Sowing Milkweed seeds in Winter - using the Milk or Water Jug Method:
By Mike the Bee Guy
Supplies needed for Winter Sowing using a 1 Gal. Plastic Jug:
Plastic 1 gallon Clean Milk/Distilled Water Jug.
Seedling Soil ONLY, (NOT Potting Soil).
A little bit of sand, (I buy a bag of “Play Sand”, it’s fine & light).
A Nail 1/8” - 3/16” diameter, 3” to 5” long or a cheap pointed soldiering iron (to make drain-holes on bottom of jug).
Sharpie
Razor Blade or Scissors to cut around 3 sides of jug.
Spray bottle with water.
Paper towel to dry outside of jug.
Duck Tape.
How to:
Use the nail, or the heated soldiering iron to put the drain holes in. Pierce the bottom of the jug with 12 - 16 holes.
Place the jug, standing up on a flat surface, with the handle pointing at you & towards your right side.
Using the sharpie, draw a line 3-1/2 inches (9cm) up from the bottom of the jug, starting on the left side, going around the far-side and along the right side. You will end up with a line on 3 sides of the jug, when you cut along this line, you will end up with the top of the jug being able to flip open, with the 4th, uncut side acting as a hinge.
Put some dry seedling soil into a bucket or container. Slowly pour water in while mixing the soil. You want the soil to be completely moist, so when you grab a handful & squeeze it, a little water drips out & the soil stays in a clump. It’s better to have a bit too much water in the soil, than not enough. (Extra water will drain out).
Fill the Jug with soil to the cut line, then gently press or tap the soil down, I use a wooden block, ( this will insure all air pockets are forced out so the roots will always be in contact with the soil). Now put more soil in, tap it down, continue until soil level is about 1/4” (6mm), below lip of Jug.
DO NOT “plant” YOUR SEEDS IN THE SOIL. Sprinkle your 🌱Milkweed seeds lightly on TOP of the soil, do not let seeds overlap each other, seeds should have a little space between them.
“Set” your seeds into the soil, gently press them down, so the bottom of the seed is in 100% contact with the soil, be careful, they may sick to your finger.
Very Lightly sprinkle some dry sand, thinly & completely covering the seedling soil & seeds.
Use the spray bottle to completely wet the sand.
Dry the outside (the bottom isn’t necessary) of the jug.
Flip the top half of the jug down, line the halves together.
Use the duck tape to completely go around the jug twice, sealing the 2 pieces together.
Use the sharpie to write the seed variety on at least 2 sides of the jug.
Remove & throw-away, (I mean recycle), the cap to the jug.
Place the jug along the North side of your house, (so it doesn’t get ANY direct sun).
Leave it alone until Spring. The winter rains should supply all the water it needs. If you peak down into the jug & notice the sand is completely dry, use your spray bottle to gently soak the sand.
The Last Frost of the season in Campbell is Feb 17. Find your own Last Frost Date, just type in your city: https://www.almanac.com/gardening/frostdates/CA/Campbell,%20Santa%20Clara%20County Mark this day & a week before this day on your calendar.
A week before your Last Frost Date, move your jugs to the South side of your house or where they will get direct sunlight, the seeds will sprout within 30 or so days, depending on the weather, spray water into the jug as necessary so it doesn’t dry out. No more than every 3-5 days.
Check the jug once a week or so, when the majority of your seeds have sprouted & have their 2 “True Leaves”, (a total of 4 leaves), you can now remove the tape & transplant the seedlings into separate cups or pots.
Transplanting the seedlings.
Prepare the Potting Soil. I always sift (using a 1/2” or 1/4” screen) the dry potting soil 1st, then put into a bucket and slowly pour water in while mixing the soil. You want the soil to be moist completely thru. If you squeeze the soil into a ball in your hand, it should drip water a little bit & keep it’s shape. Fill the cups or containers to the top with the potting soil.
Since the seedlings are so young, the roots are mainly a tap root, have a bucket of warm water handy & either 16 oz. Solo Cups with drainage holes drilled in or 4” tall garden containers, filled with sifted potting soil, Do NOT tap down or compress the potting soil. All containers MUST have Drain Holes.
With a butter knife, I gently cut out a block of the seedlings & soil, remove them from the jug and gently swish them around in the water bucket to remove all the seedling soil. Now you can gently untangle the seedling roots WITHOUT damaging the roots.
Use your finger or a chopstick to create a hole in the center of the transplant cups or pots soil, about as deep as the roots are long.
Take 1 seedling & place it in the hole as deep (or a little deeper) as the seedling was in the jug. Then press the soil from the outside of cup/pot towards the seedling, making sure the soil is completely touching the roots. Fill the rest of the cup/pot with potting soil, gently press the soil. The soil level should be 1/4” to a 1/2” from the top.
Use a small garden watering can until water drains out the bottom. You shouldn’t have to water again for at least 5 days. Too much water is the #1 reason for milkweed seedling loss.
After about 3 - 4 weeks they are ready to be given away or transplanted into native Californian soil (rocky, sandy, even clay).
Water every 5 - 7 days, make sure soil almost drys out in-between watering. Slowly cut back on water, if you see the plant drooping due to not enough water, (mostly on a very hot day), water it & note how long its been since last watering. Use that as a guide to watering. The next Spring the milkweed should come back & not need any extra watering from you.
In the 2nd year you should get flowers & seeds. Tie your seed pods closed with rubber bands when you see the seed pods turning color from green to yellow to prevent the pods from drying, cracking open & having your seeds disbursed by the wind. Please save at least 80% of your seeds for future planting, friends & neighbors, don’t forget about me😁, the more seeds you give me, the more starter plants our group can give-away in Spring. I would gladly accept as many seeds as you can give me.