For today’s post we’re talking plant care + I’ve put together an Asparagus Fern care guide. I’m back in writing mode + am currently working through some reader requests, so I hope you find this post helpful if you have, or have been thinking about getting hold of one of these softly draping, gently sculptural houseplants.
Before we get any further though let’s address the slight naming discrepancy because despite their common name, these plants aren’t actually true ferns, but are part of the Lily family (Lilaceae) instead! The naming is more a nod to their appearance — the plants in this group do share visual similarities with other ferns, particularly some of the more delicate-looking types. In warmer climates Asparagus ferns grow outdoors as garden plants, whereas in cooler conditions like the United Kingdom, they make a slightly more unusual indoor plant. As I always say in my Plant Care posts, thinking about where your plants grow in nature will really help you to understand their care needs. Asparagus ferns hail from South Africa in a shady, subtropical environment. In the wild, these plants are often seen growing as ground cover + spread easily, but as a houseplant, they also grow very well in a planter.
In my experience, I’ve found that they aren’t the most popular of plants + often look quite unassuming in their nursery pot. Saying that though, I first started growing my favourite of the 3 I have about 4 years ago + at the time, was one of the plants I decided to pick up as it was different to the other plants I was growing. I wasn’t entirely sure if it would last long-term, but I’m happy to report that it’s still alive + still in my collection today! The elegant plumes of feathery foliage (called cladodes — short, flattened stems that look/function like leaves) can create a soft display that looks effortlessly cool when hung or allowed to trail down a shelf. Mine really has grown to become an understated staple in my trailing houseplant setup. Please note that these plants are toxic + harmful if eaten, so keep out of reach of children or pets.
In the post, I’ll be going into the topics of:
- humidity + leaf care
- potting mix (+ pots)
- plant display, propagation + pruning
Within the Asparagus fern group, I have 3 varieties + I care for them all the same — I thought I’d include photos of them all for you to see here:
– Asparagus densiflorus Meyeri — also known as Foxtail fern, Myers’ Asparagus, Foxtail Asparagus.
This foxtail fern is a beautiful plant that is chunkier in form than the others + as the plant matures, is can really get big + bushy! Here’s one I spotted at the RBGE:
– Asparagus setaceus — also known as Lace Fern, Asparagus Grass.
The most delicate type of Asparagus Fern I’ve grown, this is a little tricker than the other two, but can look very elegant on a table or desk. They are really popular in bonsai pots (below right) as they have a striking resemblance to a tiny tree! Mature specimens can grow to be stand-out plants + one of my customers has a huge one that she gives a bit of cold black tea to + swears it keeps hers looking luscious!
– Asparagus densiflorus ‘Sprengeri’ — also known as Emerald Fern, Emerald Feather.
This one is my favourite of the three for it’s long growth + resilience to less than perfect conditions, plus it’s the one I’ve featured the most in this blogpost. It’s the least likely to shed too in my experience! Of the three here, this one is my recommendation if you are thinking about picking one up.
Asparagus ferns are pretty adaptable in terms of their lighting requirements + over the years I’ve experimented with growing these plants in a number of homes + conditions. In my previous apartment my Emerald fern really came into it’s own around 1.5-2metres from a South-West facing bay window (I’m in the northern hemisphere for reference). Here it received a few hours of late afternoon sunshine + trailed down the side of my plant shelf (I’ve included an earlier photo of my plant when it was just starting to trail below).
As this was a brighter position there was the occasional yellowing of older foliage, but this also meant that growth was faster + the stems were robust + grew to be long + fluffy over a few years in this position. In brighter positions, you might encounter some shedding, which can be a little messy! But overall, I have found that in a brighter position, the growth is also noticeably more compact + dense than in more ambient settings. In my last place, I placed my plant 1 metre away from a South-East facing window, protected by a net. This created a much softer light + resulted in slower (but still steady) growth. Currently I’m growing this plant in a North-West facing location in front of a large window as I work on the renovation, so I’ll observe over time how this compares.
With these plants, it’s about finding the balance in giving them enough light to grow well, without anything too harsh or intense that will cause the foliage to look washed out, or dried + yellow in colour. In their natural habitat, Asparagus ferns enjoy softer dappled light, so if you can replicate this in an ambient, filtered spot, you’ll be on the right track (they received an honourable mention in my low light tolerant plants blogpost). Remember that this is an adaptable houseplant so give it time to acclimatise gradually if you want to move it — particularly if moving it from a darker position to a brighter one. In very dark positions though, the plant will yellow if it’s not receiving adequate light so if you want to keep your plant full + bushy, be sure to rotate regularly to achieve a balanced growth habit. I found that when my plant was on a shelf against a wall, the back of my plant would yellow + shed if I didn’t move it. That’s why it works particularly well as a hanging planter which gets soft light all around (though this isn’t always possible to achieve of course!)
Bear in mind that these are the conditions that are personal to my current environment + are used as a guide for you to compare with your own home. It’s important to also remember that windows can be pretty different in size + if you live in a built up area, with other buildings close by, or if there are obstacles like trees outside, this all has an impact on the intensity of light.
When the plant is actively showing signs of growth, I generally water my plant around once a week in my current conditions. I allow the top layer of potting mix (1 inch or so) to dry out between waterings + have found the easiest way to judge the watering needs of this one is by simply picking up the pot! Compared to other houseplants, the delicate foliage, coupled with the small root system means that the plant will feel very light to lift up when watering is needed. Over winter, be sure not to overwater.
Asparagus ferns have bulbous roots which store the water (see photo below), meaning they don’t require as much watering as you might think + can tolerate periods of neglect.
Overwatering, particularly coupled with heavy potting mix can be problematic + cause these tuberous roots to go mushy + rot. If you struggle to get your houseplant watering right, a hygrometer can help to judge things. In terms of watering, remember that tepid (room temperature) water is always best for your houseplants as anything too cold can shock them. If it’s in one, take your plant out of the cache pot + water thoroughly until water runs out of the drainage hole. It’s not a good idea to let your houseplants sit in water inside their pots, or if your planter does not have a drainage hole, be careful of overwatering!
Consistency will help to keep your plant happy long-term so a good way of maintaining a workable care routine can be to place plants with similar care requirements together. For me, I have a few trailing plants displayed together that generally need a weekly watering, but always be sure to check before giving your plants a soak. Asparagus ferns don’t like to dry out + will often develop brown or yellowing foliage if the potting mix has become very dry.
Humidity + Leaf Care
Moderate humidities are favourable + will help keep your Asparagus fern growing healthily — a bathroom or a kitchen environment will often have higher humidity levels + can result in faster growth as a result + these conditions will also help to keep your plant a lovely rich green colour if the light is also softer. As I’ve noted above though, these plants are adaptable + can handle typical home environments well, without the need for any supplemental humidity. Look out for any draughty locations that might be too close to open windows or heaters + try to avoid any sudden drops in temperature. Asparagus ferns grow best in temperatures between 12-25°C.
Leaf care can often be neglected somewhat in plants with more delicate foliage like this. But just like other houseplants, dust build up can stop your plant from looking its best. I always notice when my Ficus elastica + Monstera leaves need cleaning as they have large leaves which show up the dust more clearly than these wispy, whimsical types! So even though it might not be quite as visible as on larger-leaved plants, giving your Asparagus ferns a gentle shower can help keep the foliage clean + dust-free.
I’ve found that my Asparagus ferns respond well to regular fertilising when they are in a period of active growth. Regular feeding can help to keep your plants healthy + strong — I fertilise my Asparagus ferns twice a month with a balanced liquid houseplant feed at half the recommended dilution rate. As a plant that gets watered regularly you’re unlikely to encounter any problems with fertiliser burn, but as a precaution, be sure to check the potting mix is not excessively dry before feeding. If your climate is quite different to mine + your plants grow consistently year-round, then more regular fertilising is absolutely okay — the easiest way to judge whether or not to feed is if your plant has new leaves growing!
Giving your houseplants the correct care is the best way to keep them resilient to any potential pest pressures but the most common reason for a pest outbreak is often as a result of incorrect care alongside very low humidities, coupled with high temperatures. Air flow is important too + Asparagus ferns are always happiest when given room to breathe as their foliage trails, so don’t cram it on a shelf with little breathing room as this can potentially be favourable conditions for pests.
If you are new to plants, it’s always best to take time to consider what types of plants will work for your lifestyle + importantly, your household conditions. Pests to look out for with Asparagus ferns are spider mites, mealy bugs + scale. Also, brighter light locations can also exacerbate any lurking pest problems + if you have a recovering plant, it’s best to keep in a more ambient light spot. When I bring a new plant into my home, I will always quarantine it for a few weeks + give it a thorough inspection in good light + often a soil change before introducing it to my other plants. As I have a lot of plants, this is an important step in ensuring my collection is not compromised by pests brought in by new plants + it’s totally worth the slight inconvenience of having a ‘new plant gang’ hanging around on the kitchen table.
If you have noticed a pest problem, an insecticidal soap spray + bath (roots + all) is a good starting point, before showering down. After any treatment, I like to use SB plant invigorator either as a ready to use spray, or you can also get a concentrated bottle to dilute into a spray bottle yourself, but be extra careful on more delicate foliage + always test a part of the plant first. I would spray all over the foliage of the Asparagus fern, but be careful to keep out of direct light as the leaves will be more sensitive after any pest treatment. I’ve also used a neem oil solution in a spray bottle which is also very effective for something more widespread, or if it’s something very minor, a Q-tip dipped in rubbing alcohol can also work, but of course, with the delicate foliage, can be difficult. It might sound unconventional, but beneficial insects can really help to bring a more widespread outbreak under control + are becoming more widely available as a method of pest management, but I have not tried this myself. When I’ve had a pest issue with my plants, I always isolate them for a number of weeks in my kitchen/quarantine zone + monitor before reintroducing near my other plant gang. If you discover a pest issue, it’s always best to carry out a thorough check of any pots that were located nearby, or any ones that are generally more sensitive to an attack.
The best type of potting mix that I’ve found to work for my Asparagus Fern is a free-draining light + airy mix of peat-free houseplant compost, perlite + orchid bark. I’ll pop a link here for the blogpost + component parts I use here. A common problem is that some plants can be in poor quality soil in their nursery pot, which is often too dense for the plant to be happy long-term. This can mean that the potting mix will stay saturated for longer than is best for your plant, so getting to understand how soil amendments can benefit your plants is key in keeping your houseplants happy.
A NOTE ON POTS:
The type of pot you choose to use is also intrinsically connected to your mix + watering requirements. For me, I prefer to use nursery pots with the majority of my houseplants because I find they dry out far too quickly in terracotta. Terracotta is much more porous + will wick the moisture away from the plant. If you want to use terracotta for display or plant styling reasons, you can always use the terracotta as a cover (cache) pot. This is personal preference of course + if you are a big time over-waterer, you actually might find terracotta can be corrective in helping to manage your over-zealous watering efforts! But it’s a hard one to judge so be careful with plants that require more frequent watering such as this one.
Asparagus Ferns grow best when slightly root-bound + only need repotting every 1-2 years as they have a small root system. I prefer to wait until my plant is actively growing before I start repotting, so early Spring or Summer is ideal. Just going up one pot size is best too — no big jumps in size. Loosen the roots gently with your hands, being careful of not damaging the tuberous parts when doing so. Before any repotting, it is advisable to water in the few days beforehand to prep your plant for it’s pot upgrade.
Plant display, propagation + pruning
Because of their delicate appearance, Asparagus ferns can look equally great as both a large, mature plants with cascading foliage trailing from great heights to when they are kept in smaller, more delicate pots, tumbling off a bookshelf. If you have some of the plants in this group, you’ll know that the way the foliage grows is pretty unpredictable! Over time, heavier stems will hang down with their own weight, but new growth can often look like its defying gravity as it grows upwards + outwards. This means that you might decide to tailor how your plant looks by a bit of pruning, but propagation is another easy option that will also increase your stock (for free!). The best way to propagate an Asparagus fern is by division — when you take the plant out of it’s pot + loosen the roots, you’ll be able to observe that the growth can be quite easily split/divided into ‘clumps’ of plant if you carefully loosen the roots adequately. You’ll then be able to pot these up as you wish.
In terms of pruning, feel free to chop + give your plant a haircut as you wish! But watch out for sharp spikes + be aware that the stems will become woody as they mature — it’s a good idea to wear gloves when chopping this plant. Always use a sharp, sterile blade to prune + clean between pruning different types of houseplants too. Trim stems a few centimetres above the potting mix. Pruning can help your plant work well in any space + can help with airflow too if growth gets a little dense in parts.
So there we go, hope you liked this plant care post today + thanks so much for your recent blogpost requests. You’ll be able to find this post under my ‘Plant Care Guides’ tab on my homepage if you wish to refer back to it + here are some pins to share or save too:
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