I think you are going to have difficulty satisfying all of your requirements. First, unless it's an annual, growing anything from seed tends to be a bit of a long term project - it just takes time for the plant to develop and mature to its ultimate size. Perennials will often take 2-3 years, trees and shrubs significantly longer. And you are going to be looking a lot harder for perennials that will achieve that size AND provide a year round privacy screen. If you do opt for a seed grown annual, look for giant purple millet. It grows rapidly to 5-6 feet, has a dramatic deep burgundy foliage and produces dense seedheads the birds will love. But it does die during winter. I read your first post and understand the restrictions you face. However, you will get much better results and much faster if you can plant started plants rather than seeds. Is there an agency in your area that offers help to disabled homeowners? That may be the way to go. If so, you could plant pampas grass (Cortaderia selloana), an evergreen and very tall ornamental grass that requires very minimal attention once established. It can be planted from seed but you will be looking at several (3-5) years before it provides any kind of significant screening. And there is also the risk of substantial "crop failure" if you direct sow in the garden. Otherwise I'd consider some sort of upright evergreen shrub for your purpose - junipers, yews, etc. I'd also not be overly concerned about your dogs and poisonous plants. Most plants have some toxicity to varying degrees, even some very common fruits and vegetables, but well-fed pets are seldom interested in grazing on them and in most cases they'd have to ingest quite a lot to produce any kind of reaction. Accidental poisonings of dogs and cats consuming outdoor toxic plants are really very rare.

I brought in a batch of 300 moso seeds last year. I have detailed my expermentation with germination on my website trying various recommended techniques, including a table with the variables. You may find it a good read. Check previous entries to read the entire experiment. http://www.hardyoutdoorexotics.com/?cat=11 To make things easier for you, I germinated them directly in soil. I had a 75% germination rate by soaking the seeds in a 10% saltwater solution for 10 minutes, and rinsing off with water before sowing. 67% germination rate with a batch that had an overnight soak in a 20-20-20 solution. And 67% germination rate with a batch that had a soak in a 10-52-10 solution. Those two 67% germination rates were ranked in the top 3 for breaking through the soil the quickest at 21 days. A water soak also broke through at 21 days but only netted me a 58% germination rate. For those that recommend a brief refridgeration for these seeds, germination was delayed, and the success wasn't that great. Here is a link that might be useful: My exotic plants blog

It really took off this summer after repotting, growing 25+ culms and still growing even as temperatures continue to drop. They're up to 4 mm thick and I repotted it in a ~3 trade gallon pot. Would that survive outdoors or should I bring it inside? I also have an unheated greenhouse but it gets moist and moldy inside.

Sporobolus wrightii also called Giant Sacaton. You can buy seeds from Plants of the Southwest. Its a large grass that needs the space of a shrub. The plumes come early & look fantastic backlit. Its very drought hardy. It will take about 3 years to get good sized plants from seed however. Bamboo is extremely invasive. I would never plant the running kind, your neighbors will end up hating you. Unless you are prepared to dig a suitably strong & deep barrier all around it, don't plant it.