I'm fairly certain cleome seeds need a cold period. If you search around, you'll see suggestions for keeping them in the fridge for a while. I wintersowed some while it was still quite cold out and they germinated quite well.

Thanks for your post! I am going to stratify some this week and try that. Yesterday I noticed that I have 1 cleome seedling! Have other sprouts coming up in flower bed but too early to tell, may be weeds. I don't know if these seedlings are from seeds sown in Fall or Spring. I am so excited!!

Cleome needs oscillating temperatures for germination.
Mine germinated under lights with turning the furnace down at night and lights off at night so they were going from about 60ºF to about 80ºF over the 24 hours.

I have literally hundreds of cleome seedlings coming up outside. They just reseed themselves for me!

Mine are in the fridge after reading to do that on the annuals forum. Two weeks was suggested. Mine will go outside on Wed. and I will see what happens. I realize I may be late trying this, but someone gave me the seeds and I wanted some very badly.
Susan.

I winter sowed cleome seeds back on February 26 and they sprouted April 17. That's nearly 2 full months in the milk jugs on the north side of my garage. I transferred them from the WS milk jugs to regular pots last weekend because they'd grown about 3" tall and had their second set of true leaves. I don't think I got great germination--there were only a few sprouts in each jug but they did germinate. They'll go in the ground as soon as the bed is prepared. With winter sowing you just sow them, set the jug outside and forget about them.

Mine started popping up six days after I put them out (after 2 weeks in fridge). I sowed them in peat trays.
Gardenweed, what are WS milk jugs? Also, could you explain the milk jug method to me, thanks.

I just bought some of these the other day from a local nursery. Pretty plant, but has anyone here noticed the similarity between their leaves and those of cannabis? whoa! I got a lot of wierd looks from family when I showed them off. ;)

I got three sturdy plants, good size, purple and red, and am so excited to watch them grow.

Kim

Susan, Winter sowing is a method of seed propagation using recycled plastic containers (milk jugs). This was my first year trying it and it works incredibly well. I only WS a few annuals--alyssum, cleome, nasturtium, cosmos, marigold & ageratum. I mostly WS perennial seeds, the bulk of which I received in trades. The seeds go inside the milk jugs and the jugs go outside in December/January/February/March. The seeds know when to germinate--it's in their genetic code. The milk jugs simply provide a sheltered environment where they can germinate without the risk of being blown or washed away and where critters can't get them.
Check out the winter sowing forum link at the top of the Propagation from Seed page. There's also a website, wintersown.org where you can read about it and even see lists of plants that are hardy in your zone that can be WS successfully. I'm growing over 40 new perennials from WS, including Siberian iris, Echinacea, balloon flower, butterfly bush, blackberry lily, flowering dogwood, turtlehead, bee balm, globeflower, beardtongue and many more. Setting the seeds outside in winter means the plants that grow are already accustomed to the fluctuating outside temperatures and don't need hardening off. I'm even growing tomatoes from seed this way. My tomato plants are huge and healthy way earlier than usual here in north central CT.
If you have questions after checking out the website, feel free to email me. I'll be glad to answer if I can.

I was surprised to see this post bumped up today! I was just thinking of it last night when I was transplanting some of my cleome. When I said I have literally hundreds coming up, that is what I mean too! The seed has been spread by wind, birds, etc. into my garden and some are as big as my tomato plants! (About a foot tall.) I think this is the third year for them. Just amazing what Mother Nature can do! Wish everyone was closer and I'd gladly give you dozens. I do love this plant, but don't like it taking over everything either.

Gardenweed, thanks so much, I did go and read the information. I am excited about trying it. I had no idea tomatoes could be winter sowed. This is so interesting to learn about and will be fun to do some things in the winter too.
Soinspired, I love these plants too. Hope mine that have come up will reseed this winter.
Susan.

I also started some from seeds, i didnt know about the cooling off part so i didnt do that,i have them planted in 2 diff. places, both with lots of morning and late afternoon sun..its been almost 2 weeks ,and nothing yet...so i just keep watering the dirt!! LOL!

Update - I repotted my tallest cleome seedling today. It had grown to 14" tall in a quart pot so it went in a gallon pot until I decide where I want to plant it. There's plenty of space--I'm just trying to make certain I plant it beside something that blooms in a companion color. I combined the rest in gallon pots. They're still only about 6" tall but they're strong plants.
dancingmoons - last year I did what you're doing. I just kept watering the dirt where I DS the seeds... kept the weeds happy anyway. Thanks to winter sowing, I've got actual plants this year.
BTW - I'm in north central CT about 2 miles south of the MA state line.

Here's pics of all the cleome that came up as volunteers. Somewhere in there I have tomato and pepper plants!
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And, these I transplanted around a tree.
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They are just beautiful! I'm so proud...

I love cleomes, I have mine in the freezer and hopefully they will sprout for me. I have grown them down here several times and just love them. although I can never find seeds to any other color other than pink. If anyone out there has the deeper colors such as purple, I would love to trade. I will definately go to the seed exchange after this. by the way, I just love those pix above and I am so jealous of you. I do love to see volunteer plants. Josie

riograndegal - Hazzard's Greenhouse has lots of cleome seed types for sale including a plum color and a lavender. You could buy seeds then trade what you don't need/use (they sell in bulk). I ordered from them last winter and the seeds arrived in a matter of days from when I placed the order.

These are new to me , and I look forward to trying them out in the Post Oak Savannah of Texas this coming Spring. Thank you guys for all the valuable info on these beauties.
LtlWilli~Rick