Please note! This and other plants in the series have proven non-invasive in our environment and, based on our experience, are cautiously recommended for trial by water and bog gardeners elsewhere. Having said that however it should be noted that anytime plants are moved to an area in which they are not native there is a risk that they could become invasive. For this reason they should be contained rather than set free in the natural environment and dead heading prior to release of seeds is recommended. It should also be noted that the fact that they perform well in southern Ohio (zone 6) doesn't mean that they will do so in other areas.   

Charles Leach

Just one way water gardeners can help green the planet . . .

Native alternatives to invasive plants
First in the series

Boltonia decurrens
(False Aster)

by Charles Leach, Ohio USA
Click images to enlarge

As part of an evaluation of plants native primarily to the north central United States, we obtained seeds of Boltonia decurrens (false aster), along with other seeds from Prairie Moon Nursery. It specializes in seeds and plants of species native to the north central United States including bog, wetland and pond species.

We tried seeds from another well known source but were disappointed with both the selection and viability. A particularly troublesome practice of said source, along with being stingy with the number of seeds in their high priced packets, was sending pre-moistened seeds that sprouted in transit and died when potted. Prairie Moon on the other hand is extremely generous with the number of seeds in packets that cost just $2.00 each and germination rate is excellent. Based on customer reviews, I guess I’m not their only fan.

Having said that, it should be noted that their great variety of seeds includes those of species that can be highly invasive or toxic. One case is water hemlock, so buyers must research before ordering seeds. To prevent spreading a highly invasive species I suggest that buyers go with varieties listed as threatened by state or federal agencies.

Boltonia decurrens (false aster) is listed as threatened by the federal government and by the states of Illinois and Missouri in which it is native. I planted the seeds in damp seed starting mix in the fall, stretch-wrapped the seed flat and left it outside over winter. Soon after being unwrapped in the spring practically 100% of the seeds germinated.  


Somehow a few cells that didn't get divided and repotted got mulched over and lost until July of the following year and were only found when I was pulling what I thought were weeds in the area. To my surprise I found the roots of the over 3’ (1m) tall plants confined to tiny seed cells labeled false aster, pictured below left. 

Like most wetland plants, false aster transplants well if the soil is kept wet. As evidenced by the lost seed cells, pot size doesn't matter a lot as long as the roots are kept damp. I have had false asters in 6" (15cm) pots reach a height of 6' (182cm) but, to avoid having the plants fall over, I recommend far larger containers.

The plants on each side of the door shown below are growing in 10" x 10" (25 cm x 25 cm) containers without drain holes. The photograph at the left was taken in mid June. By mid July the plants were nearly 6' (182 cm) tall and the first of the flowers that would cover the upper branches for weeks were opening. The second photo shows them in early August when they were over 6' (183cm) tall and covered with flowers, as they will be into September. 

< Mid June, about 5'
(150cm) tall.

Early August, over 6'
(183cm) tall and
covered with flowers >


Although happy in their drain hole free pots they suck up about a gallon (4 liters) of water each a day. For what it's worth they were dug out of a pathway immediately adjacent to a where a false aster was growing in a marginal pool the year before. So far no volunteer false asters have turned up any distance from where they have been growing. The ones that do turn up do not take over an area because they don't spread from rhizomes.   

A word to the wise -- never turn a species that spreads by rhizomes loose in open ground or along the edge of a natural pond. I made the mistake of planting a Solidago graminifolia (grass leaf goldenrod) in a bog garden a couple of years ago. It’s an attractive plant with a bamboo-like appearance but spreads like wildfire in both wet and dry soil. We have been trying to contain it ever since.

Foliage of false aster is attractive from early spring till winter, although the spent flower stems die back and should be cut off, and it covers itself with small daisy-like white flowers in late summer. A false aster on blocks in a 24" (60cm) deep tub kept falling off the blocks whenever the wind kicked up so I eventually decided to let it stay on the bottom to see what would happen. The photo below left shows it happily blooming with over a foot (30cm) of water over the crown. It was still happy with a skim of ice on the water in November, below center, and it showed green leaves peaking through a couple inches of snow in December, below right.  

As it appeared that there were healthy roots on the underwater stems I broke a couple of pieces off, potted them and brought them into our sunroom. One died and the other survived but, now that it is back outside, is less than a foot (30cm) tall. Don't quite understand why it needs a period of cold weather, as it doesn't go totally dormant, but it seems to.

With the return of warm weather I decided to repot the false aster that wintered over at the bottom of the tub. When I removed it I was surprised to find that it was detached from the pot and growing happily hydroponically. The photo at the right shows me holding the free floating plant for a portrait. After the picture was taken the plant was put in a 12" (30cm) deep tub along with a clump of umbrella sedge that is also growing happily in water without soil. Sometime in the future I intend to experiment with using both in an improvised biological filter to remove nutrients from pool water.  


Boltonia decurrens is a great and versatile plant that is well worth trying in any water or bog garden in, at least, northern areas. Having it in your garden will help insure survival of a threatened species. How good is that?   

Read the introduction to this series
Alternatives to Invasive Water and Bog Garden Plants

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