What are appropriate cover crops for this fall in Juneau (Mendenhall Peninsula/Fritz Cove road area)??. and is there a Best to plant them?
Planting a cover crop (aka green manure) in the fall is a great idea and will take hold with no problem in the Fritz Cove area of Juneau. It is highly recommended to mix legumes and non-legumes because of their different contributions to the soil (legumes fix nitrogen while fast growing non-legumes capture nutrients, preserve soil, etc.).
Look for a "fall cover crop mix" containing legumes (field peas, hairy vetch, and/or red clover) and non-legumes (oats, annual ryegrass, and/or buckwheat) which you can find at most of your favorite seed supply companies.
You can plant a cover crop at any point during the Juneau mid and late summer. Planting by early August will ensure you have a good stand before it's growth is ceased by the onset of winter.
Note: PLEASE take care not to introduce known invasive plants by referring to this guide and if your interested, also take a look at this excellent app. A quick cross check will ensure your successful care for our native Alaskan landscape.