String of Dolphins - Dendrophorbium Peregrinum

Dendrophorbium peregrinum. (Previously known as 'Senecio peregrinus')

Contents

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

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Top Tips & Info

• Care Difficulty - Easy
• A location that promotes a good level of light penetrating the soil's surface is mandatory for the prevention of rotten foliage. We'd recommend a splash of either early morning or late evening sunlight to help the overall health of the specimen. 
• Less is more with String of Dolphins; allow all of the soil to dry between hydration, reducing this further in the autumn and winter. If you're stuck with when to water it, think of the ukhouseplants' phrase of 'drenches between droughts'.
• Be mindful when watering, avoiding excess moisture to sit on the leaves above the soil to prevent rot. Either be careful when watering or irrigate using the bottom-up method to avoid such a catastrophe.
• Fertilise every two or three months using either a 'Cactus' or 'Houseplant' labelled feed. 
• Repot every three years during the spring, using a 'Cactus & Succulent' potting mix and the next sized pot. Be careful of breaking its delicate vines, but equally, can be propagated if separated from the plant.

Location & Light - 🔸🔸🔸

Provide a bright, indirect setting away from more than two hours of direct light. We'd recommend situating yours in either a north, east or west-facing window, or somewhere that boasts overhead lighting. Avoid shady locations or shelves if possible, as the lack of light hitting the soil's surface will increase the risk of basal rot and leggy internodes. If you're worried about its location being too dark, if a newspaper can be read while having your back towards the window, you're good to go.

Water - 🔸

Allow all of the soil to dry out in between waters, ensuring that the pot feels very light before another hydration. Although pouring water directly through the foliage is acceptable if situated in a sunny location, irrigate using the bottom-up method to be extra sure. Place the pot on a saucer of water (25% submerged) until thorough absorption to provide deep hydration. Wetting the foliage every time you come to hydrate the plant will allow excess moisture to settle, causing the leaves to yellow and rot away. Over-watering symptoms include rapidly yellowing or shrivelling leaves, mushy foliage and eventual plant death; scroll down to 'Common Issues' for more information. Under-watering symptoms include deflated leaves, little to no growth and gradual foliage decline. Be sure to study its environment; a position that offers too much sunlight will dry out the soil far too quickly and will eventually scorch the plant's leaves; move to a darker location.

Humidity -

This isn't a factor; however, a quick hose-down once a month will help with hydration of leaves, but will also help wash off excess dust and possible pests.

Fertilisation - 🔸

Fertilise every two months during the growing period and every three months in the autumn & winter to replicate its dormancy period. Although a 'Houseplant' fertiliser will still do the job, we'd recommend using a specific 'Cactus' labelled feed as it'll support the vital thirteen nutrients that this species will need to grow.

Common Issues with String of Dolphins

A lack of leaves on the soil's top could be the product of excess moisture settling on the foliage. Although watering from the top is best, it's recommended to use the bottom-up method if you're a messy waterer. For specimens that have a bare head, improve growing conditions by using this method and increasing the light levels and air circulation. Take vine cuttings to promote a bushier appearance above the soil line - scroll down to 'Propagation' for more information. Finally, always remove yellowed or rotten debris from the soil as it could harbour both bacterial and fungal diseases, which will continue the plant's decline.

Root rot is a common problem among specimens sat in too dark environments with prolonged soil moisture. Symptoms include rapidly wilting 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 or scroll down to the last image to see a healthy root system example.

Failed vine cuttings are a problem among gardeners, with damaged wounds or too small vines being the usual culprits. Although propagating String of Dolphins is relatively easy, people still find it hard to ace. Scroll down to 'Propagation' for more information.

Reddened leaves are the product of too much sunlight, most common during the height of summer. A pigmentation called 'Carotenoids' will alter the appearance of the foliage to counteract the harsh effects of the UV rays. Although this isn't a permanent look, and the specimen will still function adequately, it'll grow far better and quicker in a slightly shadier location with only a splash of direct sun. Still providing an hour or so of bright light will lessen the effect of environmental shock and potential death.

Alternatively, a dark location (shelves, etc.) may 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 'Cactus & Succulent' labelled feed to help with its stored energy. 

Origins

This species was first documented by August Grisebach in 1879 as Senecio peregrinus, using the Latin word for 'dolphin' for its appearance. During the early 1990s, Charles Jeffrey revised the species into the genus of Dendrophorbium, after several morphological tests and studies. Although many believe it's actually a cultivar between the S. rowleyanus and S. articulatus, the Royal Botanical Gardens of Kew states its authenticity as a naturally-occurring species in South America.

The Distribution of Dendrophorbium peregrinum.

Temperature

15° - 26°C   (59° - 78°F)
H1a (Hardiness Zone 13) - Must be grown indoors or under glass all year round. Never allow temperatures to dip below 15℃  (59℉)  or permanent damage may occur in the likes of flower loss, stunted growth and blackened or yellowed leaves.

Spread

Up to 80cm in length with its width solely relying on diameter of the pot that it's in. The ultimate height will take between 3 - 5 years to achieve, but can live over twenty years or more in the right care.

Pruning & Maintenance

Remove yellow or dying leaves, and plant debris to encourage better-growing conditions. While pruning, always use clean utensils or shears to reduce the chance of bacterial and fungal diseases. Never cut through yellowed tissue as this may cause further damage in the likes of diseases or bacterial infections. Remember to make clean incisions as too-damaged wounds may shock the plant, causing weakened growth and a decline in health.

Propagation

Vine Cuttings (Moderate) - Choose the healthiest stems located at the vine terminals; these should be damage-free and wholly plump. Cut off at least five inches and remove the older half of the leaves for the reduction of transpiration (moisture loss). Use a well-draining potting mix, preferably 'Cactus & Succulent' compost, and coil the vine in a circular shape, pinning it down with a paper clip. Cover the older half in half an inch of soil (the area where you removed the leaves) to promote quicker root development. Try not to cover the actual foliage with soil as this will harm its light-capturing efficiency, along with higher rates of rotting. Place the potted cuttings into a transparent bag and mist the soil and foliage once a week to maintain high humidity. Situate it in a bright, indirect setting with temperatures above 18°C (64°F). Be sure to pierce a few holes in the bag and actively remove any yellow or rotten debris to present a healthier environment. As the roots will develop first, remove the bag and treat it as an adult specimen once there are signs of new foliar development.

Flowers

Small clusters of white flowers will develop along the vine during spring to early summer, once the plant has matured. The quality of its blooms largely relies on the quality of the dormancy period served in the previous autumn and winter. To replicate its dormancy period:

1. Reduce temperatures down to around 15°C  (59°F)  from late autumn until early spring, with little watering.
2. Allow all of the soil to dry out for around a fortnight in between irrigation thoroughly.
3. Provide a few hours of off-peak direct sunlight with little fertilisation throughout this period to ensure a good dormancy. 

Repotting 

Repot every three years in the spring, using a 'Cactus & Succulent' labelled potting mix and the next sized pot with adequate drainage. String of Dolphins 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 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!

Although this is a String of Bananas, its root system is almost identical to the String of Dolphins. A healthy root system should be cream/light brown coloured and solid when pinched. If you find any rot, prune away the affected roots and repot back into the same sized pot with 'Cactus & Succulent' soil; never over-pot a this plant if the root system is unhealthy. 

Pests & Diseases

Keep an eye out for mealybugs, aphids, scale, whitefly, blackfly & root mealybugs that'll locate themselves in the cubbyholes and undersides of the leaves, except for the latter in soil. Common diseases associated with String of Dolphins are root rot, botrytis & southern blight - click here to learn more about these issues.

Toxicity

This plant is classified as poisonous, so if small sections are eaten, vomiting, nausea, and a loss of appetite may occur. Consumption of large quantities must be dealt with quickly; acquire medical assistance for further information.

Retail Locations

Online Stores.

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