While most annual seeds are planted in the spring, many native seeds need to be planted outside in the late fall. They need what is called cold-stratification to break the seeds out of their dormancy. While this can be done artificially, it’s easiest for the home gardener to just do it in an outside garden.
Here’s a technique that I use with good results. I would normally suggest planting the seeds around Thanksgiving. If it is still warm, wait until things cool down.
- Scrape off the top half inch of soil and mulch. You want to get down to the soil level. Set that material off to the side – we won’t use it. If you have weeds in the area, dig them out and put them in your compost.
- You then want to define your seed area so it will be easy to identify in the spring. You can use anything you want – hula hoop, wood, bricks, etc.
- I used a product called Terrace Board which is usually used as a lawn/garden edging. I cut it into twenty foot lengths and then drilled a hole into both ends and used a bolt to connect the overlapping ends. You will probably also need to buy plastic pegs to keep the board in place.
- Another option if you have lots of weeds and/or grass is to lay a couple layers of newspaper to smother the old growth and fill the area with good potting soil.
- I usually also add a half inch layer of compost or potting soil over the soil. We have clay soil in my location and it is not the ideal germinating medium.
- Put in your seeds, cover with another 1/4 inch of potting soil/compost and then water.
- Label the area so you know what seeds you planted.
- The plants you see are Asclepias incarnata – Swamp Milkweed.
- The advantage of this method is that you know that the plants coming up are the ones which are on the label.
I have some milkweed seeds that I’d be glad to share. The seeds are Tropical Milkweed, Asclepias curassavica. Plant the seed so it is slightly covered and keep warm and moist to start. If you start these inside, you can get a a head start on spring. Plant when all danger of frost is gone – usually around May 1st in St. Louis Missouri.
Another option is to plant these in the soil and let them come up naturally.
Send a SASE – Self-Addressed Stamped Envelope to:
Free Milkweed Seeds
9016 Robyn Rd
St. Louis, MO 63126
The best way to start these seeds is with bottom heat.
80 degrees and seeds slightly covered seems to be the best. I did put the plastic top on this to keep in the heat and moisture.
Here’s the procedure I use.
I just found a deal on milkweed seeds that I thought I’d share. I just bought 113,000 asclepias curassavica seeds for just $17.59.
I got them from MyDirtyGardener.com. The link will take you to this offer.
Note – the main Monarch migration is going through St. Louis right now, so get outside and enjoy this phenomenon.
Filed under Milkweed, Seeds
Gateway Greening has seed packets of flowers and vegetables for sale for only 25 cents per package. The main reason they are so cheap is that they are last years seeds. Some may even be older, so they probably won’t germinate as well as fresh seeds.
I’ve been told they are only for sale on Saturdays from 9 a.m. to noon, but since no one is there to take your money, you may be able to get seeds most of the day. You put your money in a box in the seeds area. It’s run on the honor system.
They keep the seeds in the “Carriage House” which is just up the street from the Gardens and they are on the second floor.
As of today, March 5th, they still have a good selection.
Note – this is only a St. Louis thing, you may be able to find another group like this in your city.
I tried the three month cold stratification in the refrigerator for a number of seeds. I use 2/3 peat moss and 1/3 fine sand and then made sure it was moist. After 3 months I took it out of the refrigerator and then made the mistake of leaving it on one of my tables for a couple of weeks. As you can see below, the seeds were ready to sprout. My “Lesson Learned” is that as soon as you pull your seeds out of the refrigerator, put them in a pot so they can sprout.
Here’s my technique for removing the seeds from an Echinacea purpurea, Purple Coneflower. Note – now is the time to start planting these seeds. They do need cold-stratification. I’m using the method recommended by Shaw Nature Reserve.
Caveat : I ended up with a blister on one finger with this method. I’d recommend wearing a bandaid on your index finger or a glove on your hand. I’m going to buy pliers with a Spring-Loaded Hinge, to get around this problem. You can also work the pliers without the spring, you just need to let the handle fall open.
If you haven’t already, now is the time to start saving seeds and then start their period of cold-stratification. Shaw Nature Reserve has a nice PDF on this process and how each species is slightly different.
I’ve already done a detailed report on the process that you can find here.
I’m going to test their three month refrigeration process against leaving seed outside in pots and see how Mother Nature compares.