

    If you use a plastic container, make sure you sink it down into the soil to prevent heat loss with that type of material.

    These all have to be placed on the plants before sunset to hold the heat inside your ready made mini hot houses. Go back to the drawing board you can do it, all it takes is patience..right? We will get that black tomato thumb green yet.

    1. @ Antique Collector

      I will give it a try, but not sure anything will work so well at 24 deg… HAHAHA

      Might have just a little early. :-(

      NRP

  18. Those you know with the Verticillium Wilt, there are charts of susceptible and immune plants categorized —bush, tree, and flowers.
    I just discarded a month old butterfly bush and replaced it with a rhododendron($4 at WM..:-)).
    The contaminated spot is a 3 X 3 space where I removed a diseased knock out rose bush that took 2 years to die.
    Hope this helps someone when purchasing.

  19. You can plant year round with row covers and greenhouses. There’s a farmer out of new hampshire that farms year round. hardy cold tolerant stuff in the winter under row covers. In east texas, we’ve had fresh tomatoes and other veggies at christmas dinner. We set up tall stakes in the garden and draped cloth across to protect them from sub freezing temps and frost. gotta use cloth if there’s a chance of contact with the plant. plastic is ok if you keep it off the plants. a few clothespins to secure sheets to each other and the fence are helpful.
    As far as spring planting, as soon as the chance of frost is past for plants. a little earlier for long germinating seeds.

  20. It would take a lot of intervention to plant year round where I live. The -30 and-40 is really hard to combat unless you are heating the greenhouse 24/7. Sometimes I wish I could have a longer growing season but too old to move!

  21. Hi Ken and other posters – thanks there is some good information in here that will come in handy.

    Ken I was curious. Does a frost always kills plants that are in the ground already or do some survive? Do seedlings survive frost any better than more developed plants?

    1. Seedlings are actually much more fragile than established plants. Frost that would barely touch an established plant will often kill a seedling. They need that established root system to survive.

      A few weeks ago I had frost hit my tomatoes–I ran out of wall-o-water, so several of them were unprotected. They frost-killed, but just to check I left one of the “dead” plants in the ground. It’s come back from the base and is quickly catching up with the others. Peppers, on the other hand, will not come back because their root nodes are all exposed. Plants with their primary leaves deep in the ground seem to have the best response.

      1. Very interesting response – Thanks. I like planting corn and various types of squash the most. What is your experience with those and frost? What is the best time to plant them do you think?

        1. Squashes and corn are warm season annuals and don’t handle frost well. The general rule there is to plant seeds in the ground after or just before the last frost date for your area–assume they’ll be up within a week to two weeks. I plant squash about a month before the last frost date but I have extra seeds if they die and I’m ready to protect them if frost threatens.

          If the weather doesn’t cooperate, that extra month can give me the edge between a good harvest and nothing. Once established, squash nodes can be buried in soil to give the plant an extra chance to survive.

          I planted corn early this year and the ground was so wet that the seeds all rotted. I guess that six inch layer of mulch has its drawbacks…

        2. I find getting the balance on my mulch particularly tricky too.Thanks for the great advice. Having a vegetable plot is fun but a lot of work too. I do like the way it saves money and sure is some wholesome eats too. By the way. I have a fishing blog myself. let me know if you maybe want to exchange some guest posts. Take care and thanks again for the advice.

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