Tips for an Easy to Grow Tuberous Sundew (Drosera indumenta)

Winter-growing, tuberous sundews are becoming much more popular to grow since propagated material is becoming more common and folks are getting over the intimidation of trying these beautiful but sometimes challenging plants.  Drosera hookeri (once called D. peltata until Robert Gibson revised this group)  is one of the first I usually recommend since it is easy and reliable, and even produces seed through self-pollination.  

Another tuberous sundew that is equally as simple to grow is D.indumenta.  We have been growing and selling seed-grown plants of this species as D. aff. macrantha 'swamp form'.  Recently, however, we have come to realize that Allan Lowrie, in his huge three volume magnum opus on carnivorous plants of Australia, released last year,  has re-named this plant as the species D. indumenta,  part of the macrantha complex.  Two major differences are that D. macrantha has white flowers, while D. indumenta has pink flowers and is also covered entirely with tiny hairy glands along the climbing, wiry stems and even the petioles of the leaves.

I've grown D. indumenta for many decades, but for a long time had only one plant.  I then grew a second plant from seed; it took a few years for it to flower, which gave me the chance to finally cross-pollinate them and get viable seed (nearly all tuberous sundews need to have their flowers cross-pollinated with another genetic clone).

In The Revised SavageGarden, released in 2013, I have an introduction to the habits and cultivation of tuberous sundews on pages 192 -195.  There I mention that if you are able to get an established, potted tuberous sundew, consider yourself lucky!  This is because growing them from seed can take a few years to reach maturity, and receiving Australian-cultivated tubers gives you the challenge of having to adjust the plants to our reversed seasons of the northern hemisphere.  On page 195 there is the photo of this plant and description, but it is listed as Drosera macrantha ssp. macrantha, which it was known as at the time.  If you have purchased D. macrantha from California Carnivores in the past, please change the tag's name to D. indumenta.  At the nursery we also grow the true D. macrantha, and it has white flowers as identified in Lowrie's magnum opus.  (His three volumes are so enormous, when I made the mistake of lifting them all at once, I got a hernia!  Only kidding!)

Our potted D. indumenta are currently in full growth and rather beautiful.  They can be grown in greenhouses that are cool in winter, often on sunny south-facing windowsills, cool tanks under grow-lights, or even outdoors if you live in a cool winter climate that doesn't get much frost.  This species easily takes minimum temperatures into the 30s F, but our greenhouse has a minimum winter temperature of 50 F and during the day can be in the 70s and even 80s in the afternoon with no problems.

 

We begin wetting the soil in late September and keep the pots wet, sitting in pure water, from late October through spring.  The plants usually emerge from the soil in November/December and grow until about April.  When they turn brown and go dormant, we then dry out the pots slowly.  We still sprinkle them about every couple of weeks during the summer dormancy so as not to desiccate the dormant tuber.  It might be dangerous if the soil gets so dry it shrinks from the edges of the pot.  They make a nice substitution for dormant plants you might grow in a tank under grow-lights, such as removing a Venus flytrap in Autumn for it's dormancy, and replacing it with a winter growing plant such as this.

Be mindful that D. indumenta can get large, but the wiry stems are very flexible.  They usually reach maximum size of three feet in length, but we've had them also reach seven feet on occasion!  There is one right now in our greenhouse that is climbing up the polycarbonate wall, straight up, cementing its longer leaves to the plastic.  If you look closely at climbing sundews, like D. indumenta, you will notice short leaves and long leaves. The short leaves are only for catching prey, while the long leaves are capable of permanently cementing themselves to any physical object. If support is not provided, they will simply climb, droop and scramble over other pots and plants.  When mature, the plants will terminate with large, pink, fragrant flowers, a nice bonus to an already wonderful species.