There is a lot to love about the plumosa fern. Not only is the appearance of this plant unique (and downright funky!), it’s also a tough, adaptable, and surprisingly easy-to-grow plant. In this article, I’ll share my best growing tips for the plumosa fern and offer you all the plant care information you’ll need for success.
What is a plumosa fern?
When I was a professional floral designer, I worked with this plant on a regular basis. It is commonly used as a filler green in floral arrangements because of its soft leaves. Known botanically as Asparagus plumosus (means “plumed”) or Asparagus setaceus (setaceus means “hairy”), this plant is in the Asparagaceae family. It is in the same genus as edible asparagus, but it is a different species. Unfortunately, unlike the asparagus spears you grow in your garden (Asparagus officinalis), the plumosa fern is not edible. Another closely related plant that is popular with gardeners is the springeri fern (Asparagus densiflorus).
Plumosa fern is a perennial vine in hot, tropical climates (USDA Zones 9-12). Where winters are warm, the vine is evergreen and lush year-round. In colder climates, plumosa fern is grown as an indoor plant, though some gardeners put the pot outdoors for the summer. Other common names for this plant include climbing asparagus fern, common asparagus fern, or lace fern.
A native of southern Africa, the climbing asparagus fern can be invasive if it escapes cultivation in warm climates, as it has done in Australia. Plant it with caution if you live in tropical region where it can easily spread.
Plumosa fern traits
Surprisingly, the plumosa fern is not a fern at all. Instead, it is a cousin to edible asparagus. The tiny, wiry leaf-like structures are produced in clumps along the stem. They create soft, feathery foliage that is plume-like. The stems scramble, climb, and cascade unless they are pruned. They can grow 10 to 20 feet long!
Multiple green stems emerge from the base of the plant, each of which develops into a soft frond with time. As the stems age, they develop small, sharp, nearly invisible spines. Be careful when handling the stems if you plan to use them for cut flower arrangements. If you are just growing your plumosa fern as a houseplant, there’s no need to worry about these spines. They are tiny and unnoticeable unless you handle the stems.
Because of the drooping growth habit of this plant, it is perfectly at home in a hanging basket or a pot on a plant stand. With time, the plant will grow quite large and lovely.
The best temperature and light for a plumosa fern
Remember, plumosa ferns are from a tropical climate, so ideal temperatures for this plant range from 70 to 90°F during the day and night-time. Climbing asparagus ferns are intolerant of frosts and freezes, so if you move the pot outdoors in the summertime and put it in partial shade, be sure to move it back inside when cold temperatures threaten.
Indoors, plumosa ferns prefer bright, indirect light. Avoid hot, direct light. South- or west-facing windows are perfect for this plant. Just keep it a few feet away from the window, in a spot that avoids direct sunlight.
When grown as a house plant, this fern-like plant tolerates a wide range of temperatures and does not require high humidity to thrive. Even in winter, when warm forced air from your furnace results in lower humidity levels, this plant will do just fine (unlike some other, far fussier houseplants).
Caring for a climbing asparagus fern
When potting a plumosa fern, choose a slightly acidic, well drained, peat moss-based potting mix for the job. Most sterile potting mixes meant for houseplants will do just fine. They contain both organic matter and a starter fertilizer.
The best kind of pot to use is either plastic or glazed ceramic. Plain clay or terra cotta pots dry out too quickly. Make sure the pot has at least one drainage hole in the bottom.
There is no need to mist plumosa ferns or use a humidity tray or pebble tray underneath the pot. Remember, these plants don’t need high humidity.
Without pruning, the plumosa fern’s tendrils grow long and become quite graceful. But, if the plant grows too large for its location or becomes very overgrown, pruning of the shoots may be necessary.
You have a few options for how to prune the fern-like foliage. First, you can prune it back very hard by cutting some or all of the stems all the way back to the soil. This will stimulate fresh, new growth. However, it will take a good bit of time for the stems to grow back, so only do this if absolutely necessary.
The second option is to pinch back or prune out only the stem tips once or twice a year. This promotes dense foliage growth if you don’t want the plant to tumble and trail over the edge of the pot.
If your plumosa fern becomes gangly and overgrown, you can also prune the long fronds back by a few inches or even a few feet. The plant isn’t too particular and will just produce a new growing point from the nearest growth node and will carry on as usual.
Watering Asparagus plumosus
Plumosa ferns need consistent moisture. They should not be left to dry out completely. That being said, never leave the roots sit in water for longer than an hour or two or root rot could result. Instructions for watering plumosa ferns are to take the pot to the sink and run cool water from the tap into the top of the pot. Let it flush through the soil and drain out the holes in the bottom of the pot. Run the water for a minute or two before letting the pot fully drain. Then put it back on display. Depending on the temperature and humidity of your house, along with the plant’s location, watering may need to occur every 5 to 10 days.
In the winter, water the plants only sparingly and far less often. While plumosa ferns don’t require a winter dormancy, they are not actively growing through the winter months and therefore require much less water. Keep the soil on the drier side during the winter, then resume more frequent waterings when spring arrives.
To fertilize a plumosa fern, use a standard houseplant fertilizer that is either a liquid fertilizer, a spike, or a granular formation. I find it easiest to add fertilizer to my irrigation water every four weeks or so, but you might find plugging a fertilizer spike into the soil once a year or sprinkling a granular fertilizer on top of the soil every 6 weeks far more convenient. The plant won’t care where its nutrients come from, as long as the right kind of fertilizer is used.
Only fertilize plumosa ferns (and other houseplants for that matter) when they are actively growing. Do not fertilize in winter. Here’s more information on how to fertilize houseplants.
Repotting and dividing a climbing asparagus fern
Eventually climbing asparagus ferns produce large, stocky root-like tubers that can crowd the pot. When this happens, you’ll find yourself needing to water more often. The roots will also begin pressing against the side of the pot and can cause it to become misshapen. That’s a sure sign that the plant needs to be repotted or divided and propagated.
If you are dividing the plant, remove it from the container, perform a root division by slicing the root ball in half with a sharp knife, and repot a chunk of the plant using fresh, sterile potting soil as described in an earlier section. This is a type of vegetative propagation. You can pot up the other divisions in the same manner to share the plant with friends.
If you don’t want to divide the plant but would prefer to pot it up into a larger container, choose a pot that is 1-3 inches larger than the previous pot in diameter. Loosen the roots before replanting the plant into the new pot using fresh, sterile potting soil.
Plumosa fern problems
These lovely houseplants are fairly care-free. However, occasionally there can be issues. The green, needle-like leaves often drop from the plant, and when they do, it is no cause for concern. However, if you have yellow leaves that drop, it is often a sign of insufficient light. Move the plant to a brighter location. Too much sunlight can cause the leaves and buds to bleach and become a pale green.
There are a few common pests that affect this plant, primarily when it is put outdoors during the summer months. Mealy bugs, spider mites, aphids, and scale can sometimes hitch a ride indoors when the plant is moved back inside in the autumn. If you find any of these insects to be problematic, a lightweight horticultural oil or insecticidal soap should do the trick.
Do Plumosa ferns flower?
Surprisingly, plumosa ferns do produce tiny, bell-shaped, white flowers on the stem from time to time. Remember, this plant is not a true fern. True ferns are not capable of producing flowers (they reproduce by spore, not by seed), but plumosa ferns do flower. The blooms are followed by green berries that ripen to dark purple. They are reportedly toxic if eaten (diarrhea and abdominal pain is the result), so consider carefully removing them before they mature if this concerns you.
As you can see, the plumosa fern is a lovely, adaptable addition to your houseplant collection. Because of its trailing growth habit, established plants look extra beautiful when displayed on an elevated plant stand or shelf where they can tumble down over the side. When given the proper conditions and care, this foliage plant can live for decades.
For more on growing unique houseplants, please visit the following articles:
- Caring for the blue star fern
- Venus fly trap basics
- Pilea peperomioides care
- Growing air plants
- The string of dolphins plant
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