Whether used to scent tea, rice or perfume, jasmine has a rich, sensual floral scent that many appreciate. While most flowering plants aren’t easy to grow at home, several varieties of jasmine have proved themselves as houseplants for sunny corners (or, even better, for those lucky enough to have a cool greenhouse). Here’s how to grow your own indoor jasmine!
Origin
There are around 200 species of jasmine. They are cultivated for the production of their flowers, but also as ornamental plants in tropical countries. Only a few of these species are used as houseplants. (There are also several plants mistakenly called jasmines, but only plants in the Jasminum genus are true jasmines).
True jasmine is therefore a member of the Oleaceae family, which also includes olive (Olea), lilac (Syringa) and holly (Osmanthus). Jasmines are found naturally in tropical and subtropical regions – from Asia and Africa to Oceania and Europe. This explains why different varieties of jasmine require different care, as they are found in a wide variety of climates. Jasmine has become naturalized around the Mediterranean basin and the Indian subcontinent. Unfortunately, some varieties have been recognized as invasive in Hawaii, Florida and Australia.
Jasmine is the national flower of Tunisia. In Pakistan, the national flower is the white jasmine (J. officinale), while in the Philippines, it’s the variety known as Arabian jasmine (J. sambac). One of Indonesia’s three national flowers is also the sambac jasmine. The flowers are often part of bridal bouquets in some Asian countries.
Description
Most jasmines are climbers, but some are also sarmenters, meaning they grow in all directions, hoping to find a support to get as much light as possible. When jasmines are climbers, they manage to attach themselves thanks to their voluble vines, which twist around the branches and trunks of other plants in the vicinity. The stems eventually become more rigid and produce bark. A jasmine can become quite an imposing plant, up to ten meters high with a spread of four meters. Tropical jasmines are evergreen. The leaves of some, like J. sambac, are oval and opposite on the stem, while others are imparipinnate, so each leaf is divided into 5 or 7 leaflets (for example, in J. officinale and J. polyanthum). Subtropical jasmines lose their leaves in the colder months.
Flowering
Most jasmines bloom happily – in fact, they’re what the plant is known for! The traditional flower is white, star-shaped, with five petals. The buds are white or pinkish. The flowers release their fragrance at night, to attract nocturnal pollinators such as moths (which see the flowers better in the dark when they’re white, of course). The flowers, used in the creation of the precious jasmine essential oil, must be picked at night to maximize their use; the essential oil is also quite expensive, as many flowers are needed to produce it.
Yellow flowers are seen especially in the less tropical varieties, which are then nicknamed “winter jasmines”. However, it’s easy to get confused, as some jasmines that are flowered indoors during the winter are also called “winter white jasmine”… In fact, in nature, jasmines flower in late spring or early summer. In the home, most will bloom in winter, as they interpret the slight autumn chill as winter and start producing buds for spring, which in their native countries occurs only a few months after such a chill. Unfortunately, no jasmine is ready to survive the winters we experience in Canada, let alone those we use as houseplants!
Varieties
Jasmine has been cultivated for a very long time, and has long been appreciated by gardeners. In fact, it’s hard to say exactly when jasmine cultivation began.
Since the various jasmines grown indoors sometimes require quite different care from one another, they will be presented after the section on basic growing tips.
Growing Tips
Light
Indoor jasmines can survive as a foliage plant in constant bright light, but they can only flower when they are under intense light, with direct sunlight. They don’t mind the heat of the hottest windows.
Watering
Jasmines are fast-growing and prefer constantly moist soil (but not swampy soil – watch out for stagnant water at the bottom of the planter or saucer).
When they are not growing, i.e. mainly during winter or when light and temperatures are low, their need for water is very low, and you can wait for a few centimetres of potting soil to dry before watering.
That said, once the buds have formed or the plant is in flower, jasmine’s water requirements increase exponentially. This is particularly true for plants that produce a profusion of flowers, such as J. polyanthum.
In general, then, jasmines are rather thirsty.
Atmospheric Humidity
Jasmine tolerates the dry air of our homes well, but prefers more humidity.
Potting Soil and Repotting
A standard indoor plant potting soil is well suited to jasmine. Although it grows quickly, it accepts – like many other climbing plants – a little cramped conditions in its pot before repotting is necessary. It’s only when the gardener can’t keep it sufficiently moist that the pot size needs to be changed.
Fertilizers
Un engrais tout usage lui convient durant la période de croissance.
Temperature
Most jasmines tolerate indoor temperatures of between 16°C (60°F) and 24°C (75°F).
And Out of Doors?
For gardeners lucky enough to live in warmer countries, jasmines are much easier plants to grow outdoors. They thrive in full sun or light shade (which can reduce flowering intensity) and require regular watering, as they have a medium tolerance to drought.
Otherwise, they don’t necessarily have disease problems and require no special care. They are occasionally attacked by aphids, especially on new shoots.
Most white-flowered jasmines are tropical (zones 9 to 12) and those with yellow flowers are a little hardier (up to zone 7, but winter protection is probably necessary). Of course, each jasmine has its own particular cultivation requirements.
Beware of jasmine used in the garden: it can quickly become invasive.
Care
Now let’s get back to growing jasmine indoors.
Without sufficient light or humidity, jasmine growth can be etiolated; pruning the terminal shoots stimulates branching and a denser habit. (Be careful not to cut off a branch bearing buds).
After flowering, the dried flowers can be removed; otherwise, they will eventually dry out and fall off on their own.
It’s best to take jasmine outside in summer to take advantage of the increased light and humidity.
As most jasmines are climbers, or at least sarmentous, it’s best to control their overflowing growth with a stake. It will probably be necessary to tie the voluble stems, but not too tightly.
Propagation
Jasmines can be propagated without too many problems by taking stem cuttings.
Problems
- Pests that can affect jasmine include mealybugs, spider mites, thrips, whiteflies and aphids (the latter are more prevalent outdoors).
- Leaf drop: this means either that the plant doesn’t get enough light (quite common when brought in after spending the summer outdoors) or that it has been over-watered.
- Leaf yellowing: the plant is under stress, which may be due to a sudden change of environment, excessive atmospheric dryness or a watering problem. Jasmines are also rather fond of nitrogen (the first of the three numbers indicated on fertilizer packaging) and yellowing leaves may be due to a lack of nitrogen. On the other hand, it’s best not to immediately fertilize a plant that has just suffered a shock.
- Downy mildew: this fungus affects the leaves and leaves a kind of white powder. It’s best to remove affected leaves or treat them with a fungicide. It may be beneficial to increase air circulation to prevent the reappearance of mildew.
Toxicity
Jasmine is not toxic.
If you want to use the flowers to make tea, for example, it’s best to pick them at night, when they’re at their most fragrant. The swollen, but not yet blooming flower buds are then picked. On the other hand, remember that purchased plants are not necessarily produced for consumption: make sure you choose a plant that you are certain has not been fertilized with potentially harmful products or sprayed with pesticides.
Buying Advice
As with other flowering plants, choose a plant with an abundance of buds and only a few flowers already open. This will ensure a longer period of fragrant flowering.
Where should jasmine be placed in the house? Ideally, in the sunniest window. If, as in my case, it’s the bedroom window, here’s a little article on fragrant flowers in the bedroom.
The Question of Bloom
How do I get a jasmine to flower? Most indoor jasmines have fairly simple flowering and resting periods. Typically, they form buds and bloom in winter, continuing their show into autumn and early summer. Towards the end of summer, they rest or concentrate on their growth and, in late autumn, resume this cycle. There are, however, several conditions that favor more spectacular flowering.
The first is to make sure the jasmine gets enough light to produce buds, which means putting it as close as possible to the sunniest window.
Then, a few weeks in a cool place (no less than 15°C, 59?) in autumn helps the jasmine to “know” that it’s time to rest, enabling it to resume flower production. These temperatures can be reached by leaving the plant outside at the very beginning of autumn (be sure to keep an eye on night-time temperatures!) or in a cool greenhouse. On the other hand, avoid dark garages and basem*nts: the plant is not completely dormant, but still needs light.
A phosphorus-rich fertilizer is ideal for flowering plants. To determine whether a fertilizer is rich in phosphorus, look at the three numbers on the packaging (NPK): the first stands for nitrogen (N), the second for phosphorus (P) and the third for potassium (K).
Finally, you need to concentrate on light: jasmines are short-day plants. Like Christmas cacti (Schlumbergera) or kalanchoes (Kalanchoe), you need to be careful not to keep jasmine in a room with artificial light in the evening. If you’re having success with flowering these plants, remember that jasmine is less dependent on short days than the others.
Note that jasmines flower on new wood: a little regular pruning keeps them compact and stimulates flowering. It’s best to prune at the end of flowering, but before the resting period. The question of flowering is a delicate one, and almost all jasmines have their own particularities. The following section looks at the different varieties in more detail.
Indoor Varieties and Special Growing Tips
Three main varieties of jasmine are grown indoors, although other varieties are also commercially available.
Jasminum polyanthum
The most commonly seen jasmine is Jasminum polyanthum, or many-flowered jasmine. It’s also called pink jasmine, but it’s not the flowers that are pink, only the buds. It can be recognized by its leaves with five or seven leaflets, reminiscent of the fronds of a fern. This is the easiest jasmine to keep indoors; it grows relatively fast and can reach quite impressive sizes. With a regular trim, branching is easy and the plant is attractive all year round.
This highly floriferous jasmine produces clusters of long, slightly pink buds that open onto star-shaped flowers with five white petals. They are extremely fragrant and may even be a little too intense for some people, especially in the evening or in a closed room. Flowering usually lasts a few weeks, in winter or spring. The water requirements of this jasmine are particularly high during this period: it may need watering several times a week, and its potting soil should never dry out.
The main difference between Jasminum polyanthum and other jasmines is its need for cold to flower. It is best to keep it for around six weeks at temperatures between 4°C (39°F) and 15°C (59°F). Moreover, this jasmine prefers a cool spot in the house, with temperatures between 13°C (55°F) and 18°C (64°F) at all times. This allows its blooms to last longer. On the other hand, despite its tolerance to the cold, it does not tolerate frosts.
Jasminum sambac
Another jasmine grown indoors is Jasminum sambac, or Arabian jasmine. This plant has a more shrubby habit than other jasmines, forming a small, sarmentose bush rather than a proper climber. It can be recognized by its oval leaves, which distinguish it from other jasmines whose leaves are often divided into leaflets.
Arabian jasmine is definitely tropical and thrives in warm temperatures all year round. It doesn’t tolerate temperatures below 15°C (59?). It doesn’t really need a resting period and tends to flower sporadically all year round.
There are a number of sambac jasmine cultivars, such as ‘Maid of Orleans’, with single, highly fragrant flowers; ‘Belle of India’, with single, double flowers and elongated petals; and ‘Grand Duke of Tuscany’, with particularly large flowers resembling small roses, but less fragrant.
Jasminum officinale
The last easy-to-find jasmine is Jasminum officinale. It has pinnate leaves resembling those of J. polyanthum, with up to 9 leaflets. Its star-shaped white flowers are also larger and more fragrant. Also known as common jasmine.
This jasmine is something of a blend of the two jasmines mentioned above. It doesn’t need as long a cold spell as J. polyanthum, but it still requires a little rest in a cool place. It can then be kept at normal house temperatures. It tolerates temperature drops better than J. sambac, but should still be kept above 13°C (55°F).
A few cultivars of the common jasmine have made their appearance: ‘Devon Cream’ or ‘Clotted Cream’ has flowers with petals so wide that they pile up on top of each other; ‘Inverleith’ has red buds (but white flowers); the foliage of ‘Fiona Sunrise’, ‘Frojas’ and ‘Sunbeam’ is entirely chartreuse (particularly visible on new shoots) and, finally, ‘Argenteovariegatum’ has variegated foliage.
Other Outdoor Varieties
Apart from these three varieties, other jasmines are rarely used as houseplants. There are, however, some noteworthy varieties.
If these varieties can’t be grown indoors, they can be kept alive over winter by growing them in a cold greenhouse and bringing them out the following spring. However, these are not plants for home gardeners, let alone laidback ones… I’ll stick to the three indoor jasmines mentioned above!
False Jasmine and Other Perfumed Impostors
There are other “jasmines” that are grown indoors, but aren’t really jasmines.
Conclusion
Although I don’t think it’s wise to produce tea from it, the fact remains that jasmine can act as an attractive plant whose fragrant flowers will delight the senses. It’s certainly not the easiest or most difficult of houseplants, but its cool resting quirks are well worth it once its white flowers start to spread their fragrance!
