Hey Billy..I had to Google setaceus. It looked exactly like my Plumosis. Dave's Garden and Wikipedia confirmed setaeus and plumosis are one and the same.

Got my setaceus/plumosis in the 90's at our grocery store, sold as an annual/accent plant.
Setaceus grows erect, especially when mature.

Let's see..they love the outdoors. Bright shade when young. As they mature, '2'+', they'll adapt to very bright indirect sun.

My mix consists of AV soil, a little Peat, Perlite, a small amount of All Purpose and extra-small pebbles.

In summer or when a room is warm, soil dries fast..Keep moderately moist.
Too hot or dry and fronds brown. Another reason when outside, shade is safer.
In winter they 'need' misting and/or showering. They prefer medium to high humidity, but medium is sufficient.

Soil should be mildly acidic, 'reason AV soil and Peat's added.

In winter, they prefer a cool to chilly room. They're one of the last plants brought indoors..Last autumn mine came in in November.

That's about it..Every so often a little vinegar, and fertilized once a month with Fish Emulsion, the next month, Acidic.
They're evergreen, but growth slows/stops Nov-Dec. I stop feeding in Sept/Oct then restart in Mar/Apr.

Plumosa is cared for the same as Asparagus, Ming, and Fox Tails.

Billy, they're beautiful plants. Although, they're not true ferns, care is about the same...the only difference is they adapt to less humidity than, say a Boston.

A friend kept her Asparagus and Plumosis in an unobstructed south window, year round. They were drop dead gorgeous. Direct southern sun..Her appartment had high ceilings, Asparagus reached the floor..Beautiful.

Good luck. If you can grow a Boston, you'll definately be able to manage a setaceus. Toni

Hey thanks Toni for all the information!Maybe that's what happened, it never dried out, but maybe the soil wasn't moist enough at some point.
I have a couple of Bostons and they both do very well with low humidity, it's usually not enough water that makes the fronds drop, so if I watch the watering better it should do well.
Your friend had a setaeus that she gave it direct sun and almost reached the floor? Or was that the Asparagus 'Densiflorus 'Springeri' you mean? Either one is really something if you can get them to grow big and hang down to the floor. I can only imagine how beautiful that plant must have looked!

Thanks again:)
Billy Rae

Hey Billy..Water and cool in winter. The two most important things to keep most Asparagues + species alive. And of course sun.. :)

My friend had both A. Springeri and A. setaceus, started from little 4" plants. They were gorgeous..Hanging on beautiful macrmes, 'she made them,' hung before several, 'maybe 6' south windows..Tall ceilings.
She misses them too. 'personal stuff.' Let's say her ex went balistic one day and...............

But she took pictures...'paper, not digital.'

You might like other species, too, Billy. Foxtail and Mings are soooo nice..Toni

Yes, I do like the foxtail, it has a look all it's own. Had A. Springeri which was a very messy leaf dropper ar times, not to mention re-potting it all the time to a larger pot. I missed repotting it just one or two seasons and the big clay pot 10" or more, broke into three or four pieces, dirt everywhere. No thank you on getting that one again!

I didn't think A. setaceus would like a lot sun, but I will give it more then last time I had one. The last one received bright light with very little sun and it did ok, it was the watering I probably messed up on. Maybe I'll try the foxtail if I see one, sometimes Lowe's has a few.

Billy Rae

Billie..sorry I'm responding so late, but been SUPER busy digging the yard, front and sides of our house..Yesterday, we finally bought annuals, one or two perrenials, and veggies. Most are in the ground. I worked outside until 9pm. lol. Minutes before T-Storms hit.

Before placing your A. setaceus in direct sun, do so gradually. My friend, who grew hers in a bright, south, lucked out. My Asparagus, Ming, Foxtail, Asparagus, and Setaceus/Plumosis, are outdoors. They get some direct sun, but partially shaded by a tree.

When they're indoors, they're before south and east windows, plus artificial light, so taking them out where they'll live throughout summer isn't too harsh.

Asparagus Fern fronds brown when room temp is too hot. They'll do great at 40F degrees, but indoors, when heat is on, fronds yellow or brown, then drop. Yes, they are messy. lol.

But the same applies to setaceus. Keep as cool as possible.
When my setaceus was a baby, I potted in a clear, plastic pot, in a red jelly. lol. It looked so pretty..problem is, this jelly//gel evaproates. It lasts about a year.
Since there was extra, when the jelly evaporated, I'd make more..'forgot how it was made.' I think water was added, it turned into a gel. It came in different colors..green, blue, yellow and red. I chose red..Absolutely no nutrients, lol. After I ran out of jelly, my setaceus was potted in soil.

HD had setaceus in 4" pots for 2.39. There alongside Asparagus Ferns, the outside department..they're sold as Accent Plants.

Anyway, just wanted to let you know, before placing your plant in direct light, acclimate. Toni