salpiglossis

A Comprehensive review of all the wrong ways to grow Salpiglossis found on the Internet.

Maybe you’ve never noticed it, but a lot of information found on the internet is sometimes incorrect. After spending a week researching how to grow salpiglossis, or Bearded Tongue, an old fashioned and rarely seen annual, I discovered that all my information that I once so trusted might have been wrong all along. My advice to you? If your source for information regarding seed starting does’nt show pictures of the process and their results from the methods they are suggesting, question the method. Today, I look at some more unusual annuals – specifically Salpiglossis. A notoriously fussy annual to grow well (although there is no shortage of on-line influencers stating that it’s ‘Easy and Fun to Grow!”. Since you’ll see advice ranging from sowing it in milk jugs set outdoors to sowing it directly into the garden, to sowing seed only after refrigerating it, allow me to set some myths straight here. For now, set aside the advice found on the seed packet and let look at the plant a bit closer.

Salpiglossis raised and displayed at Longwood Gardens in 2018. Salpiglossis often perform at their best under glass as a spring flowering display crop for conservatories, but most of us will be growing it in the garden.

On a single afternoon, while double-checking cultural information found on a seed packetfor salpiglossis, I became confused. I had been working with some known facts, though. Mainly that Salpiglossis was one of those plants whose seed needed to be germinated in complete darkness, and most internet searches confirmed this. At least, at first. It wasnt until I started looking at some older books, a few new seed packets and then newer books when I became really confused. I even found contradictory information found on the same seed packet – so I went down the rabbit hole on a journey to find the best source for how to grow salpiglossis. I should add, that I also will provide the right, or perhaps better way to grow salpiglossis from seed. It wasnt as easy and as clear as I thought it would be.

Truly an old-fashioned plant, salpiglossis, or Bearded Tonge, was once a considered to be a cool greenhouse crop for late winter or early spring bloom. It can excel as a garden plant though, or even better in large containers but careful seedling handling is required. Since all salpiglossis must be raised from seed (ideally, at home and not in the way that a bedding plant might be treated at a garden center) you can achieve a similar look. These are truly a plant for capable growers who are willing to follow directions, and to perhaps toss aside some old, out-of-date advice that keeps circulating about their culture from seed.

Look, I get it. Who wants to actually grow salpiglossis? So clearly, this post is for those who are bored with what they are growing, or who may have failed with salpiglossis in the past, or for those who might be trying to grow them for the first time and who ended up here from an internet search (I hope so – as not only are salpiglossis worth growing, you are going to become totally confused if you start looking for advice elsewhere.). Those who know of me, know that I try everything myslef until I can master it. I’m never going to just wrtie about how to grow a plant from information that I found on an internet search. I only will write about it if I can provide photos of my own studies and attempts (and sometimes failures) and never will I write about it unless I’ve tried and tried again to grow it well. My guess it that most people providing advice have not grown salpiglossis from seed. Just a guess.

A large container with a single selection works best for salpiglossis. Always stake, even in the garden with small bamboo or twigs as stems are naturally flexible. These, at Longwood posted by a student show how lovely a mass of salpiglossis can look.

Just try this yourself. Google the phrase, “How to grow Salpiglossis.” Most of the advice, at first, will all sound the same. But look deeper. In the past, while I found all sorts of advice I eventually settled on what I felt were my most trusted sources, both of which suggested that the seed of salpiglossis should be surface sown, and covered until it germinates and both included the unusual method that Salpigossis must germinate in complete darkness. An odd bit of advice, for something that needs to be surface sown, but why argue with the experts? I mean, other plants within Solanaceae sometimes need darkness to germinate – at least it;s been proven for Schizanthus, for example – and thy too are from this part of South America. It must be true, right? Not exactly.

Ive grown Salpiglossis on and off through the years, always following the advice provided in my go-to book on growing plants from seed – the late Wayne Winterrowd’s (not out of print: Annuals & Tender Plants for North American Gardens). Still, an excellent source, but clearly he too found the same incorrect information for Salpiglossis, as it’s often repeated in old gardening texts – I mean the most trusted books. Yet I always get confused with the ‘surface sow, but in darkness” method. It just doesn’t make sense. Still, I know that a few plants do require this – most are desert plants (some cacti) or others where the seed falls deep into rocky crevaces, where it might be dark. In it’s native habitat, it appears that Salpigossis does grow in a harsh, if not unique environment with rocky soils that experience frequent mists, but still, with all of my research, I could not find any factual information. To make matters worse, the deeper I looked the more contradictory information I found – usually from seed catalogs. everything from sowing deep, to surface sow. SOme advice refrigerating seed, others, not. Again, this idea that seed must be surface sown yet kept dark -(as the belief is that light inhibits germination) was always problematic for me. Tiny seeds means tiny seedlings, and more often than not, they stretch out so quickly – even in just a day or two if I cover the trays with black foil – that the resulting seedlings suffer. Then, last year, I decided to research they ‘why’ and where’ about such advice. As I usually discover, the answer is never clear.

Old and new selections exist, some with interesting colors that might make salpiglossis worth considering again, but know that they are not the easiest to grow from seed. That said, they are growable, but finding accurate advice can be hard.

I will spare you all of my discoveries, but I will share right now that my two most trusted sources advice the exact opposite treatment. Mainly, the culture sheets provided by the largest seed producers available as downloadable PDFs to professional growers, and from an old yet very accurate germination study book – both clearly state that Salpiglossis will germinate at 70° F with bright light and a light covering of a substrate. No chilling of seed, no blocking out of light. I will add that this is not unusual with hybrids, which all Salpiglossis seed is today. The darkness/surface-sown method might be required for the true species if collected in the wild.

A simple grandiflora mix will often result in a range of colors that can include a harsh yellow, but also pretty purple tones.

About Salpiglossis

Salpiglossis or Bearded Tongue is not a commonly grown annual flower. I think for a number of reasons, it’s fallen out of favor, which I understand from a mass-market perspective. Most casual gardeners might not be interested in growing them, for they arent going to put on a show all summer long with no care needed. Yet, there are some of us who either through boredom, or curiosity, do want to try something different. So we try things that are new, maybe just because we’ve never really seen them offered at the garden center, or maybe because we’ve never even seen one except in a photo and salpiglossis is one such plant. My theory is that they remain uncommon for a couple of very good reasons. 1. Even if you find plants available at a good garden center, they never really take-off in the garden. and 2. The seed is fussy. Regardless of what you read on a post or on social media, Salpiglossis is not ‘easy to grow’ (it’s not impossible, but it’s not easy).THat said, they are certainly growable. If you’re capable of following directions (yes, just like making puff pastry) you can do it.

Salpiglossis seedlings from a winter sowing can grow floppy unless one can provide long day length (14 hours) and brightest light conditions. These were in my greenhouse in March, and grew more lanky than they should have. I now keep young plants warm, under lights indoors where the light intensity will cause rosette foliage to first form.

A true old-fashioned annual, Salpiglossis was first introduced to North America in the early 1820’s so it isnt exactly a new flower. Paxton’s Dictionary described the earliest collected species (S. sinuata) in 1823 and shortly after, in Curtis’ Botanical Magazine in 1826 wrote about plants being bloomed in England. This species is still the major parent from whichmost hybrids come from today come, although there have been some complex hybrids. Early 19th c. selections (such as the now lost ‘Barclayana’) were pale yellow with plum and brown stripes, similar to the wild species. An early hubrid from England ‘picta’ which expanded on the pale yellow with lum purple stripes and S. straminea (Hooker) which was described as being distinctive purple-red stripes on a creamy-yellow base in 1834 near Edinburgh. Most of these descriptions still sound and look (in engravings) like earlier selections made from the wild species, which can range from a silvery-cream base with violet stripes to a deep plum color and golden throats. I would add that one new selection (now hard to find) named ‘Gloomy Rival’ looked rather similar to the wild forma and the branchy, smaller flower might be the new trend – especially for floral designers and garden designers. I know that I prefer this habit, and I’;m hoping that new selection like ‘Cafe au Lair’ first offered this year, will provide.

By the turn of the 20th century, early hyrbidisiers transformed the species into what we today (or maybe what our great grandmothers’) would still recognize as a salpiglossis. The new hybrids haven’t changed much in 100 years. The color palette was broadened around 1900 to include bright golden yellow, deep plum and velvety purples, maroon, orange, red and magenta. All with a golden or veined, netted throat that is often striped brown. Honesty, an odd color palette when viewed together in a garden bed but rather lovely when viewed in a conservatory or greenhouse when grown as a potten plant. Maybe because one can organize the pots better by color.

Today there are a handful of selections that remain on the market, and occasionally a few new selection – two that take advantage of the current trends and style of brown and grey flowers. (the newer introductions that are brown, tan or buff, in particular, a new selection from the Japanese firm TAKII called ‘Cafe au Lait’ (name a salpiglossis after the world’s most popular dahlia and maybe it’ll become popular?). It can be found from a few seed sellers this year (Baker Creek and Select Seeds). Some of the darker-flowers salpiglossis, often marketed as ‘near black’ are unsuccessful in the garden (retreating into negative space and shadows) but as a cut flower or as a potted plant, they are effective. I’m not convinced that Salpiglossis will ever become a popular cut flower crop though as the stems are sticky (like nicotiana) but is used correctly, they might be of interest.

Not judging, but sometimes (more often than not) growing advice can range from sowing seed deep, to surface sown, to refrigerating seed and more. Often on the same seed packet or from the same seed catalog. Know that cultural information can come from freelance writers, or elsewhere and often not checked. I discovered three sources with the exact wording from different seed catalogs suggesting that a third party may have offered advice, or that it came from the seed multiplier company. My point is to always question advice today.

How to grow Salpiglossis

Sowing Seed

Contrary to what you may read, salpiglossis does not need complete darkness to germinate, nor does it need to be surface sown. Ideal methods advise one to sow seed either 1/8″ deep or surface sown but covered with a medium like vermiculite to 1/8 deep. Some light should still be able to reach the seed, as intense light encourages seed germination. Start indoors, in warmth around 70° F. No need to refrigerate or chill seed. Salpiglossis demands intense light (2000-3000 foot candles) so I move my High Intensity full spectrum LED light close to the pots. Sow seed thinly, either in plug trays, flats in rows or in 3 inch potsSown this way, seeds germinate in 4-5 days. Quicker if you cover the seed pots with plastic wrap to increase humidity.

Seedlings can be transplanted once they have formed true leaves into individual cells, modules or 4″ pots. Ideally, if gown cool and allowed to dry out between watering these tricks will control size, speed of growth and to stimulate seedlings to form rosettes of foliage which is ideal. This form will naturally happen if you sow plants in late summer for use as a winter potted plant in a cool greenhouse, but spring grown plants for early summer blooms will still benefit from a wet/dry wet pattern until the plants are set out into the garden in May. Nursery plants are often mis-grown, treated as petunias or other bedding plants in 6 packs. Retailers want to bring them into bloom while still young as most people are not familiar with what they are buying, or want certain colors. If you happen to find salpiglossis at your garden center, try to buy plants that have not yet begun to bloom or ideally, ones that have not started forming a stem yet. These, if set out into the garden will produce the longest stems with branching. ,

Young Salpiglossis seedlings in the greenhouse from last year. As I said above, this year I will keep seedlings indoors under lights until late April to maintain longer days and continual warmth. Also, it will allow me to practice the wet, dry, wet soil cycle so helpful for encouraging proper growth.

Growing-On

If growing at home, spring can be challenging especially in a greenhouse as one sunny day can raise the temperatures into the 90’s which will harm or set-back many South American annuals like Salpiglossis, schizanthus and others. Strive to keep plants cool, not cold and not hot. Try to get pots to sit at 55 – 65° for as long as you can, but always in bright light or full sun. I often just keep my seedlings in 3 inch pots (one per pot) under lights in a spare bedroom until April, as I can control the temperature more with less differential from day to night. Salpiglossis seedlings will suffer if they experience temperatures above 85° F until they reach blooming size. Once in the garden, I’ve had plants survive through 95° F weather. Always try to provide a larger pots for unrestricted root growth, as with nicotiana, as well as a higher and more frequent fertilizer program than you might be comfortable with. Until set into the garden, practice the drying out between watering method as one would do with snapdragons and pansies. This, combined with a continual warm environment will help plants stay bushy and not elongate too much. Once plants begin to show flower buds, then switch to a watering regimine that is more constant – never allowed to dry out, and always move dead blossoms.

A nice, dense rosette of foliage with a seedling grown in bright light, under LED lights set at 16 hours, in this case. A rosette of foliage will stimulate a salpiglossis to produce multiple stems. Botanically, the plant is considered to be somewhere between and annual and a perennial, often considered a tender perennial or a short-lived perennial, like snapdragon. Autumn grown plants in milder climates like California, or in cold greenhouses for spring bloom will also form rosettes like this in late summer/autumn,slowing down in winter, but producing multiple flower stems that are tall in early spring.

Salpiglossis grow best in areas with cool summer temperatures. Here in New England they do well in most summers even though it can become very hot and humid, but home-raised seedlings are the most resilant. FInd a location where plants can get partial sun (just in the morning or a few hours in the afternoon) as that would be an ideal location. Soil should remain goldilox moist, not soaking wet, nor allowed to dry out completely, ever. This might explain why my potted Salpiglossis (especially in the fall and winter when they are in the greenhouse) seem to perform much better than those set out into the garden in summer and grown as one might grow zinnia or cosmos. We don’t have an irrigation system, but a drip irrigation system might be ideal here as long as it doesn’t get too wet.

Fertilize

I tend to look at commerical culture sheets showed me that as with snapdragons, fertilizer makes a huge difference with the success of a Salpiglossis crop. I should have figured this out on my own, for the entire group of solanacea are fussy about fertility. This also includes petunia, snaps, Schizanthis and even unrealed Violas or Pansy. Home grown from seed plants rarely will look as nice as nursery plants for this very reason. These are crops that all require special fertilizer. You can’t just say “Ill grow organic’ or ‘Ill just use fish emulsion’. These are crops that demand specific micro nutrients, and low or high amounts of key elements. They all require a low phosphorus fertilizer (like Peter’s Petunie FeED which you can find in smaller containers on Amazon). I always get a small container but this year I orderd a larger bag by another manufacturer for use on all of these seedligns. I was getting sick of raising snapdragons that had toothpic thick stems, always feeling inferior to those pencil thick stems I woudl see at the garden center.

IN my summer garden, carefully grown plants will grow tall and are stunning with partial shade, and the setting sun turning each flower into a stained glass window.

Peters Petunia FeED is just a suggestion (and know that there are other petunia feeds by other brands) all include chelated (ED) iron (the Fe) and other elements not found in most fertilizers. I think most people don’t know that the big wholesale growers have this all figured out, but a search of the various mixes on a greenhouse site will show you that you don’t – just look for a lower second number in the analysis like 15-5-15. Most annuals will grow just fine without fertilizer, or with a balanced one ,even one with high nitrogen like fish emulsion, but when it comes to a few like petunia, callibrachoa, pansy, snapdragons and related clan – it’s all about the CalMAG types of feed. The micronutirents found in specialized petunia fertilizers are chelated manganese, zinc and copper. Chelated minerals like these, while costly to produce, are essential for good plant growth in these plants within solanaceae but also with pansies. It might seem crazy to buy a specialized formula, but the commercial growers all do, so it’s good to know.

FACT RECAP

Sow Salpiglossis in mid-February indoors, under lights at 70° F. Cover lightly with vermiculite.Light benefits germination with Salpiglossis (<2500 F.C), so only cover seeds lightly

Do not refrigerate seed, no need for con stratification (although wild collected seed might need chilling).

Keep seed trays or pots warm, 68-72°F directly under lights – take care if using a heat mat. Cover with plastic wrap to increase humidity

Use a timer on your lighting unit as salpiglossis requires day length greater than 14 hours, and 16 hours is ideal. This will greatly improve seedling quality and reduce stretching.

Once cotyledons unfold, begin to withhold water, almost wilting between watering. This is an important step that commercial growers practice as it reduced floppiness and encourages growth that is sturdy. Salpiglossis trays should become dry between waterings.

Begin feeding seedlings with a 1/2 strength 15-5-15 bi-weekly. Propert fertility is key with salpiglossis in cultivation.

Try to offer plants the absolute brightest light you can as plants mature. 3000 F.C. is ideal, or keep trays close to HID bulbs, or greenhouse.

Location, site and containers

Salpiglossis was often grown as a fall container crop for displays especially in late winter and early spring in estate conservatories and botanic garden greenhouses. Today this is rarely practiced but occasionally you may see them at good botanic gardens like Longwood where capable gardeners can fuss with them.

They do make excellent potted plants in winter for cold greenhouses, but even better in large tubs outside. Salpiglossis will naturally perform best in areas with cool summer temperatures (Vancourver, Atlantic Canada, Maine) but also as a winter bedding plants in California or Arizona perhaps. Elsewhere, we try it every other year or so as. garden and potted plant (potted together by itself as a specimen plant, not combined with anything else). In New England it perform well if one can obtain properly grown seedlings that have not yet formed flower buds, and are small enough to transplant into large tubs or the garden. I grow large colonies in our Painters Garden, which receives partial shade and the plants bloom all summer long, reaching 24″ high. The hummingbirds can’t resist them.

In the garden they perform best with partial shade in our humid climate where it can become very hot (90° +). Excellent displays often peak around mid-July and fade off unless the flower stems are cut back, only then will a repeat bloom happen in September, but usually we just pull the plants. Few annuals offer the grace and colors that Salpiglossis can, and if sited where the setting sun can back-illuminate the flower the trumpet shapes can virtually glow where the golden throat pattern looks as if its an electric light.

‘Kew Blue’ is a stunning, dark purple but these dark colors often look better in containers than in the garden as the flowers can become lost.

VARIETIES

Most selections today are complex hybrids, they include:

Superbissima blend (not truly an heirloom, but from the 1980s)

Grandiflora Mix (a generic mix that usually is comprised of F1 hybrids

Friendship series

Royale Hybrids F1 (Floranova)- but offered by many retail seed sources

Bolero F2 A good performing blend

Casino Series – Perhaps the most popular with garden centers.

Splash Mixture

Little Friends (Sahin 2001) Shorter plant, bushy, for bedding

Cultivars :

Kew Blue (introduced in 1985 Sahin) – a nice, need purple, but use it carefully in the garden as it is very dark. Better in pots.

Black Trumpet(Baker Creek)- So tempting in photos, but rather blood-red if not a dried meat blood color in the garden..

Wild Grape’ – Annies Annuals -Reportedly from wild collected seed, but that’s questionable as it’s a selection.

‘Wild Orange’ Annies

Chilean Black (JL Hudson) – perhaps the same black as ‘Black Trumpet’

Cafe au Lait – fleuroselect  (protected for 8 years) new novelty color intro bred by Takii Europe. Marketed not as a cut flower or as a nursery annual, but strictly for home gardeners as a novelty color

Gloomy Rival – forgotton selection 2019 select seeds grey/silver petals. hard to find right now.

Some of the mussy colors can also be less attractive in person. This selection is nearly black in real life, but photographs maroon. It is practically lost in the border, but in a pot, especially if potted together with the same color, it can shine.

About the author

Author, plantsman, and horticulturist living in central Massachusetts.

Comments

  1. Matt, thanks for the in-depth intel on Salpiglossis! Is it recommended to pinch the main stem to encourage more branching and more flowers?

    1. I’ve done both this year, and I think it comes down to how tall you want your plants to be. Un-pinched they (so far) are 2-3 feet tall, and beginning to branch naturally. This might be the preferred way for growing plants as cut flowers, I would imagine. My pinched plants begin to branch lower, but the stems are not as long or strong. Of course, this is all anecdotal but my experience so far.

  2. Thanks, Matt. I have two plants from Bunker Farm Plants in early May. (So happy that Helen O’Donnell grows these so I don’t have to! Growing from seed indoors is not my thing). The plants are now a foot tall with only one main stem that has flower buds. I’m growing them for cut flowers to use in bouquets, arrangements, etc., so number of flowers and stem length are both important. I guess I will be patient and wait for them to branch naturally!

    1. Helen is just the best, isn’t she? Plus, it’s about the only place where you can find most of these plants that I talk about (the rare annuals). Walker Farm near her, also often carries good annuals like salpiglossis. I highly reccomend them.

  3. Super curious about chelated iron suggestion. It looks like this is not organic? Is it enough of a boost to just use iron or a natural amendment? I had great plants in 2021 and I’m kicking myself for not taking better notes!

    thank you for sharing so much!!

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