Madagascar Periwinkle: Improper Watering Can Lead to Various Diseases
Annual vinca ( Catharanthus roseus ) , which is also known as Madagascar periwinkle , is a common , easy - to - grow annual bedding flora that is wintertime intrepid in USDA zones 10 to 11 .
Like all plants , genus Vinca need some degree of wet to flourish ; however , too much body of water can be prejudicial to this coinage . In fact , annual vincas are so sensitive to water that they are considered short - lived annual because they often succumb to a issue of diseases have by excess moisture .
Types of Vinca
Species vinca plants are not common in cultivation , concord to theMissouri Botanical Garden . However , there are many cultivars on the market in various shades of pink as well as red , livid and lilac .
There are standard - size and dwarf choice available . Vincas can be grown in containers , and there are trailing vincas for hanging baskets .
one-year genus Vinca are distinct from perennial genus Vinca ( Vincaspp . ) , also known as periwinkle , which are ground top plants that spread quickly and therefore have a tendency to become invasive .
Watering Annual Vinca Flowers
Annual genus Vinca plants do not need a lot of body of water . * * They should ideally meet about an inch of water a calendar week from rainfall . * *
During dry spells , you ’ll want to irrigate profoundly once or twice a week . Vinca plants are drouth tolerant once established , so you desire to be careful not to overwater them .
skillful drain is also essential for genus Vinca industrial plant . To elevate salutary drain , it is a safe thought to remediate soil with organic matter prior to planting vincas . This is especially important in labored clay soils .
Tip
Vinca industrial plant should ideally get about 1 inch of water system a week from rainfall , but you ’ll need to water deep once or twice a hebdomad during dry go . Just ensure your soil drains well and is amended with organic matter prior to planting .
Avoiding Vinca Diseases
Thoughtful lachrymation and monitoring of weather condition is cardinal to prevent and deal disease that can untimely obliterate one-year vinca plants .
Stem and Root Rot
Vinca plants are very susceptible to root and root rot because of the pathogenPhytophthora nicotianae . This disease is typically because of extravagant irrigation . Root rot can also come during period of time of intense rain .
symptom of beginning decompose in vinca plants include chlorosis , or the yellowing of leaves . plant become stunt before they wilt and choke . Stem molder manifests as dark lesions , with die back occur above the affected orbit .
Vinca plants suffering from theme and root rot should be destroyed . In this case , you’re able to also apply fungicides to remaining plants to prevent the disease from spread .
Leaf Spots
When watering vincas , you want to focus body of water on the root and avoid overhead watering . This is because moisture on the foliage can lead to fungous leaf spot that can diminish the coming into court of the plant . As the spots produce and proliferate , leaves turn white-livered and drop off .
TheClemson Cooperative Extensionalso recommends watering vinca plants before dawn to give the leaves copious time to dry during the daytime . Spraying vinca plants weekly with a antifungal known as chlorothalonil can also help control the kingdom Fungi that make leaf spots .
Gray Mold
gray-headed mold is another annual genus Vinca disease that can be make by overhead lachrymation . This fungous disease can lead in leaf spots , root word cankers and root rots . It is uncouth in spring during humid weather condition .
The fungicide thiophanate methyl radical can be applied in times of supernumerary precipitation , which is one of the weather condition that encourages the development of this disease .
