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.
