Plant Care
Mandevillas
Among the prettiest of the summer-flowering vines are the South American mandevillas, many of which are known as dipladenias. They have some of the most beautiful flowers in the garden and they bloom prolifically during the warmer months.
1. Choosing a Mandevilla
Mandevillas fall into three loose groups:
Large-flowered mandevillas – These all have large flower trumpets that are set against deep green, occasionally pleated, leaves. There are many cultivars available.
Deciduous mandevilla (Mandevilla laxa) loses its leaves in winter, but makes up for this bare period by producing waves of fragrant summer flowers. This is the best mandevilla for colder districts. It’s said to tolerate down to -6 degrees and, even if cut back completely by the cold, it will re-shoot from the base. Mandevilla laxa’s perfume is particularly attractive at night.
Dipladenias – This is one of those curious cases where a plant’s common name ‘dipladenia’is more complicated than its botanical name, but don’t let this put you off growing what are some of the best container plants. Dipladenias are considered to be forms of Mandevilla sanderii. Their smooth, shiny leaves start off with a light yellow-green colouration that gradually ages to deep green.
2. Caring for Mandevillas
All mandevillas need good drainage – overwatering causes many failures. The tuber- like roots, which are very efficient at holding water, are likely to rot if they remain wet for any length of time.
If soil is heavy and drainage is doubtful it’s safest to grow mandevillas in large pots. A 400mm or 500mm Yates Tuscan pot makes a good choice because these containers have plenty of drainage holes.
Use a quality potting mix (like Thrive Premium). Mulch with a light organic mulch (keeping it well clear of the trunk) and feed with Dynamic Lifter pellets or Thrive Once- A-Year Feeder. In colder areas potted mandevillas can be moved inside as winter approaches. They make good indoor plants if they’re placed near a well-lit window.
3. Pests and diseases
Watch out for aphids clustering on the new shoots in spring and summer. Pinch them off or squirt with Yates Bug Gun or Nature’s Way Insect Spray. The latter will also take care of the minute red spider mite that can infest the leaves when the plants are in dry situations. Scale insects can also be troublesome but these are easily wiped off with a cloth dampened with a little Conqueror Oil or, for more severe infestations, with an application of Confidor. Yates Rose Gun will take care of most insect pests, as well as the powdery mildew fungus that can attack the leaves.
Comments (8)
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steve
Yates site member
03:27, 23 September 2009
I planted red mandevillas outside in large planters. They have done very well - constantly pushing out new flowers on their vines. Question - how to move them safely indoors?
Julie
Yates site member
15:59, 13 October 2009
My red mandevilla's leaves are curled up & now the flowers are curling too...how do I fix this?????
Toni
Yates site member
12:27, 25 January 2010
I have a lovely mandevilla but it is only a shrub - it has no "fingers" to climb up with... What do I need to do to make it a climber? or is it just a different variety? Regards Toni Peters
Kate
Yates site member
16:04, 13 April 2010
I have 3 mandevillas in a pot with good drainage and now the leaves are turning yellow and falling off... what is causing this? Help before they die altogether!!
lois
Yates site member
11:38, 19 April 2010
my mandavilla has yellowing leaves
lois
Yates site member
11:40, 19 April 2010
ive got no comment
lois
Yates site member
11:41, 19 April 2010
no comment
lois
Yates site member
11:43, 19 April 2010
what am i doing wrong
liv
Yates site member
21:36, 27 April 2010
Hi Kate and Lois. The mandevilla leaves are supposed to turn yellow and die off at this time of year in Australia. They are semi deciduous so most but not all the leaves will drop from now though winter and replenish in spring when the fresh new growth comes. I usually push them off once they yellow as they look unsightly. They will usually stop flowering over winter too! Hope this helps.
Megan
Yates site member
09:45, 22 May 2010
Could also be a fungal problem called anthracnose which is common in mandevillas if high rainfall or overwatering/ high humidity. If the leaves have brown blemishes on them prior to yellowing and falling it is almost likely to be fungal. Treat with copper oxychloride spray.
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