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Winter Sowers' Advice

October 25, 2018

I Iive just outside Boulder. As a winter sower in Colorado, what advice do you have for a newbie?

Comments (24)

  • treebarb Z5 Denver


    To view previous RMG posts on winter sowing, go to the top of the page to the search box and type in Winter sowing. Click on winter sowing in Rocky Mountain Gardening and 341 previous posts come up on the topic. There's been some really good info posted on winter sowing here over the years.


  • lizbest1

    Pretty much any perennial that will grow in your zone can be winter sown, Pentstemons and things that need cold stratification do particularly well. Don't forget to put holes in the bottom of your containers for bottom watering, I did that the first year! Not easy to put them in after the soil and seeds are in!

  • smdmt

    Thanks for your responses. Treebarb, I can not find the RMG winter sowing questions. the search comes up with 104 and they are all over the board. Some are not even related to gardening.

  • treebarb Z5 Denver

    You're right, smdmt! The first 10 posts or so are on winter sowing, then it goes into other topics. I'm sorry!

    Are you wanting to sow something in particular or just the process in general?

  • Skybird - z5, Denver, Colorado

    Looks to me like the houzz search engine isn't very effective! Here are links to some of the winter sowing threads I had saved in bookmarks--I don't see most of these in the search results!

    This first one is from '08/'09 when we were all just getting interested in it! HighAlt (from Silt!) is the one who got us all started, and she hasn't posted on RMG for many years now! These threads are some of the LONG ones--probably more than you ever wanted to know, but you should find answers to just about any questions you may have.


    Wintersowing 2010


    Wintersowing 2011


    Wintersowing 2012


    When I started doing it I was doing it in small flats, putting several different types of seeds in each flat, but doing it that way meant that when the seedlings came up they needed to be separated and transplanted into small pots and I tended to not get that done! Now when I get around to doing it--I really don't have anywhere to plant more things!--I put the seeds into 8 oz styrofoam cups right away, then when they germinate they can grow in the cups until they're well rooted and be planted directly into the ground--skipping the transplanting step! I just put as many seeds as I want for "one plant" in each cup and then put them in a large (shallow) "Rubbermaid type" storage container to put them outside over winter. I like doing things the Lazy Way!

    One other comment about these threads is that, besides perennials, HighAlt also started out sowing "tender" things like tomatoes and annuals, but at some point she decided that it was more effective to start things like that indoors at the appropriate time--when winter sown they didn't come up until late anyway since they need warm temps, so she wasn't "gaining" anything by getting the seeds in soil sooner--and possibly she was "losing" growing season since the outside temps had to warm up enough for them to germinate as opposed to having the warm temps inside whenever she wanted to start them! Just a heads up since I don't know for sure that her comments about changing her mind about winter sowing the warm season crops is in one of these threads!

    There are lots of suggestions in these threads, so you should find something to try, and, eventually, whatever works the best for you!

    Boy, for those of you that have been around RMG for a long time, does looking at these threads ever bring back memories of when the forum was so active and there was so much participation!


  • smdmt

    Thanks for the good links!

  • popmama

    I got pretty enthusiastic a couple years ago and tried winter sowing. Primarily I was hoping for Siberian iris seeds that I had collected as well as Lupines. The iris were a complete no show. The lupines did well but died upon transplant to the larger garden. At that point I decided I was just no good at winter sowing. Those links sure do make one want to try again though. :-)

  • gjmancini

    I havent winter sown in many years, were still not fully unpacked, and Im starting with new seeds this year, cant find my old ones, but.....I loved winter sowing so much, saves on space in the house and lets mother nature do its job.

  • gardenchloe

    Is it too late to winter sow in late January?

  • Skybird - z5, Denver, Colorado

    Not too late at all in my opinion! I thought about potting up a couple cups of seeds a couple weeks ago, but with as warm as it's been around here so far this winter I was afraid they'd all germinate in a week and then we'd get a month-long HARD freeze spell and they'd all be toast--so to speak! There are a couple things I'd like to do, but the weather continues--warm!

    If you decide to do it now I recommend you find "the coldest place you have" to put them to be sure they aren't getting "too" warm during the day. The nites are definitely cold enough, it's our high altitude sun that could seriously mess with them during the day! I'm still hoping it starts to look like we might get a cold spell for a few consecutive weeks--not that I like cold!--but it sure would make "winter" sowing easier! Since there really are at least a couple things I want, if it stays warm for a couple more weeks I think I will find "the coldest" place I can around my house and give it a try. Guess if it starts getting WAY warm on some days I could always stick a corrugated box or something over them to keep the heat off of them, but for somebody who has a lot that would be kind of hard to do!

    If you have seeds that don't really need cold stratification, it doesn't make much difference when you do it!

    Have fun playing,


  • gjmancini

    Im going to put out two milk jugs, i havent decided what seeds yet, but i used to go crazy with it, so i have to control myself....

  • Laura G. Young

    gjmanchi -- Best of luck with the self control! One can never plant out enough seeds..... ;)

    I checked the old threads Skybird posted, and much to my surprise I found my own comments (as Laura_42) from NINE YEARS ago!! Hahaha.

    Yeah, winter sowing is great. I've planted as late as March and had great success with many plants. The only downside is you really need to make sure they're firmly positioned so the wind doesn't blow the containers away and/or keep a sharp eye out for over-heating during those weird warm spells we tend to get some winters.* However I've been getting more and more into native plants/bulbs/perennials, so I haven't been winter sowing as much as I did initially.

    *Side note: I have a gut feeling we could get a BIG snow event this spring. Always seems to correspond with an overly warm/dry spell in January. Newcomers can get taken by surprise, especially if they've been in Colorado a few seasons and think they know what to expect.

    Above pic taken from our Fort Collins home. That's an 8 foot fence.

  • bella rosa

    You might want to read the books by Lauren Ogden Springer. She lives in Fort Collins, CO. I think she also has a home in TX. Her book, "The Undaunted Garden" is my favorite.

  • gjmancini

    So much for the self control, I already surpassed my two milk jugs, Im on number six. I want to get rid of some old seed, so i will give them a whirl with Wsing.

  • Skybird - z5, Denver, Colorado

    LOL! That's the problem with winter sowing, Gloria! I think all of us who have done it have been inflicted with the Don't Know When to Stop Disease! Just remember that in a couple months you'll need to find someplace to plant all the ones that germinate! At least compared to the weather we've been having for most of this winter, the weather tonite sure will make it seem like WINTER sowing!

    Have fun playing,


  • kitasei

    I recoiled at Skybird's suggestion to use styrofoam cups, but then wondered if you use it for insulation?? To avoid the potential for frying seedlings on the warm days, I keep my pots out of direct sun. I think starting siberian iris from seed would challenge anyone. Why bother, when dividing is so much easier? I too have been frustrated by failure with lupines. They're supposed to be so easy! In Scotland I saw fields of them by the roadside! Why why why are they so tricky?

  • ginnytrcka

    Read the book Miss Rumphius and just throw your lupine seeds where you want them to grow. Works for me here in Black Forest anyways.

    I miss gardening and reading this site. I was on here a lot when we first moved to Colorado and especially the other gardenweb forums while we built our house. Gardening went by the wayside as I homeschooled three boys and volunteered for 4H with them as they raised dairy goats and poultry. My husband just retired and now I am dreaming of days in the garden again on this snowy day. Hope I can make the spring swap.

  • Campanula UK Z8

    Lupine will not tolerate lime...I don't think Miss Rumphius's advice is remotely helpful as it fails to address the underlying needs of the plant and actually makes one feel an even bigger failure when even this apparently simple method is a bust. Russell hybrids are a hopeless bet in a calcareous garden - although some hybrids are more forgiving than others - whites and yellows for example. Don't beat yourself up for failure. Like all plants, when soil and climate is right, they will thrive...but unless we want to fuss, amend and faff about with futile attempts to change the ph (always much, much harder to change an alkaline soil to acid than the other way round), best stick with plants appropriate for soil conditions.

    I find the sort of 'just sow and forget' kind of general advice to be one of the most annoying things that some garden writers like to propose - along with something of an idealised view of horticulture which can verge on outright dishonesty - any decent gardener will have a rather long murder list since experimentation is at the heart of all gardening, given the numerous variables at play. Plants are not magic - luck is never involved - like all living things, certain conditions need to be met in order to thrive. These are not mysterious or even very difficult but a little bit of time spent checking on often ignored aspects such as soil ph, daylight length and the many, many online germination sites will have infinitely better results than some vague generalisation which is not specific to YOUR own soil and climate.

  • kitasei

    Here here! Thank you Camp! Now tell me this.. I believe I started my precious sneeze full of lupine seed from Swallowtail in flats or cells inside. Is typical media not acidic enough for lupine? In which case I may have been better off using the Rumpfius method since my own soil is highly acidic.

  • Campanula UK Z8

    Ah, Kitasei - high acidity is also very problematic for legumes (inhibits root formation and affects the growing of nitrogen-fixing nodules)...a ph of around 6.5 is ideal so if you are used to growing bearberries, and rhodies, you might well have done exactly the right thing in avoiding direct sowing. I have the opposite problem of having highly calcareous soil (chalk, shelly sand) so lupines may well survive a single season but will not seed around and never return.

  • NHBabs z4b-5a NH

    My lupines do selfsow in my acidic garden, but I am not trying to grow Russell hybrids. Mine are from hand me down seeds from 30+ years and 3 homes ago. When moving I just gather seeds and plant where I want them since I am helpless at sowing in pots. Otherwise, I just let them fall where they want to and some have always grown. I realize that this may not be helpful to you, but IME fresh seed that plants itself in early summer sprouts and grows enough over the remainder of the season so that it will bloom the following year.

  • hibiscusfan -Northwest Ohio

    Is it to late to winter sow in zone 6?

  • Maribeth

    It is never too late but some things need a cold period to sprout. Folks from your area may have specific advice for you. The FAQ for winter sowing is https://www.gardenweb.com/discussions/winter-sowing-faq. 

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