Average last frost

joandaugh(Z5 Chicago)March 6, 2005

This is my first spring in my first house and I've been stockpiling seeds. How much longer do I have to wait!! :) Seriously, what is a good rule of thumb for figuring out when it's safe to plant some of these directly into the ground? I've got violets and forget-me-nots I'm hoping to plant as soon as I can; others can wait a while.

It was SO nice to play around in the yard today but I hear more snow is coming. I guess I'll have to content myself with starting some seeds indoors.

I'm so glad to have found this forum--I've been on several others here for a while but didn't think about looking specifically for a Midwest board. Duh.

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Hi Joan...yes, today was a beautiful day..but I hear rain and snow, too..sigh.
The official sowing date for Chicago and burbs is May 15th.
If you have room, start some indoors..it's too early for zennia's/marigolds, they germinate within days..Read directions on packages and see which say 6-8 wks before planting time..Good luck, and congrats on your new home..Toni

    Bookmark   March 7, 2005 at 1:02AM
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joandaugh(Z5 Chicago)

May 15th!! Yikes, I don't think I'll last that long. I fell asleep on my gardening books last night. Where do you typically find the official date, or is it always about May 15 for the Chicago area? So basically I should subtract the estimated weeks on the backs of the packets from May 15 to find indoors start dates. I can start some in my greenhouse, which I haven't used much yet. It's pretty rudimentary but it does have a heater with a thermostat (jacked up my utility bills) and fans. I think I can hang a shop light for seeds too. I guess that will have to do.


    Bookmark   March 8, 2005 at 2:52PM
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I fall asleep on mine on a nightly basis! LOL!

I'm from zone 9. I would have had bareroots in the ground already and things are blooming like crazy back home. My body clock says that it's SPRING even though the thermometer outside tonight says that it's a balmy 31 degrees right now. :P

How lovely to have a greehouse! We end up staying in this burg and I'll betcha that I'll have one myself next winter. I'm used to year 'round gardening. The only thing dormant in my world back there were a few deciduous trees and my wisteria. Everything else was always cooking...

I'm going to CA in a few weeks for a Spring fix. Maybe my Mother will let me dig in HER dirt! LOL She's already PLANTED TOMATOES! @@

    Bookmark   March 8, 2005 at 9:34PM
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RexAnne(z5 Chicago)

May 15th! Yikes is right. I plant peas on St Patty's Day.

    Bookmark   March 8, 2005 at 11:31PM
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Joan, u ask where I get the dates? I know, I'm in a hurry too..lol. I get a ton of catalogs and in most they'll have a zone map and planting times. Also, some seed packets (on the back) will display dates.
What's ironic is, about 8 yrs ago, planting time in Chicago was Apr 15th, then for some reason they changed it to May 15th. That's a whole month!!
Some plants, like petunia and geranium, should be sowed in Jan, while other quick growing plants like marigolds and zennia's much later. I like starting vines like Morning Glory and Moonflower early...even after soaking overnight and knicking each seed, they take a while to germinate.
Smom, why did u move from z9 to z5? LOL..I'd like to reverse that situation, speaking of myself of course.
I kill myself trying to grow 400 tropicals, overwinter in particular. Dry heat, little sun. I keep humidifers, indoor fountains, fans running on low, lighting, misting..this keeps me busy in winter. Citrus is my vise. I luv them. Keeping them overwinter is a project though. For those who are like me and miss getting your hands dirty, buy tropicals. Though I do not feed 99% in winter, I take many to sink and shower, and hose away..I also use Superthrive, a hormone/vitamin stimulant, that's applied once a month. But it's worth every aching minute. LOL. It's also great seeing flowers in Dec-Jan, and fruits throughout the yr. I've got 2 more citrus coming in as soon as weather permits, if it does..like I said, my vise.
Anyway, check your seed packets..I can't recall which company's have the charts on back. Or look in catalogs..It's a bit more complicated now, since they've come out dividing zones..like 5a and 5b..lol, what next..
As much as I hate winter, I have to admit the winter's have been much more milder than say 10 yrs ago..and we sure don't get as much snow as we did. Even though snow is the best natural mulch..Toni

    Bookmark   March 9, 2005 at 11:14PM
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joandaugh(Z5 Chicago)

I noticed in one of the books I have--one of the "Gardening Month By Month in Illinois" books--they use May 15th as the sowing date for most things. I was reading it over to see if there are some things I can be working on now (aside from cleaning tools & stuff).

I was also reading about winter sowing somewhere else on this forum and that sounds really interesting; sowing in plastic containers that are ventilated and kept outside, even throughout freezes. Hmmmmmmmm . . .

    Bookmark   March 10, 2005 at 9:38AM
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The Chicago last frost is usually april 15th.

    Bookmark   March 12, 2005 at 12:17AM
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Chittown, Apr 15th was the official date for sowing, but they changed it to May 15th in the last few yrs. As much as I'd love sowing in Apr, I sure wouldn't want my newly planted seeds destroyed by a late Apr snow blizzard. Heck, we even have snow in May..not much but sometimes, enough that would kill newly planted seed that needs warmth to germinate. Toni

    Bookmark   March 12, 2005 at 12:54AM
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tropicanarama(Chicago 5b)

You gotta pretty much stick to the May 15 date these days. The average low around April 15 is only 37 according to weather.com, and the mean temp is like 42 - that's really, really pushing it for seedlings, and one dip below the AVERAGE means all your hard work is ruined. I've put a chart below so you can see the yearly average & record highs and lows - you'll see that even in late April/early May, that green line dips dangerously near/below the dreaded frost line. (Some people wait til Memorial Day to be on the safe side!)

BUT... you have plenty of options for starting seeds now. We're just about 9 weeks out. You can certainly plant things that require 8-10 weeks to transplant:
- Vinca
- Impatiens
- Petunias
- Moss roses
- Verbena
- Gazania
- Cleome
- Thyme

and, if you plan on hardening off for a week or so in a frost-protected place like an enclosed porch, you can plant the 8-week stuff this weekend - here's on my seed starting list for today:
- Ageratum
- Bachelor's buttons
- Four o'clocks
- Nicotiana
- Snapdragons
- Alyssum
- Celosia
- Dahlias
- Dianthus
- Evening Primrose
- Hollyhocks
- Penstemon
- Poppies
- Malva
- Nigella
- Melampodium
- Rose Campion
- Heliotrope
- Tomatoes, eggplants, peppers (use peat pots - they get big fast)
- Coleus

Hold out another two weeks to plant the 6-week stuff:
- Morning Glories
- Moonflower
- Scabiosa
- Sweet William
- Stock
- Amaranth
- penstemon

and maybe wait even three or four weeks more to start:
- cucumbers (peat pots for sure)
- cosmos
- marigolds
- zinnias
- calendula/pot marigolds
- dill

...So I guess all of which goes to say, if you're jonesing to plant now, you can - just grow some new varieties.

And if you can't STAND holding out, check out the winter sowing forum. It's very reassuring to do low-maintenance gardening when it's snowing out, like today! Plus... think about planting some of those crops that need direct sowing as early as possible, like sweet peas and radishes. You can get those into the Actual Yard by April 1 - that'll make you feel better too!

Good luck, and let me know if you want to trade seedlings here in Chicago :)


Here is a link that might be useful: Chicago weather averages

    Bookmark   March 12, 2005 at 8:24AM
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Paulice(4/5 N. Ill)

The main thing to learn about spring planting is what plants are tough and which are tender relative to cold. We regularly set out lettuce and the cole plants as well as violas and pot marigolds in mid April. Sometimes earlier if the 10 day forecast looks good.

Tomatoes, peppers, eggplant, basil have to wait until the third or even fourth week of May. Various other annuals fall in between: Lobelia, petunias, verbena, alyssum.

A whole lot of it is keeping records and paying attention to the 10-15 day forecasts. As bad as frost is on some of the annuals, cool wet weather in the 40's and 50's causes bad problems for the cucumbers, squash, gomphrena, eggplants.

    Bookmark   March 12, 2005 at 12:31PM
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joandaugh(Z5 Chicago)

Kristen--thanks for the extensive list. I think I'll start a calendar checklist with what you posted.

One way I always remind myself about Chicago "spring" is that I went into the hospital to have my youngest on April 20th and it was cold, miserable, you could still see your breath during the day. Came out 2 days later and it was practically tropical. I never know whether it's safe to plan his birthday outside or not. I can make myself wait to plant outside until May 15. Good thing it's a Sunday!

I am from Seattle so I'm not used to Chicago springs, even after almost 15 years.

    Bookmark   March 12, 2005 at 2:05PM
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RexAnne(z5 Chicago)

excerpted from the University of Illinois Extension Spring Gardening Packet

""Near Lake Michigan, the frost-free date is usually considered to be April 25. Somewhere between one and three miles from the lake and out to Interstate 294, the frost-free date is May 1. West and south of Interstate 294, the frost-free date is May 5."

Plants that can be planted on or before the frost-free date have to be cold-hardy, plants that can tolerate frost and even some freezing weather. Plants that are tender or warm-weather plants should not be planted until three weeks after the frost-free date. Even waiting three weeks after the frost-free date allows for about a 5 percent chance of frost.

Vegetables that are frost-resistant include: leaf lettuce, onions, peas, spinach, Irish potatoes, Brussels sprouts, cabbage, cauliflower, broccoli, carrots and radishes.

Examples of annual flowers that tolerate frost are: alyssum, pansies, violas, flower kale/cabbage, snapdragons, straw flowers, calendula, cornflower and dusty miller. "

I planted peas yesterday plan on getting the spinich in tomarrow (should gotten out there last weekend) Purple Orach is coming up all over the place.


Here is a link that might be useful: read all of it here

    Bookmark   March 19, 2005 at 7:59PM
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How can they just deicde to change it a whole month? Thats ridiculous. Chicago might have gotten snow in the past in may, but that would pretty much associate with record lows and record snowfall. You can't base your life on record lows, otherwise we would all be planting zone 4 plants in our yards. Many other sources say Chicago's last frost is Between April 15th and May 1st. The earliest frost Chicago, IL (Meigs Field) ever recorded was March 4th. May 15th's record low is 40F. Chicago O'hares record last frost is also May 4th.

    Bookmark   March 20, 2005 at 1:16PM
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mrmorton(z5 IL)

Honestly, the only frost date I have ever known is May 15th. It is wise to stick to this date. I work for a landscape company that plants thousands of annual flowers in and around Chicagoland every year. We have lost innumerable amounts of flowers due to sudden cold weather in mid to late May. We even have clients who tell us to wait until after Memorial day to plant their annuals.
By all means, go ahead and plant cold hardy annuals like Pansy, Viola, etc. Just be wary of jumping the gun on warm season plants.

    Bookmark   March 21, 2005 at 5:01PM
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Joan, I checked out your member page and the link to your homepage, and your link to the Roycemore school makes me think that you live up in my neck of the woods--and that if you're anywhere near as close to the lake as I am, I don't think you have to completely abide by that May 15 thing. I generally trust that as soon as the days start hitting 50, Lake Michigan saves me from freezing night temps. I'm usually pretty confident about ordering mail-order plants for April 15 delivery, and that's usually about the time I start hardening off seedlings I've started indoors--though I'm prepared to yank them all back into the basement on a moment's notice probably through early May.

I wouldn't go and try to sow a warmth-loving veggie or annual directly into the garden now, but a lot of things like violets etc. I wouldn't be all that concerned about--and you always have the option of throwing a styrofoam box or something over young seedlings if you get a surprise cold snap. Plus, having a greenhouse ought to open up your options considerably!

    Bookmark   March 21, 2005 at 7:07PM
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tadeusz5(z5 il)

MrMorton; I agree with you; I have lost annuals before May 15th, but the cold varities are no problem-

I have planted Viola's, Pansies ,and Dianthus into my garden $9.90 a flat of 48. Always trying to beat the last of winter.

    Bookmark   March 21, 2005 at 8:37PM
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joandaugh(Z5 Chicago)

All my belly-aching and I haven't had time to start much anyway. Instead, I can't stop buying seeds. I really appreciate all of the input. I'm taking a week off at the beginning of April and I hope the weather's decent enough so I can at least get things ready. I want to build a small herb garden in back and a small raised garden in front of the house so I have lots of prep to do. I figured that should keep my mind off of putting plants out too soon. I'm a little farther from the lake than Evanston so I'll wait a while for most of my planting/sowing. I'd rather be safe than sorry. I'll just consider it an exercise in character building.

    Bookmark   March 22, 2005 at 11:52AM
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I was wondering the same thing. I am in the chicago suburbs and I bought some bulbs. Some of the bulbs have shoots coming out of them. Can I plant them before April 15th? Or should I wait?

    Bookmark   March 20, 2010 at 6:18AM
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joandaugh(Z5 Chicago)

Well, in 5 years I have learned to try to wait until Mother's Day to plant things outside if you don't want to lose them. If you have bulbs that are sprouting, you probably want to plant them in pots and keep them in your house if you can. After they've bloomed and after their leaves have turned brown or yellow, stop watering them and put them in a closet or a basement or a cabinet with little light. In the fall, plant them where you want them to come up next spring.

It does depend on the kind of bulb but that's the general idea. I suppose you can still put them in the ground any time after April 15th. The dark closet method lets them rest to store up energy. As you can tell since it's snowing today (boo), it's still really unpredictable in this area. I say pot them and and enjoy them inside!

    Bookmark   March 20, 2010 at 11:50AM
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Hey Joan, I got a little crazy when I was looking at bulbs and bought a 200!! I dont think I have enough pots for that..I do have them up in the attic to keep them cool..Maybe I will try and plant a few in a pot and see how they do! Ive never done pots with bulbs..but it is worth a try!

    Bookmark   March 20, 2010 at 11:49PM
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joandaugh(Z5 Chicago)

OH! It would probably help to know what kind of bulbs you got then. I just got pots from Home Depot this weekend that have bulbs in them and were fine outside in the snow; I set the pots on my front stairs. They are tulips and hyacinth, about 5 or 6 bulbs in a 12" pot. So you could group yours but you'd still needs lots of pots. Maybe it's just worth a try putting them straight into the ground and fending off the squirrels.

    Bookmark   March 22, 2010 at 2:20PM
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