Can I save my perennial seeds from coneflowers, coreopsis and milkweed, or do I need to plant them now?
Yes and no. These three perennials have different requirements regarding when to plant seeds. Some can be planted before winter; one needs to be saved until spring. Coreopsis should be planted in the spring and can also be started inside, 6-8 weeks before the average last day of frost for your area, or direct sowed outside after the danger of frost is passed.
Coneflower seeds require cold and moist stratification to break dormancy and can be directly winter sown in January or February. They can also be sown outside in the spring but will require 30-60 days of cold and moist stratification in the refrigerator before planting.
Milkweed can be direct sown on bare soil in October or November, as these seeds require a prolonged cold and moist stratification,
with freezing and thawing, to break dormancy. Milkweed seeds can also be planted in the spring but will require at least 30-60 days of cold and moist stratification in the refrigerator. Extra seeds not planted can be stored in the freezer and will remain viable for several years.
Another factor to consider is whether your plants are native or a cultivar, which may be a hybrid. Cultivars which could be hybrids may not produce the exact flowers as the parent plant.
Is this a good time to transplant bearded iris?
The ideal time to transplant bearded iris is mid- to late summer, July through August, approximately 4 to 6 weeks after they have finished blooming. This time frame will allow the rhizomes to develop a good root system before the ground freezes. October, especially this late in the month, is a bit late, however given the mild winters we have had, could be worth the risk. I would plant them immediately, mulch around them when and if the ground freezes, removing the mulch in the spring. One year, further north in Missouri, I had some iris in the garage in December that I had meant to plant but didn’t. We had an impending snowstorm, so I threw them at the edge of the garden and threw a bunch of straw over them, no digging at all. They not only survived the winter, but bloomed the second year, forming a very large cluster of iris.
What is a good way to prevent weeds from growing in my garden over the winter?
The best way to prevent weeds over winter is to manually remove as many weeds as possible before winter and keep the soil covered throughout the winter to kill any existing weeds and to prevent weed seeds from germinating. The soil can be covered with 2-4 inches of shredded leaves, straw, or wood chips. Some utilize a cover crop such as winter wheat, rye, clover, or oats, which are tilled under in spring. Cardboard or newspaper covered with mulch will also smother weeds.
Readers can pose questions or get more information by calling 417-874-2963 and talking to one of the trained volunteers staffing the Master Gardener Hotline at the University of Missouri Extension Center in Greene County located inside the Botanical Center, 2400 S. Scenic Ave., Springfield, MO 65807.
This article originally appeared on Springfield News-Leader: When to plant coneflower and milkweed seeds and other gardening tips
