Bougainvillea


Bougainvillea spectabilis


Contents

  1. Top Tips
  2. Location, Water, Humidity & Fertilisation
  3. Dormancy Period & Annual Flowers
  4. Common Issues
  5. Origins, Temperature, Propagation, Repotting & Toxicity.


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Top Tips & Info

  • Care Difficulty - Moderate
  • Provide a bright location with a splash of morning or evening sunlight, but remember to avoid excessively dark areas for maximum flowering times and overall health. A semi-shaded conservatory is best for good, quality blooms. 
  • Keep the soil relatively moist whilst in flower, using lukewarm water. Reduce waters slightly in the autumn and winter to avoid over-watering and root rot - a common problem during its dormancy period. 
  • Feed at fortnightly intervals using a potassium-based feed (like 'Tomato' or 'Flowering Plant' fertilisers) during the flowering process, reverting to a 'Houseplant' labelled product at monthly intervals, soon after.
  • Scroll down to 'Dormancy Care & Annual Flowers' to learn more about annualising blooms.
  • Keep an eye out for AphidsSpider Mites & Whitefly that'll inhabit the cubbyholes of the stems and flowers. Click on the appropriate link to read more about each issue. 




Location & Light - 🔸🔸🔸

A sunny location with a few hours of sunlight is perfect for growth. Leaf and flower loss will occur when a Bougainvillea is situated in a too dark or cold setting. In terms of a place around the house, a location within two metres of a south-facing window or conservatory is ideal. Do not situate one within three metres of an operating radiator or in an area that doesn't offer enough light to read a newspaper.


Water - 🔸

Allow half of the soil to dry out in between irrigations, avoiding persistent droughts whilst the plant is in bloom. During the colder months, reduce this even further, to around once every ten to fourteen days. Bougainvillea grown in darker locations must be watered far less than with those kept in brighter spots to counteract the chances of rot. Their root systems can be rather sensitive to temperature change, so applying cold water may weaken the plant over time, along with reducing its growth rates in the spring. If you do decide to use tap water (instead of rainwater collected from outside or fresh bottled water), allow it to stand for at least 24hrs to eliminate the ironised chemicals. Under-watering symptoms include rapid flower or foliar drop, stunted growth and dry, crispy leaves; these issues are usually due to either forgetfulness, too much sunlight or heat. Introduce a pebble tray to slow the rates of drying soil and therefore, dehydration. Over-watering symptoms include rotting lower leaves or flowers, yellowing leaves, a loss of buds or flowers and root rot. Allow soil's majority to dry out in between waters, and do not allow a pool of standing water accumulate beneath the pot, as failure to keep its environment relatively dry will result in the disease stated above. Scroll down 'Common Issues' to learn more about addressing root rot.


Humidity - 🔸🔸

Average humidity found in a conservatory will do fine. Avoid misting the flowers as excess moisture left on the intricate bodies may cause botrytis petal blight. We'd recommend not placing yours in a frequently used bathroom because of the combination of moist air and potential air circulation issues, which could entice powdery mildew into play.


Fertilisation - 🔸🔸

Whilst the plant is budding or in bloom, supplement fortnightly with a potassium-based feed - a 'Tomato' or 'Flowering Plant' labelled fertiliser is ideal. Once the final flower has elapsed, revert to a 'Houseplant' feed at monthly intervals throughout the year. Do not directly apply 'Ready to Pour' liquid without a pre-water beforehand, as this will lead to the burning of roots.




Dormancy Care & Annual Flowers

Bougainvillea can produce beautiful flowers in the summer when its dormancy waters are reduced by half; those who have a cooler room without artificial light at night will also be on the upper-hand. The following steps should be performed from autumn through until early spring during a state of inactivity. Keep the roots pot-bound to add further stress onto the specimen, which in turn will significantly heighten the chance of flowering. Blooms will generally appear in the early summer but may occur later in the year in some cases.

N. B. - Be sure to prune the leading growths in the early spring to push the plant into developing flowers, as supposed to more greenery. You can lightly cut off its top growths by an inch with a clean pair of secateurs, removing both the leaves and the portion of the stem where the petioles are housed. 


Sunlight & Location

Be sure to provide a bright location with little to no direct sunlight. Although the winter rays won't necessarily hurt the plant, be careful not to fall in the trap of sun-scorch and severe dehydration.

Place the plant outside in a shaded location during the summer once the nighttime temperatures are above 12℃ (54℉). Not only will this allow the plant to soak up some natural indirect rays, but it'll also increase the chance of bloom in the following spring. Bring the plant back indoors once the summer is over; always check for pests - most notably being Aphids that'll attack the new growth. In order for the Bougainvillea to fully become winterised, avoid the use of artificial lighting at night or locations that boast temperatures higher than 18℃ (64℉) when placed back indoors. 


Hydration

Reduce waters so that at least half of the soil becomes dry. It's essential to keep them on the drier side to life, as they'll think that hard times are ahead and therefore will need to pass its genes on to the next generation.


Occasional Feeds

Whilst in bloom, use a Tomato feed to provide monthly nourishment of potassium; fertilisation isn't needed until the first flower stalk develops from the plant.


Reduce Everything

This is to remind you that everything needs to be reduced - especially the temperature.


Temperature

This is the most significant step; reduce the temperature down by around 5℃ compared to the summertime or place in a room that's between 12º - 15℃ (54º - 59℉). The drop in temperature should ideally last until the inflorescence finishes blooming, although it can still be transferred into the main house as long as it sits on a pebble tray. You'll be at a significant disadvantage if the ambient temperature is kept constant throughout the year, as indoor Bougainvillea will only respond in locations that have daily fluctuations of around 5℃. Never exceed the minimum temperature as it may lead to plant death or yellowed foliage at a bare minimum.




Common Issues with Bougainvillea

Root rot is a common issue among specimens sat in too dark environments with prolonged soil moisture. Symptoms include rapidly yellowing leaves, mouldy soil, stunted growth and a rotten brown base. Take the plant out of the pot and inspect health below the compost line. If the roots sport a yellow tinge, you're good to go, but those that are brown and mushy must be addressed immediately. More information about managing root rot can be found on this link.

Curled leaves and dried brown edges are the result of too little water and over-exposure to the sun. Although Bougainvillea can naturally do well in sun-filled locations, those that haven't acclimatised to the harsh rays will show signs of sun-scorch and environmental shock. Gradually increase the amount of light every few days, starting from an indirect location to a few hours of morning/evening sun over a few weeks. Prolonged exposure will significantly speed the process of dehydration, so consider transplantation into a bigger pot in the spring to wrap the roots around moister soil.

A dark location (shelves, etc.) will promote the vines to develop small or no juvenile leaves, giving the impression of 'leggy' or naked growth. The length between the nodes will also dramatically become larger, harvesting less energy that can be converted into sortable sugars. Be sure to increase the amount of indirect light somewhat, and give the specimen a gentle supplement of 'Houseplant' labelled feed to help with its stored energy. 

Spider Mites are small, near-transparent critters, that'll slowly extract the chlorophyll from of its leaves. Have a check under the leaves, most notably along the midrib, for small webs and gritty yellow bumps. Click here to read our article about the eradicating Spider Mites, along with some extra tips that you may not find elsewhere!

A further pest to look out for is Whitefly. Although these small airborne critters shouldn't produce too much damage, an infestation must be destroyed quickly to reduce the chance of them spreading. Click on the link above to learn more about addressing these issues.

A steady loss of foliage during the autumn & winter, or shortly after flowering, shouldn't cause concern as the specimen is entering its dormancy. Instead of manual pruning its body, allow the plant to drop its leaves naturally to decrease the risk of shock. Puncturing healthy tissue also may result in a bacteria infection in the wound that can quickly spread across the whole plant. Once the shedding of leaves has elapsed, relocate the specimen in a location that offers bright, indirect light and good air circulation. Provide temperatures around 12℃ (54℉) with irregular waters until new growth appears in the spring. One way to decrease the chance of flowering in the first place (that'll result in leaf shedding afterwards) is by keeping the temperature constant throughout the year and above 18℃ (64℉) to reduce the chance of it entering a dormancy.

A lack of flowers in the summer or autumn is caused by an insufficient dormancy period, served in the winter months. Locations that offer near-similar temperatures all year round won't allow the plant to go dormant, resulting in poor spring growth. To achieve, situate in an area that dips to around 10°C (50°F) with fewer waters. Allow the majority of the compost to dry out and provide a humidity tray while the radiators are operating. While we're on the subject, if you'd like to prolong the flowering period, use a fertiliser high in potassium to promote longer-lasting flowers; Streptocarpus or Tomato Food are excellent choices. Other tips to extend this period are to avoid temperature fluctuations and droughts, maintain good humidity and place in a well-lit room with little to no direct sunlight. Read on to find out how to get a Bougainvillea to reflower.

Short-lived flowers could be the product of low humidity or under-watering. Place the specimen on a pebble tray, keeping the reservoir topped up with water while the heaters are operating. Never mist the flowers due to the high risk of developing Botrytis Petal Blight. Keep the soil more on the drier side and introduce a watering schedule to avert the risk of forgetfulness. Wait a month to see if the new changes help the plant's overall health.

Yellowing lower leaves could be the result of over-watering, too little light or nutrient deficiency. Allow the top half of the soil to dry out in between irrigations for the reduced chance of root rot. If the desired location is so dark that you can't even read a newspaper, it'll also be too shady for the plant. The last possibility could be to do with the lack of nutrients in the soil. If you haven't supplemented it in a while, it could be to do with nitrogen deficiency. This element is mobile within the plant, meaning that it can be moved to where the plant needs the most - i.e. the new growth. A lack of nitrogen in the lower leaves will result in the chlorosis, so it's vitally important to keep the soil nutrients topped-up.

A dehydrated plant will result in the majority of the leaves turning yellow, caused by under-watering and/or too much sunlight. Although Bougainvillea need a sufficient amount of the sun per day, too much will result in detrimental issues. A few hours of sun or over five hours of winter sun is the recommended dosage. Try not to exceed these limits as it'll take many months for the plant to bounce back from sun-scorch.





Despite its large popularity in Mediterranean gardens, the Bougainvillea actually originates from South America!



Origins

There are between around twelve species of Bougainvillea that originate from Peru to Brazil. The genus was first described by Philibert Commerçon, a botanist who joined the French Navy admiral, Louis Antoine de Bougainville, on a trip to the Americas in the late 18th century. The most popular indoor species, B. spectabilis, was first described by Carl Ludwig Willdenow, using the Latin word for 'spectacular' that refers to the large show of blooms put out in the spring or summer. 


The Distribution of Bougainvillea spectabilis


Temperature

10° - 25°C   (50° - 78°F)
H1c (Hardiness Zone 11) - Can be grown outdoors between late spring and summer throughout most of the UK while nighttime temperatures are above 8℃  (46℉).  If you decide to bring the plant outdoors, don't allow it to endure more than an hour of direct sunlight a day as it may result in sun-scorch. Regularly keep an eye out for pests, especially when re-introducing back indoors.


Spread

When grown indoors against a trellis, they'll grow up to 3m in height and 3m in width. The ultimate height will take between 4 - 6 years to achieve.


Pruning, Maintenance & Training

Remove yellowed or dying leaves and plant debris to encourage better growth and improve the all-round appearance. Pruning must be done with clean scissors or shears to reduce the chance of bacterial and fungal diseases; remember to make clean incisions as too much damage can shock the plant. Prune leggy spring growth to promote a bushier appearance and remove spent flowers or plant debris to reduce the likelihood of diseases. During the early spring, hard-pruning is advised for bigger, better blooms; be cautious of any early-budded flowers that usually develop in the summer.

At the start of the season, train the loose vines along a trellis that's twice the height of its pot. Once the first set of bracts (think of the tops of Poinsettias), prune the leading growths back to promote a second set. Younger specimens tend to respond better than older plants.


Propagation

Via Seed or Stem Cuttings.

Semi-Ripe Stem Cuttings (Moderate) - This method of propagation is troublesome without the aid of bottom-heat and a controlled environment. Choose the healthiest, most established stems that are wooded, yet still juvenile enough to bend slightly, being just thicker than a phone charger wire. Each cutting should only have a few leaves leaf, above 8cm of semi-wooded stem. Situate the cutting's lower half into moist 'Houseplant' compost; 'Blackleg' can occur when the bottom wound becomes infected, resulting in propagation failure - typically caused by water-logging or serious damage. Maintain bright light and evenly moist soil with the avoidance of direct sunlight or cold draughts. Wrap the pot (& foliage) in a transparent bag or within a miniature greenhouse, and provide bottom heat of temperatures above 18°C (54°F). Remove the bag and place into individual 7cm pots once the second new leaf emerges. Follow the same care routines, as mentioned in the article's top half. This method will take up to five months, so patience and the correct environment are paramount for success!


Flowers

Most Bougainvillea will flower between the months of summer or autumn, lasting several weeks or even months. The flowers are diamond-shaped, laying just above the foliage line to attract airborne pollinators. They have a vanilla-fragrance that can be smelt from metres away.


Repotting

Repot biannually in spring using a 'Cactus & Succulent' labelled potting mix and the next sized pot with adequate drainage. Bougainvillea are far better potbound for several years due to the heightened risk of root rot and repotting-issues (like transplant shock), so only repot if you feel it's wholly necessary - restricted root growth will also increase the chance of blooms, too.

Hydrate the plant 24hrs before the tinkering with the roots to prevent the risk of transplant shock. For those situated in a darker location, introduce an extra amount of perlite and grit into the deeper portion of the pot to downplay over-watering risks. Click on this link for a detailed step-by-step guide on transplantation, or via this link to learn about repotting with root rot.

Book a 1-to-1 video call with Joe Bagley if you'd like a personal guide to repotting your houseplant. This will include recommending the right branded-compost and pot size, followed by a live video call whilst you transplant the specimen for step-by-step guidance and answer any further questions!


Pests & Diseases

Keep an eye out for mealybugs, aphids, spider mites, scale, thrips, fungus gnats, whitefly, blackfly, vine weevils & root mealybugs that'll locate themselves in the cubbyholes and undersides of the leaves, with the exception of the latter two in the soil. Common diseases associated with Bougainvillea are root rot, leaf-spot disease, botrytis, rust, powdery mildew & southern blight - click here to learn more about these issues.


Toxicity

Not known to be poisonous when consumed by pets and humans. If large quantities are eaten, it may result in vomiting, nausea and a loss of appetite. Bougainvillea do have rather sharp thorns on its wooded stems, so always be cautious of children or pets playing nearby. 


Retail Locations

Some florists & Online Stores. Specimens are likely to be found in summer outside at most garden centres; it's not advised to bring outdoor specimens inside as this could lead to environmental shock and introducing foreign pests into the home. Search around for indoor specimens online. 



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