Here is a picture of Lobelia excelsa. Unless the foliage is highly variable than one of these plants is different. The foliage on this one is not hairy and the leaves are darker green and more linear.

Thanks for that tip. I have lots of the blue ones, they sure are pretty this time of year, plus there must be 40 or 50 seedlings hanging around in the flower beds, hopefully I will get some white ones, I really like them. I wonder if the white ones would come true from seed. Have you tried it and if it does then perhaps I will take you up on your offer for some seeds next spring. Thanks. Valerie

I haven't grown swamp sunflower, but I wonder if it would enjoy the dry heat of SoCal. There are some dry climate sunflowers that might be better adapted to hot SoCal (Encelia californica, Helianthus maximiliani, to name a few). Are you referring to growing these by a real pond, possibly with varying water levels, or a plastic/liner/hardscape pond marginal area? I've grown Joe Pye in full sun without any special cultural care. A gopher seemed to be crazy for the plant--eating the root of one, then tunneling 45' past a variety of other garden offerings, to gnaw on the roots a second plant. I don't know if that was typical behavior, or just that individual's taste bud's delight! They seemed to be short-lived plants in my garden--2-3 years tops--but several seedlings would come up to replace the parents, so it wasn't a problem. The newer, shorter cultivars didn't reseed for me when I grew them I haven't grown that particular lobelia that I recall, but it is Sunset zone rated 4-9. 14-24, so it should do fine in San Diego. Sunset recommends a sunny, wind-sheltered position in fertile, well-drained soil. Regular irrigation.

Im in SW UK coastal site Z10 have been growing Lobelia gibberoa for 4 years (Seeds were from Neslebrae Exotics in NZ) The plants till recently were about 10 feet tall, had lost all lower leaves and gone very leggy, at this stage they were accidently burnt to the ground, but are now regenerating and hopefully will be better shaped plants. Some leaf burn had resulted from offshore salt laden winds, generally tho the plants were easy to grow, are attractive and look a little like Munchia woolastoni I believe their ultimate height is about 19 feet If you put Giant lobelias into your Google search engine you will bring up plenty of websites mainly for hiking and climbing holidays but also with lots of data on the giant plants rencountered on the mountain slopes On the slopes of African mountains such as Kilmanjaro, Kenya and the mountains of the Moon in Ethiopia many different types of Giant Lobelias and Sennicoes have developed, however trying to locate a source of seeds has been impossible - does anyone know a source ? would appreciate help, Ive been looking for years, Thanks Frank in St Ives in SW UK