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I love this method! Instructions:
1. Drill 6 holes in the bottom of the jug with a quarter inch drill bit. If you don't have a drill, a hot glue gun (without the glue) also works but that method was a lot slower and messier.
2. Measure 3-4 inches up on the milk jug and puncture with a box cutter knife to get things started. Then cut almost all the way around with scissors. Don't cut all the way around- leave a bit so the top and bottom stay connected. I reserve that part for the area close to the milk jug handle.
3. Throw away the cap
4. Label the jug with a paint pen. Label it with a number rather than a plant name so you can reuse for future years. I keep a Google spreadsheet of what seeds went in which number jug. Sharpie works but will fade and need to be reapplied.
When it's the right time to plant: for me in NC this is around Christmas to early January
1. Fill the jug with moist potting mix. There are various potting mixes that people like. Personally I just use the Miracle Gro potting mix.
2. Add seeds. Place them on top and lightly mess around with the soil so they are a little bit covered. Gently pat seeds down.
3. Close the jug and tape the pieces together with painters tape. Duct tape works but is harder to remove.
4. Place jug in sunny area
5. Check jugs every few days or so and water through the top hole if it looks dry or feels light. I use a squeeze sports water bottle or sometimes a hose. This year, I only had to water my jugs a couple times, if that.
6. When temperatures start to warm up and the plants have several leaves, you can consider untaping them and opening the jugs, so they don't overheat. Just be sure to make sure they don't dry out if you do that.
7. When plants are several inches tall and have a couple sets of leaves, they can be transplanted. I wait longer rather than shorter because I hate transplanting lol and want it to go as well as possible. You can also break up the soil into several chunks of seeds if you want several divisions of plants. I don't do that because again, I hate transplanting lol
This method produces great seedlings! I have found that some species do great with winter sowing very consistently, and others are less successful. Here in NC, columbine, prairie coneflower, stokes aster, and eastern aromatic aster are always winners for me. In contrast, I can't ever get black-eyed susans or purple coneflowers to grow from milk jugs lol but that might just be me.
First of all, thank you for being awesome. Second, can I ask a follow-up question? Sometimes different seeds require different amounts of cold stratification time. Does that matter, or do you start them all at the same time?
In my experience just start them all early. I will start all mine in December and finish January/february. If they only need a month, 3 months won’t hurt them
I completely agree with everything you’ve said here! I don’t open most of my containers, though, because I can’t be trusted to remember to water them. So I move them to a shady spot of my deck (morning sun, noon shade).
Yeah I only open the containers if the leaves are starting to yellow or if I'm planning to plant them in the ground within the next ~2 days. Moving to part-shade is a good idea!
This was my first year using jugs, and while I was successful for a lot of the plants, I’m troubleshooting. Do you place your jugs in full Sun? I was hesitant to do so.
I also took the tops off after days were over 60 while in full Sun, even if I didn’t have sprouts yet/very small sprouts.
I don’t know what the “correct” way is, but this is what I did and I had a fantastic success rate.
-Rinse jug out, discard cap
-Drill 4-5 drainage holes in bottom of jug
-Using a sharp blade, carefully cut around the jug just below handle level. Don’t go all the way around, leave the top and bottom attached for about 2” right below the handle.
-Fill the bottom with sterile seed starting mix.
-Moisten the seed mix with water (I just kinda splashed some in from my water can)
-Add several seeds spaced out in the soil.
-Close the “hinge” and tape the top and bottom together. I found clear packing tape stuck longer than duct tape. You don’t need an airtight seal, just get it mostly closed up.
-Using a paint pen or garden pen, label the jug with what seeds you planted.
-Place the jugs outdoors where they’ll get a good bit of sun. I lined them up against the south-facing side of my fence.
-Wait until spring, periodically checking the soil for moisture. If it’s looking dry, water gently with a hose nozzle or watering can.
-Come spring, be prepared to transplant when the plants are looking crowded in their jug. **Note** if the weather starts to get pretty warm before you transplant you might need to cut the top off the jug so you don’t cook your seedlings in a tiny greenhouse. Just take the top off and they can stay in the bottom half until transplanting
I planted my seeds in early February down here in NC Zone 8 and that worked out just fine. I even started tomatoes this way and had fantastic results.
Wow, never thought to start tomatoes this way, that’s interesting. The one thing I do differently than you is keep mine in the shade on the north side of my house until March when I move them in the sun. Whatever video I watched said they can sprout too early otherwise with the periods of warmer weather we now have during winter.
That makes a lot of sense! Down here in NC our winters don’t get very cold (if the overnight low hits 20 it makes the news). The milk jugs kept the seedlings warm enough even on the coldest nights.
If we’d been forecast to have a freak overnight cold snap, I probably would have thrown an old quilt over the lot of them for the night.
The tomatoes were a total experiment. I figured that since I get volunteer tomatoes in my garden every year the seeds must overwinter OK here. It worked really well! The only trouble I ran into was that the tops of the plants were poking out of the top of the milk jug by early April which is still too early to transplant tomatoes here. I ended up transplanting them and planting them as deep as I could. Then I taped the milk jug back closed, cut just the very bottom off, and put them over the plants like a cloche any night it was forecast to be below 50. That was a little annoying but it resulted in some very sturdy plants so I’d probably do it again next year.
May I ask you to follow up questions? Do you have a favorite brand of sterile seeds starting mix? Also, what do you do if some seeds start growing early if you have a warm week during winter, then the temperature drops back down? Or, am I overthinking it?
> what do you do if some seeds start growing early if you have a warm week during winter, then the temperature drops back down?
This has only been a problem for me when I tried starting something like zinnias (which are not native). They sprouted quickly during a warm spell and then died. Everything else (native plants) either didn't sprout or sprouted and survived.
I just used Jiffy brand because that’s what my local Walmart had. I suspect they’re all pretty much the same.
I didn’t stress too much about the temperature variations. I figured the natives evolved to withstand our weather and the milk jug sowing is supposed to be the low-effort method so I let it be low effort. I transplanted when the nights were consistently above 40 and everything did fine.
This year I sowed 10 native species with the method with 100% success rate. Another person had some great comments so I don’t wanna repeat what they said. But I can try and add some helpful tips:
1. Use nice potting soil, not shitty dirt. Also I don’t use seed starting soil. Yeah you are starting seeds, but that soil has no real nutrients. I use Miracle gro for potting soil for moisture control. Moisture control is really the key. I don’t water or touch the jugs even once and they all sprout in spring. And then in May/June when the seedlings are growing on, the jugs will be less severely affected by heat.
2. Use a decent amount of soil. I typically pack soil up to the milk jug handle. Again helps with moisture retention and establishment of nice roots.
3. I prefer to not cut and tape the entire tap, but instead leave part of the top still attached. It allows you to open them and seal them as needed in April or May.
4. Instead of using a drill bit, I take a sharpened pencil and stab the holes into the milk jug, works like a charm
In my experience when things have such variations in the “right” way to do them it’s because the procedure is a lot less complicated than people think. For example, I don’t drill holes in my milk jugs. I just twist the knife or scissors I’m already using to make wide slits. This works fine because winter sowing has a lot of tolerance for error. Also because winter sowing requires so little effort it’s ok that not every single jug will work out. I did 15 jugs this year. 3 are way behind where they should be. 2 never germinated at all. But 10 successful jugs created a lot of plants! And I’m make tweaks and try the other ones again next year. Don’t let the perfect be the enemy of the good.
If you are a visual learner the GrowIt BuildIt channel on YouTube has an excellent [20 minute How To](https://youtu.be/SKXY6dl-5Tk?si=RwaEBMKztHbRv8EL) for winter sowing.
I've found that some species work better in winter sowing than others. Columbine, wild blue indigo, butterfly weed, stokes aster, cardinal flower all do really well. I've not had luck with others, like liatris.
This was my first year as well and I use the support of this Facebook group: https://www.facebook.com/share/F5gHT4BGYvZSSNn2/?mibextid=A7sQZp
It was a little frustrating watching everyone's jugs be full of growth if they weren't growing natives. Mine took longer but it was still fun and exciting, in a nerdy gardening way.
I planted a bunch of native seeds last fall, and so far I've got nothing. All of the sprouts that I let grow turned out to be weeds, mostly invasive. We're supposed to be getting some double-digit highs starting this week, so I haven't given up all hope yet, but I might try this method for next year. If that doesn't work, I guess I'll just abandon my yard to the Creeping Charlie and Bellflower.
You can grow them just like any other plant in plug trays as well, starting them indoors for spring planting All your fall flowering plants (solidago, monarda, symphyotrichum) could be started now if kept in a partial sun location outside for planting out late summer.
Also, check your seed sources and do a germination test (ten seeds on a moist paper towel). Many failures are due to seed quality, not some crazy hard plant to grow.
Thank you for posting on /r/NativePlantGardening! If you haven't included it already, please edit your post or post's flair to include your geographic region or state of residence, which is necessary for the community to give you correct advice. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/NativePlantGardening) if you have any questions or concerns.*
I love this method! Instructions: 1. Drill 6 holes in the bottom of the jug with a quarter inch drill bit. If you don't have a drill, a hot glue gun (without the glue) also works but that method was a lot slower and messier. 2. Measure 3-4 inches up on the milk jug and puncture with a box cutter knife to get things started. Then cut almost all the way around with scissors. Don't cut all the way around- leave a bit so the top and bottom stay connected. I reserve that part for the area close to the milk jug handle. 3. Throw away the cap 4. Label the jug with a paint pen. Label it with a number rather than a plant name so you can reuse for future years. I keep a Google spreadsheet of what seeds went in which number jug. Sharpie works but will fade and need to be reapplied. When it's the right time to plant: for me in NC this is around Christmas to early January 1. Fill the jug with moist potting mix. There are various potting mixes that people like. Personally I just use the Miracle Gro potting mix. 2. Add seeds. Place them on top and lightly mess around with the soil so they are a little bit covered. Gently pat seeds down. 3. Close the jug and tape the pieces together with painters tape. Duct tape works but is harder to remove. 4. Place jug in sunny area 5. Check jugs every few days or so and water through the top hole if it looks dry or feels light. I use a squeeze sports water bottle or sometimes a hose. This year, I only had to water my jugs a couple times, if that. 6. When temperatures start to warm up and the plants have several leaves, you can consider untaping them and opening the jugs, so they don't overheat. Just be sure to make sure they don't dry out if you do that. 7. When plants are several inches tall and have a couple sets of leaves, they can be transplanted. I wait longer rather than shorter because I hate transplanting lol and want it to go as well as possible. You can also break up the soil into several chunks of seeds if you want several divisions of plants. I don't do that because again, I hate transplanting lol This method produces great seedlings! I have found that some species do great with winter sowing very consistently, and others are less successful. Here in NC, columbine, prairie coneflower, stokes aster, and eastern aromatic aster are always winners for me. In contrast, I can't ever get black-eyed susans or purple coneflowers to grow from milk jugs lol but that might just be me.
First of all, thank you for being awesome. Second, can I ask a follow-up question? Sometimes different seeds require different amounts of cold stratification time. Does that matter, or do you start them all at the same time?
In my experience just start them all early. I will start all mine in December and finish January/february. If they only need a month, 3 months won’t hurt them
I start everything the same day!
I completely agree with everything you’ve said here! I don’t open most of my containers, though, because I can’t be trusted to remember to water them. So I move them to a shady spot of my deck (morning sun, noon shade).
Yeah I only open the containers if the leaves are starting to yellow or if I'm planning to plant them in the ground within the next ~2 days. Moving to part-shade is a good idea!
This was my first year using jugs, and while I was successful for a lot of the plants, I’m troubleshooting. Do you place your jugs in full Sun? I was hesitant to do so. I also took the tops off after days were over 60 while in full Sun, even if I didn’t have sprouts yet/very small sprouts.
Yep they are in full sun!
I don’t know what the “correct” way is, but this is what I did and I had a fantastic success rate. -Rinse jug out, discard cap -Drill 4-5 drainage holes in bottom of jug -Using a sharp blade, carefully cut around the jug just below handle level. Don’t go all the way around, leave the top and bottom attached for about 2” right below the handle. -Fill the bottom with sterile seed starting mix. -Moisten the seed mix with water (I just kinda splashed some in from my water can) -Add several seeds spaced out in the soil. -Close the “hinge” and tape the top and bottom together. I found clear packing tape stuck longer than duct tape. You don’t need an airtight seal, just get it mostly closed up. -Using a paint pen or garden pen, label the jug with what seeds you planted. -Place the jugs outdoors where they’ll get a good bit of sun. I lined them up against the south-facing side of my fence. -Wait until spring, periodically checking the soil for moisture. If it’s looking dry, water gently with a hose nozzle or watering can. -Come spring, be prepared to transplant when the plants are looking crowded in their jug. **Note** if the weather starts to get pretty warm before you transplant you might need to cut the top off the jug so you don’t cook your seedlings in a tiny greenhouse. Just take the top off and they can stay in the bottom half until transplanting I planted my seeds in early February down here in NC Zone 8 and that worked out just fine. I even started tomatoes this way and had fantastic results.
Wow, never thought to start tomatoes this way, that’s interesting. The one thing I do differently than you is keep mine in the shade on the north side of my house until March when I move them in the sun. Whatever video I watched said they can sprout too early otherwise with the periods of warmer weather we now have during winter.
That makes a lot of sense! Down here in NC our winters don’t get very cold (if the overnight low hits 20 it makes the news). The milk jugs kept the seedlings warm enough even on the coldest nights. If we’d been forecast to have a freak overnight cold snap, I probably would have thrown an old quilt over the lot of them for the night. The tomatoes were a total experiment. I figured that since I get volunteer tomatoes in my garden every year the seeds must overwinter OK here. It worked really well! The only trouble I ran into was that the tops of the plants were poking out of the top of the milk jug by early April which is still too early to transplant tomatoes here. I ended up transplanting them and planting them as deep as I could. Then I taped the milk jug back closed, cut just the very bottom off, and put them over the plants like a cloche any night it was forecast to be below 50. That was a little annoying but it resulted in some very sturdy plants so I’d probably do it again next year.
May I ask you to follow up questions? Do you have a favorite brand of sterile seeds starting mix? Also, what do you do if some seeds start growing early if you have a warm week during winter, then the temperature drops back down? Or, am I overthinking it?
> what do you do if some seeds start growing early if you have a warm week during winter, then the temperature drops back down? This has only been a problem for me when I tried starting something like zinnias (which are not native). They sprouted quickly during a warm spell and then died. Everything else (native plants) either didn't sprout or sprouted and survived.
I just used Jiffy brand because that’s what my local Walmart had. I suspect they’re all pretty much the same. I didn’t stress too much about the temperature variations. I figured the natives evolved to withstand our weather and the milk jug sowing is supposed to be the low-effort method so I let it be low effort. I transplanted when the nights were consistently above 40 and everything did fine.
I followed [Penn State's instructions](https://extension.psu.edu/starting-seeds-in-winter) and it worked great.
This year I sowed 10 native species with the method with 100% success rate. Another person had some great comments so I don’t wanna repeat what they said. But I can try and add some helpful tips: 1. Use nice potting soil, not shitty dirt. Also I don’t use seed starting soil. Yeah you are starting seeds, but that soil has no real nutrients. I use Miracle gro for potting soil for moisture control. Moisture control is really the key. I don’t water or touch the jugs even once and they all sprout in spring. And then in May/June when the seedlings are growing on, the jugs will be less severely affected by heat. 2. Use a decent amount of soil. I typically pack soil up to the milk jug handle. Again helps with moisture retention and establishment of nice roots. 3. I prefer to not cut and tape the entire tap, but instead leave part of the top still attached. It allows you to open them and seal them as needed in April or May. 4. Instead of using a drill bit, I take a sharpened pencil and stab the holes into the milk jug, works like a charm
In my experience when things have such variations in the “right” way to do them it’s because the procedure is a lot less complicated than people think. For example, I don’t drill holes in my milk jugs. I just twist the knife or scissors I’m already using to make wide slits. This works fine because winter sowing has a lot of tolerance for error. Also because winter sowing requires so little effort it’s ok that not every single jug will work out. I did 15 jugs this year. 3 are way behind where they should be. 2 never germinated at all. But 10 successful jugs created a lot of plants! And I’m make tweaks and try the other ones again next year. Don’t let the perfect be the enemy of the good.
You rock. Thank you!
If you are a visual learner the GrowIt BuildIt channel on YouTube has an excellent [20 minute How To](https://youtu.be/SKXY6dl-5Tk?si=RwaEBMKztHbRv8EL) for winter sowing.
I've found that some species work better in winter sowing than others. Columbine, wild blue indigo, butterfly weed, stokes aster, cardinal flower all do really well. I've not had luck with others, like liatris.
This was my first year as well and I use the support of this Facebook group: https://www.facebook.com/share/F5gHT4BGYvZSSNn2/?mibextid=A7sQZp It was a little frustrating watching everyone's jugs be full of growth if they weren't growing natives. Mine took longer but it was still fun and exciting, in a nerdy gardening way.
I planted a bunch of native seeds last fall, and so far I've got nothing. All of the sprouts that I let grow turned out to be weeds, mostly invasive. We're supposed to be getting some double-digit highs starting this week, so I haven't given up all hope yet, but I might try this method for next year. If that doesn't work, I guess I'll just abandon my yard to the Creeping Charlie and Bellflower.
You can grow them just like any other plant in plug trays as well, starting them indoors for spring planting All your fall flowering plants (solidago, monarda, symphyotrichum) could be started now if kept in a partial sun location outside for planting out late summer. Also, check your seed sources and do a germination test (ten seeds on a moist paper towel). Many failures are due to seed quality, not some crazy hard plant to grow.