The latest data from Mexico shows the Monarch population is down 26% from the previous year.
If you’d like to provide support for the Monarchs as they come north, you need to plant as much milkweed as possible. Here are some varieties that I have tried in the past.
Swamp Milkweed – Asclepias incarnata Does best it wet soil, but will grow for three years in typical garden soil. Save the seeds and replant in the fall or start inside after cold stratification. If you have large clumps, you can also separate them as new plants. This is the one milkweed in St. Louis that will come up and be available for egg laying in April.
Butterfly Weed – Asclepias tuberosa Does best in poor dry soil. Like lots of sun.
Tropical Milkweed – Asclepias curassavica Easy to grow annual. I start these seeds around March 15th to have plants ready for Monarchs around April 15th.
Common Milkweed – Asclepias syriaca While this plant is easy to grow in almost any setting, it does wander all over the garden and out into the yard. If you have the space where it can wander then give it a try. I took mine out. I’ve grown it in a large pot for a couple of years, but it died out.
Other Milkweeds I have tried, but without long-term success.
Asclepias-exaltata Poke milkweed
Asclepias hirtella – Tall Green Milkweed
Asclepiad purpurescens – Purple Milkweed – lovely, but doesn’t last.
One of the easiest ways to double your tropical milkweed plants is to take cuttings from the new seedling plants and put them into water. I’ve found that aluminum cans works well. In around two weeks your cuttings will have roots which you can plant into new containers.
Below is what my old plants look like after I cut them down and let them grow back for two weeks.
Since I had a ten day Florida vacation planned, I thought I’d try and germinate my tropical milkweed seeds while I was gone.
The trick is to keep the seeds moist and warm during that time and make sure they don’t dry out. I not only watered the seed bed well, but I also covered it with a plastic well-fitting top. I put the shop lights right above the plastic lid. I then left on vacation and after ten days, this is what I came home to.
I came home to hundreds of seedlings and look forward to transplanting them into other containers.
It’s April 21st and in St. Louis we have just been visited by our first Monarch butterfly. This was a female looking for milkweed to lay eggs on.
What is interesting to note is that just six days ago, we had frost yet the cooler temperatures have not hurt the monarchs or the milkweed.
Unless you have started milkweed from seed, most people won’t have any milkweed to provide the visiting monarchs.
Swamp Milkweed is one of my favorites in spring as it has a lovely form and beautiful flowers.
The problem we have is that it only lasts three or so years before it dies off. The problem is probably the hot dry summers we have, which is not conducive to any plant with swamp in it’s name.
To avoid having to buy new plants every year, make sure you collect the seeds when they ripen on the stem, put them in a paper bag and then plant them in late fall where you want them to grow. Next year you will be rewarded with lots of new plants free of any cost. You can also buy seeds online and plant them outside in the fall.
Another trick I have learned is that your can dig up plants early in the spring and divide them. This way you may end up with six plants instead of one.