Ornamental artillery plant, Pilea microphylla, aka gunpowder or pistol plant, military fern, or rockweed, is an herbaceous perennial.
It is one of about 600 types of non-stinging Pilea species in the Urticaceae, or nettle family.
This tropical species thrives outdoors year-round in Zones 11 to 12 as a short-lived evergreen perennial. It is also grown as an outdoor annual or indoor houseplant in all zones.
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In this article, we’ll discuss all you need to know to grow and care for your own artillery plant indoors.
It has a creeping growth habit and may reach mature dimensions of six to 18 inches high and 12 to 24 inches wide.
The artillery species has plump leaves like a succulent. They are either green or variegated pink and white, one-eighth to one-half inch long, and “obovate,” or rounded and narrower at the base. The leaves are arranged in opposing pairs, like a fern frond.
In nature, the species produces tiny pinkish flowers followed by brown fruits. And while flowering is unlikely to occur indoors, it’s fun to know about it because the names “artillery,” “gunpowder,” “military,” and “pistol” come from an unusual characteristic.
There are both male and female flowers, and the males literally propel pollen into the air, as in an aerial attack.
Historically speaking, the artillery species has undergone numerous botanical reclassifications by Swedish botanist Carl Linnaeus and later botanists, including Parietaria microphylla (1759), Pilea muscosa (1821), P. microphylla (1851), and P. trianthemoides var. microphylla (1869).
These synonyms and “basionyms,” or name equivalents and their predecessors, still pop up in plant searches, so it’s good to be familiar with them.
The artillery species is native to the Caribbean, Mexico, Central and South America, and the southeastern United States.
In its native habitat, it is a somewhat weedy, spreading ground cover that commonly sprouts between rocks and in lawns, in margins between land and water, and in masonry crevices.
The species has been introduced around the world, and is classified as invasive or at high risk for becoming invasive in many places because it readily naturalizes via stolons, or runner roots, as well as self-sown seed.
Today’s cultivated varieties are robust versions of the hardscrabble wild species. And while indoor cultivation does not pose a threat to the landscape, we do not recommend letting P. microphylla spend the summer outdoors in temperate zones as we do with many houseplants, in order to avoid inadvertently introducing it to the landscape.
This tropical species thrives best with a daytime temperature range of 65 to 85°F and 1000 to 2000 foot-candles of daylight, which is another way of saying bright indirect light.
Lower light is well-tolerated but usually causes shading to dark green, so don’t waste money on a variegated variety if you choose a dim location for your plant.
And growth may be more horizontal than upright. A little pruning of leggy stems contributes to a more compact form.
If you have a very dim setting, such as a windowless office, that you wish to add a plant to, you’ll need a grow light.
To grow your own P. microphylla, you’ll need to start from seed, take a stem cutting from an existing plant, divide an existing plant, or purchase a nursery start.
Outdoors, this is a vigorous self-sower that disperses tiny seeds with gusto, contributing to its invasive tendencies.
However, starting from seed may pose a challenge, as most retailers sell live plants and seeds can be hard to come by.
With their unique, almost alien-looking foliage, it’s no wonder artillery plants are becoming increasingly popular houseplants Once you acquire one of these beauties, it’s only natural to want more! Propagating your own artillery plants is a great way to get new plants for free However, there are some key things to know about propagating these quirky specimens correctly.
In this comprehensive guide, we’ll walk through the Artillery Plant Propagation Process 101 so you can increase your plant collection the right way Let’s get growing!
Why Propagate Artillery Plants?
Propagating gives you several advantages over buying new plants
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It’s free! Save money by getting more plants for no cost.
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You can replicate your prettiest, healthiest parent plant instead of starting from scratch.
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It’s faster than growing artillery plants from seed.
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You can trade or gift plants to fellow plant-lovers.
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It’s rewarding and fun to watch new baby plants form.
When’s the Best Time to Propagate?
Spring is prime propagation season for artillery plants. The increasing daylight and warm temperatures of springtime spur root growth and give new plants the ideal conditions to flourish.
You can technically propagate year-round but may see slower progress in winter or summer. Early fall can also work well as plants prep for dormancy.
Step 1 – Select a Healthy Parent Plant
Pick a mature, thriving artillery plant as your propagation source. Avoid sickly, stressed, or overwatered plants, as their cuttings likely won’t root well. Select young, vigorous growth rather than old stems.
Variegated varieties with pink or white coloration tend to propagate the best. The variegation is easy to preserve when propagating.
Step 2 – Sterilize Your Tools
Before making any cuts, thoroughly clean and sterilize the pruning shears/scissors you’ll use with isopropyl alcohol. This prevents spreading diseases between plants via your tools.
Also wipe down the area you’ll be working on. Sanitation is key!
Step 3 – Take Cuttings
Using your sterilized shears, take 3-6 inch tip cuttings from your artillery plant. Cut just below a node where leaves emerge. Make a clean 45 degree angle slice.
Stripping the lower leaves from cuttings allows for better root formation. But leave several leaves at the top for photosynthesis.
Step 4 – Dip in Rooting Hormone (Optional)
For the best rooting results, dip the bottom 1-2 inches of each cutting in a powdered rooting hormone. Rooting hormone contains compounds that encourage root growth and development.
While not 100% necessary, rooting hormone does boost your propagation success rate significantly. It’s worth the small investment.
Step 5 – Plant in Soil or Water
You have two options for where to place your cuttings to root – directly in potting mix or suspended in water. Let’s look at both methods:
Soil Propagation
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Fill starter pots with well-draining potting mix. Perlite-amended soil works well.
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Poke holes and insert cuttings at least 1-2 inches deep. Gently firm soil around them.
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Keep soil consistently moist but not sopping wet. Reduce water once roots form.
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Partial sun is ideal. Avoid hot direct light while newly rooting.
Water Propagation
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Place cuttings in jars/vases of clean water, deep enough to submerge the node areas.
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Change water every 4-5 days to prevent bacteria growth. Distilled/filtered water prevents rot.
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Suspend in bright, indirect light and avoid direct sun exposure.
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Once roots reach 1-2 inches long, transfer to soil.
Step 6 – Be Patient!
Rooting and new growth will happen gradually, so armed yourself with patience. Most cuttings will show roots in 3-8 weeks.
Maintain warmth and high humidity while they root. Resist the urge to disturb them too much.
Step 7 – Transition to Soil
For water-rooted plants, wait until the root system is well-developed before moving to soil. Gently tip plants from water and lower into pots, supporting soil around the roots.
Keep freshly potted plants sheltered for 1-2 weeks while they adapt. Then begin acclimating them to normal conditions.
Troubleshooting Propagation Problems
If your artillery plant cuttings fail to thrive, a few issues could be to blame:
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Declining parent plant health
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Using old, woody stems
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Letting cuttings dry out
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Excessive direct light exposure
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Temperature fluctuations
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Bacterial rot from unclean tools
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Potting mix staying too wet
Adjust your care and environment to get propagation back on track! With some trial and error, you’ll get the propagation formula right for successfully multiplying your artillery plant collection.
Enjoy Your New Artillery Plant Babies!
From selecting top-notch mother plants to troubleshooting propagation problems, you now have an A to Z guide to properly propagating artillery plants.
Follow these tips and with a little time and TLC, you’ll start Spotting tiny new leaves emerging on your cuttings. Celebrate when those first delicate little roots appear! Before you know it, you’ll have a whole artillery plant army thriving.
From a Stem Cutting
If you know someone with a plant already, you can get a head start by taking a cutting.
To propagate a stem cutting, make your cut about four inches from the tip of a growing stem at any time during the spring or summer.
Use clean shears and choose a spot to cut that’s just below a leaf node. This is a natural growing point, where roots will readily sprout.
Pinch off the lower leaves to reveal a bare stem about two inches long.
Place the bare stem in one inch of water in a narrow container that can support it, like an old unused drinking glass. There should be no leaves below the water line, as they will start to decay and foul the water.
Place the glass in a location with bright indirect sunlight, such as near a window with an opaque curtain. Avoid direct sunlight, as it may burn the foliage and roots with its intensity.
Change the water daily.
When roots sprout over the next couple of weeks, you’ll have a cutting that’s ready to pot up, which we’ll discuss shortly.
In addition to calling upon another gardener to assist you with the cutting method to get started with your first plant, you may be lucky enough to have a friend who is getting ready to repot. In this case, you can ask for a division.
This method involves unpotting and dividing one plant into two or more sections and transplanting the sections to their own containers.
You can learn how to divide an herbaceous perennial in our guide.
If you haven’t got a repotting friend, it’s time to get your wallet out.
Managing Pests and Disease
With indoor cultivation, you are not likely to face many issues. Some common houseplant pests prefer very dry environments, while fungi and bacteria favor dampness.
Try to keep the indoor humidity at or above 45 percent, and avoid both under- and overwatering as well as direct sunlight.
Even with the best care, pests may appear. You may encounter:
Some are more likely to prey upon flora grown outdoors, but you should be aware of the possibilities.
If a stream of running tap water doesn’t dislodge the offending insects, try one or more of the following:
Treat sapsuckers and caterpillars with an application of organic neem oil.
Apply food-grade diatomaceous earth to the soil. It addresses sapsuckers as well as flying pests and gastropods, and remains in the potting medium as a preventative measure against future infestation.
Place yellow sticky tape products formulated specifically for trapping flying pests near affected pots.
In the event of an extensive infestation, you may have to remove severely damaged foliage by cutting stems just above a leaf node or at the base.
As for diseases, the following are known to afflict P. microphylla:
- Anthracnose (Colletotrichum spp.)
- Myrothecium Leaf Spot (Myrothecium roridum)
- Pythium Root Rot (Pythium spp.)
- Rhizoctonia Aerial Blight (Rhizoctonia solani)
- Southern Blight (Sclerotium rolfsii)
- Xanthomonas Leaf Spot (Xanthomonas campestris)
As we said, indoor specimens are less likely to suffer from these ailments than plants grown outdoors.
However, if yours should become infected, there are both chemical and biological treatments for fungal and bacterial conditions that you can try.
If the damage is extensive, it is often better to discard the plant and sanitize the pot with a 10-percent bleach to water solution (one part bleach to nine parts water).
Pilea Microphylla Artillery plant propagation care & tips.
FAQ
How to propagate an Artillery Plant?
Where do you cut polka dot plants for propagation?
How often should I water an artillery fern?