I live in Apache Junction, AZ and my Lord Lieutenant Anemones this year produced a seed pod and bore seeds. Can I plant these seeds and, if so, how should I do it?
Yes, you can plant the seeds but most people have better luck with dividing the tubers instead. Seed plants will also take longer to mature and bloom. The seeds can be sown in shallow beds with well-draining soil during fall or early spring.
For anemone growing instructions, this article will help: https://www.gardeningknowhow.com/ornamental/bulbs/anemone/anemone-windflower.htm
When do you plant Anemone blanda bulbs? I thought it was in the spring. Not sure since most bulbs are planted in fall.
They can be planted in spring.
The anemone are up and blooming. Do I cut off the dead blooms and stems? Or will this make the plant go dormant? Also, how long do I wait to cut away foliage from tulips, daffodils and alliums?
I wait tell foliage is dying and they will pull right off.
I planted some Honorine Jobert, fall-blooming anemones in the spring of 2011 and nothing has happened. Do I need to wait a full year to see growth?
They should have started to grow by now. Something may have happened to the plant, perhaps rodent damage or rot. Dig gently in the place where you planted them and see if the root system is soft and mushy or firm and pliant. If it is soft and mushy, than root rot got them. If you can't find them, then it is likely rodent damage.
Although Snowdrop Anemone is a pretty and reliable early spring flower in my Zone 4 garden, it spreads prolifically. My question is, if I let it spread, will it crowd out or kill other plants? I know that the balloon flowers that I planted next to it survived only two years before disappearing.
No, it shouldn't crowd out the other plants. While it is a prolific spreader, this plant is not known to be overly invasive.
My Anemone Japonica 'September Charm' is invading my cottage garden. Normally, I use a garden fork to dig out the roots each year, but is there a root barrier solution? How can I find it?
I would recommend digging up as much as you can, then applying either Round-up or boiling water to the area where it was, to kill off any of the remaining roots. Be aware that both Round-up and boiling water will kill whatever plant growth it touches.
You could also implement edging, installing it at least 2-4 inches in the ground to try to keep the roots in bound.
I have three anemone plants, and I do like them, but they are taking over and invading other plant areas and also sending lots of shoots up in my lawn. I need to take these out or find a way to keep them from spreading. Any advice?
Anemones can be aggressive to the point of almost being a nuisance. "But, they are SO pretty." Yes, they are beautiful. Since most grow from rhizomes and tubers, they will be difficult to control. You can try to dig or pull them out, and this might work for a while. This article might help: https://www.gardeningknowhow.com/ornamental/bulbs/anemone/anemone-windflower.htm