Q: What is this invasive grass? I am unable to find a seedhead. Ken Pruitt, email

A: It is tough to identify grassy plants by characteristics other than a seedhead. You have to observe the grass’s awns, ligules, auricles, and collars. Those plant parts are beyond most gardeners' ability to identify. The only way I am reasonably confident at grass identification is when I see the seedhead. If you want to learn the specifics of grass identification, see bit.ly/GAgrassid.

Q: My neighbors and I want to plant some type of tree or large shrub that will take root and survive on an island on Lake Nottely. The island is Georgia clay and is submerged four months out of the year. It receives full sun. Jim Clark, Blairsville

A: Offhand, only willow and bald cypress could fit the bill. I don’t know if it’s accurate, but one online article says young cypress trees can’t be flooded for more than 45 days. On the other hand, researchers in Canada reported that pussy willow, Salix discolor, and sandbar willow, Salix lutea, could survive long periods underwater.

Q: For 45 years I have grown at my homes near San Francisco the original St. Augustine grass my grandfather brought from Louisiana. I nurtured them to full lush carpets in both places. Would it be successful to get some of that grass and grow it here? T. Fuqua, Stockbridge

A: My own lawn grew from St. Augustine grass sprigs I collected from an older home in Candler Park. My theory was that if the St Augustine grass had survived there for 50 years, it was cold hardy enough for my home in Decatur. There is much variation in the cold tolerance of different varieties of St. Augustine grass. It is certainly worth a try to plant the grass from California, but don’t put a lot of effort into it until it’s been through a couple of Atlanta winters.

Q: Should I plant Spanish or English bluebells in the woods behind my house this fall? Which will do better in my area? Sally Ganey, Newnan

A: I think they both will do fine. I have had Spanish bluebells, Hyacinthoides hispanica, at my Decatur home for 30 years. English bluebells, Hyacinthoides non-scripta, have violet-blue flowers and a pleasant scent. My Spanish bluebells have pale blue flowers and no scent. Gardeners in England prize their native bluebells, and if you confuse the two, they will be very cross with you.

Listen to Walter Reeves' segments at 6:35 AM on “Green and Growing with Ashley Frasca” Saturday mornings on 95.5 WSB. Visit his website, www.walterreeves.com, follow him on Twitter @walterreeves, on Pinterest, or join his Facebook Fan Page at bit.ly/georgiagardener for more garden tips.