Cosmos bipinnatus
Encyclopedia
Cosmos bipinnatus, commonly called the garden cosmos or Mexican aster, is a medium sized flowering herbaceous plant
native to Mexico
. The species and its varieties and cultivars are popular as an ornamental plant
in temperate climate gardens. It can also be found in natural areas in much of North America, where it is a "garden escapee"-introduced species
and in some habitats becoming a pest weed.
, although plants may re-appear via self-sowing for several years. The plant height varies from two to four feet. The cultivated varieties appear in shades of pink and purple as well as white. Its foliage is finely cut into threadlike segments. When flowering, the plant can become top heavy. This problem is alleviated when grown in groups, as the bi-pinnate leaves interlock, and the colony supports itself.
Excessive rain can cause cultivation problems, due to the delicate nature of the stems. Heavy rain can cause breakage. The Cosmos bipinnatus can tolerate heat as long as adequate moisture is provided, however, it does not handle droughts, strong winds or cold temperatures well. Snails, slugs and aphids have a taste for the Cosmos bipinnatus. Successfully cultivated plants can mature 2 to 4 feet x 12 to 18 inches.
and pollinators-honey bee habitat gardens.
Herbaceous plant
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
native to Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. The species and its varieties and cultivars are popular as an ornamental plant
Ornamental plant
Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as house plants, for cut flowers and specimen display...
in temperate climate gardens. It can also be found in natural areas in much of North America, where it is a "garden escapee"-introduced species
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
and in some habitats becoming a pest weed.
Description
Cosmos bipinnatus is considered a half-hardy annualAnnual plant
An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...
, although plants may re-appear via self-sowing for several years. The plant height varies from two to four feet. The cultivated varieties appear in shades of pink and purple as well as white. Its foliage is finely cut into threadlike segments. When flowering, the plant can become top heavy. This problem is alleviated when grown in groups, as the bi-pinnate leaves interlock, and the colony supports itself.
Varieties
Some of the varieties of Cosmos bipinnatus in cultivation today include:- Sensation, also known as Early Sensation, is a widely available mix of tall varieties
- Versailles and Sonata, developed for the cut flower trade, are shorter than the species, with heights remaining below three feet
- Daydream features a pink inner ring on a white background
- Seashells features quilled petals
Cultivation
Growth characteristics of this plant include:- GerminationGerminationGermination is the process in which a plant or fungus emerges from a seed or spore, respectively, and begins growth. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. However the growth of a sporeling from a spore, for example the...
takes between 7 and 10 days at the optimal temperature of 75 degrees Fahrenheit (24 °C); flowering begins between 60 and 90 days after germination - It prefers a soil pHPHIn chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
between 6.0 and 8.5, reflecting its native habitat in the alkaline regions of Central AmericaCentral AmericaCentral America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent... - Flowering is best in full sun, although partial shade is tolerated
Excessive rain can cause cultivation problems, due to the delicate nature of the stems. Heavy rain can cause breakage. The Cosmos bipinnatus can tolerate heat as long as adequate moisture is provided, however, it does not handle droughts, strong winds or cold temperatures well. Snails, slugs and aphids have a taste for the Cosmos bipinnatus. Successfully cultivated plants can mature 2 to 4 feet x 12 to 18 inches.
Pollinators
The flowers of Cosmos bipinnatus attract birds and butterflies, including the Monarch butterfly. It can be part of butterfly gardeningButterfly gardening
Butterfly gardening is a growing school of gardening, specifically wildlife gardening, that is aimed at creating an environment that attracts butterflies, as well as certain moths, such as those in the Hemaris genus. Butterfly gardening is often aimed at inviting those butterflies and moths to lay...
and pollinators-honey bee habitat gardens.
External links
- Jepson Manual Treatment - Cosmos bipinnatus
- USDA Plants Profile
- Cosmos bipinnatus - Photo gallery