Posted by: John Stolzle, Jefferson County Extension
We’re
well
into autumn, tilting further into the dormant season..
but this doesn’t have to be a time completely devoid of plant life,
of green, of fresh produce and herbs. You can
have
freshly
fallen foliage
on your floor 365
days a year, if
you like. Personally I enjoy the weirdness that comes with being surrounded by green plants while it is snowing outside, but that's just me.
But while
we’re at it, why not consider raising a
world of green insectivores that live on the brink? Carnivorous
plants
that
consume
other organisms on a regular basis. It
sounds
very much the
stuff of sci-fi
and imagination. In
reality, quite a variety of these curiously adapted organisms exist
in nature. And
as
fearsome and tough as they may seem or
sound from reputation,
carnivorous
plants can be quite sensitive. They
need care and particular
environments to thrive.
 |
In this blog post, I outline a little information on some of the more common carnivorous plants which you may be more likely to encounter in a garden nursery. At the end of the post I have also included links to information on less ‘fussy’ and more resilient plants that will just grow and be happy in a wide array of indoor environments, no doting required.
Along the way, I will be providing plenty of links to further reading for a variety of these topics.
Carnivorous
Plants
In this blog post, I outline a little information on some of the more common carnivorous plants which you may be more likely to encounter in a garden nursery. At the end of the post I have also included links to information on less ‘fussy’ and more resilient plants that will just grow and be happy in a wide array of indoor environments, no doting required.
Along the way, I will be providing plenty of links to further reading for a variety of these topics.
In the harsh reality of
Colorado’s climate, many of these plants
would not survive a
week outdoors. It’s
dry, the soil is challenging in many respects, and
the temperature and
weather fluctuates seemingly by the hour; however,
in climate
controlled home environments, these botanic curiosities can have a
place right by any bedside.
But even indoors, they need a little extra care. As a kid, I always wondered why the mighty Venus Flytraps I purchased would die within a week. One problem is that I was treating them like quasi houseplant-animals rather than specialized organisms which needed time to acclimate. I wanted to see them eat bugs, but what they needed was time… and likely for me to stop poking them every 10 minutes.
Carnivorous plants have evolved to flourish in environments which are very low in accessible nutrients (low in Nitrogen and minerals salts, for example). But these plants do not primarily get their sustenance from their living meals; rather, they convert light into sugars (via chloroplasts) like all plants. They capture and 'process' their prey to compensate for their low-nutrient environments – it's like they take supplements in the form of digested insects! It’s a method to obtain a few specific things here and there but not a primary means for the plants to obtain energy. Also, don’t feed them raw meat.
Before diving in, an amazing list of detailed
recommendations for the cultivation of various carnivorous plants may be found
here: https://www.carnivorousplants.
Venus Flytraps (Dionaea muscipula)
 |
| Venus Flytrap - Dionaea muscipula James Henderson, Golden Delight Honey, Bugwood.org |
These little shop of horror-esque curiosities are native to a coastal
region in North and South Carolina. The can consume an array of insects but in the wild their diets primarily revolve around ants,
spiders, and even small beetles; the plant will clamp down when an insect brushes by two of its
internal hairs. Once trapped, insects are digested in about a week (or a little more), after which the jaws reopen in preparation for another meal. If the plant's mechanism is accidentally triggered or an insect manages to escape, it will take about 8hours for a trap to reopen. A mixture of Sphagnum moss and sand is often used as a growth medium for Venus Flytraps. But it is important to note
that they (and many other carnivorous plants) do not grow well in salty
soils; Venus Flytraps and are so sensitive that even using “hard”
mineral-heavy water can have a detrimental impact to their health. Use distilled
water when possible, and try to keep them in an environment above 50%
humidity. Because it is so dry here in Colorado, it might be
necessary to grow one in a terrarium or other semi-sealed type of
environment.
More information on the Venus Fly trap:
- https://www.ndsu.edu/pubweb/
chiwonlee/plsc211/student% 20papers/articles02/dhodgson/ dhodgson.html - https://www.uaex.edu/yard-
garden/resource-library/plant- week/venus-flytrap-2-24-06. aspx
Sundews (Drosera spp.)
 |
Sundew - Drosera spp.Rob Routledge, Sault College, Bugwood.org |
This genus (group of species) of plants ranges drastically in color
from pinks to purples with reds in between; some have long thin
tentacle leaves while others have short stubby spoon shaped leaves.
The hairs on the leaves are tipped with a sticky substance that traps
insects. Upon detecting a trapped insect, the leaf will roll itself
up and begin digesting its meal. The Sundew then absorbs the
nutrients through its leaves. Some research suggests that Sundews can
obtain 20-57% of their required nitrogen from prey. A word of caution, if you
decide to try growing one, do a little research on your variety.
The needs of these plants can vary quite a bit between species of this genus; for example, some cannot handle dried
mealworms as a food source while others can, some can tolerate a
little bit of dryness while others do well in pots placed in trays of
water. More detailed information for cultivating these plants can be found here:
https://www.carnivorousplants.
-
Interesting to note that there do exist some questions for why the genus has such varied coloration, more information on that can be found here:
http://blogs.evergreen.edu/
pim-group1/drosera-capensis/ -
More general information on Sundews here:
https://mlbs.virginia.edu/
organism/drosera_rotundifolia
Pitcher Plants (varied)
This group encompasses multiple genera of similar plants.
 |
Darlingtonia californica - California Pitcher PlantHarlan B. Herbert, Bugwood.org |
The pitcher plant Darlingtonia californica (aka. California Pitcher Plant) is native to Oregon and California. True to their namesake, these plants grow in a pitcher-like form. An insect will find itself drawn into the pitcher, fall into a small pool of water at its base, and then struggle to escape due to various possible plant adaptations (for example, some species have smooth and slick pitcher walls, others have downward pointing hairs or small spines). The water at the base of these plants is often enhanced with digestive enzymes, and nutrients are absorbed through the walls of the plant at the base of the pitcher. The California Pitcher plant has a twist in its pitcher to help retain prey, it is also somewhat unique in that it relies on bacteria and microinvertebrates to help breakdown trapped insects.
 |
| Darlingtonia californica - California Pitcher Plant Harlan B. Herbert, Bugwood.org |
- Additional
reading on the California Pitcherplant:
http://online.sfsu.edu/
bholzman/courses/Fall01% 20projects/pitcherplant.htm
I won't go into detail on the Napenthes pitcher plant (image below), other than to say it is another common variety; more information can be found in the links following the image.
 |
| Nepenthes Pitcher Plant |
|
- https://www.uaex.edu/yard-
garden/resource-library/plant- week/Nepenthes-Pitcher-Plant- 09-16-2016.aspx - https://www.uwb.edu/wetlands/plants/nepenthes-carunculata
- https://jhgreenhouse.biology.
indiana.edu/features/ carnivores/Nepenthes-sp.html
Carnivorous plants can be challenging to grow, but the challenge can be
part of the fun. And one day, all of the pieces may come together and
you might find yourself with a terrarium full of curious wonders. It just
takes some deliberate preparation: a semi-enclosed terrarium, growth
medium (sphagnum moss and sand or other), proper lighting and
watering. Alas, it seems so simple. Fortunately in-depth guides exist
(previously linked). But, if you're like me then you might want some plants that just grow well indoors without a lot of fuss.
If you’re interested in learning more about the kind you can just "give water and they’ll grow", then I highly recommend you check out the following few links:
-
Great selection guide:
https://extension.umd.edu/
hgic/topics/selecting-indoor- plants - More
information plant-by-plant:
https://planttalk.colostate.
edu/topics/houseplants/ - More
information on succulents:
https://planttalk.colostate.
edu/topics/houseplants/1329- succulents/ - Brief
about some benefits of
houseplants:https://cals.
arizona.edu/yavapai/anr/hort/ byg/archive/houseplantsi
mproveindoorairquality2015.html
A short Afterward
These curious carnivores are pretty cool, unfortunately many species are threatened, endangered, and some critically so, due to poaching, habitat destruction, and so forth. There do exist licensed vendors for these plants. And so if you are interested in trying to grow one of these curious terrors, do a little investigation and please make sure you are getting your exotic plants from a reputable source.If you are interested in learning more about indoor gardening, then you might also be interested in checking out these other posts in this indoor blog series:
And as always,
Best of luck in your gardening endeavors!
Perfect timing for this information. Thanks!
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