Garden cosmos

A very cute annual - and an easy one to grow : just sow, water a bit, forget all about it till it blooms, and enjoy!
Common name : Garden cosmos
Scientific name : Cosmos bipinnatus
Family : Asteraceae
Category : Annual
Minimal water
Minimal water
Flowery
Flowery
Cosmos bipinnatus - the garden cosmos or Mexican aster - is a medium-sized flowering herbaceous plant native to Mexico, and popular as an ornamental plant in temperate climate. It is a half-hardy annual, although plants may reappear via self-sowing for several years. The cultivars (cultivated varieties) appear in many colors and shades of pink and purple as well as white. Beware : as it spreads quite easily, it is considered a weed in some parts of the United States.

Sowing & planting

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Flowering

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Caracteristics

Exposition
Water needs
Granulométrie plants.granulometry_3
Frost-resistance Medium
Zone USDA 9a
Height 20 - 120
pH 6 - 7

Identify my garden cosmos

The cosmos are annuals native from Mexico. Their height varies between 35 and 120 centimeters, depending on the variety. The flowering period goes from early summer to autumn frosts, they are resiliant to light frost, and they are usually used in clumps, borders, in bins or in rock gardens.

Sow my garden cosmos

From the middle of March for mild climates and from April in the more northern regions, choose a sunny place - not scorching - for your cosmos: without sun, the cosmos do not bloom well. As for asters, an ordinary garden soil mixed with potting soil is ideal. Avoid soils that are too heavy and too compact that keep moisture to the detriment of the cosmos. To make a beautiful groundcover, plan a dozen feet per square meter. You can totally sow cosmos in bins - rather in large containers than in small pots.

Thin out my garden cosmos

Once seedlings have emerged, you can thin out your young plants. This consists in removing the most fragile and too crowded plants. Keep a dozen plants per square meter - well distributed!

Mulch my garden cosmos

You can mulch between the plants one to two weeks after planting with the aid of a mulch which holds in moisture. This will limit evaporation from the soil, and thus the need to water and to weed.

Remove my garden cosmos

Cosmos can't withstand freezing, then only one solution: you will need to sow again next year! In the meantime, after flowering, clean the plots to accommodate new plants, gently pulling the stems that should come gently, including roots - or use a spade if it resists!

Water my garden cosmos

Water seedlings in fine mist, maintaining the soil always moist - if in a pot make sure you use drainage pots. After a few weeks, watering once a week should be fine.

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