Cosmos Cosmos bipinnatus 'Lemonade'

Water

Cosmos, commonly known as Garden Cosmos or Mexican Aster, should be watered deeply but infrequently to encourage strong root development. Aim to water once a week, providing about 1 gallon of water per plant, which allows the moisture to penetrate deeply into the soil. During particularly hot or dry periods, increase the frequency to twice a week. Always check the top inch of soil for dryness before watering; if it is dry, it's time to water your Cosmos. Overwatering or allowing the plants to sit in water can lead to root rot, so ensure good drainage and allow the soil to dry between waterings.

Light

For Garden Cosmos or Mexican Aster, full sun is ideal, meaning at least 6 to8 hours of direct sunlight per day. Place your plants in a location that receives unfiltered sunlight for the greater part of the day. These flowers thrive in bright conditions and may become leggy or produce fewer blooms in partial shade. The best spot is an area with clear exposure to the sky, away from taller plants or structures that could cast shade.

Temperature

Cosmos, or Garden Cosmos, thrive in a wide range of temperatures, with ideal growing conditions being between 60°F and 90°F. They can survive minimum temperatures down to about 25°F, but frost can damage the plants or kill them. Maximum temperatures should not exceed 100°F as extreme heat can stress the plants. Ensure your Cosmos are planted in a site where they can receive adequate sunlight without overheating in excessively high temperatures.

Pruning

Pruning Garden Cosmos or Mexican Aster is generally done to maintain shape, encourage bushier growth, and promote more blooms. Deadhead spent flowers regularly to extend blooming and cut back any leggy stems during the growing season. Prune Cosmos by pinching or cutting the stems just above a leaf node. The best time to prune is in the late spring or early summer, but light, ongoing pruning can be done throughout the blooming period.

Cleaning

As needed

Soil

The best soil mix for Cosmos, commonly known as Garden Cosmos, is well-draining, nutrient-rich, with a pH between 6.0 and 7.0. A combination of loamy soil, peat, compost, and perlite or vermiculite would provide suitable conditions for robust growth. Regular fertilization isn't necessary as Cosmos thrives in moderate fertility.

Repotting

Garden Cosmos typically does not require frequent repotting as it is often grown as an annual. However, if grown as a perennial or in containers, repot every 2 to 3 years to refresh soil and accommodate root growth.

Humidity & Misting

Cosmos, or Garden Cosmos, prefer moderate ambient humidity but are quite adaptable and can thrive in average humidity conditions typical of most outdoor environments. Avoid overly humid conditions as this can promote fungal diseases.

Suitable locations

• Indoor

  Place Garden Cosmos in bright light indoors, keep the soil moderately moist.

• Outdoor

  Plant Cosmos in sunny spots with well-drained soils.

• Hardiness zone

  2-11 USDA.

Life cycle

'Lemonade' Cosmos, a variety of Cosmos bipinnatus, starts its life cycle when the seeds are sown into warm, moist soil in spring after the last frost. The seeds germinate within 7-10 days, developing into seedlings with true leaves beside the initial cotyledons. As they mature, these plants grow into upright, branching stems with fine, feathery foliage and eventually produce their distinctive lemon-yellow flowers, typically starting in summer and continuing into fall. During their blooming period, they attract pollinators such as bees and butterflies which facilitate the cross-pollination necessary for seed set. After pollination, the flowers develop into seed heads that mature and, upon drying, release seeds that can disperses to begin new plants. The 'Lemonade' Cosmos is an annual, so it completes its life cycle within one growing season and dies with the first hard freeze, relying on its seeds to propagate the next generation.

Propogation

• Propogation time

  Spring to early summer

• Cosmos, commonly referred to as Cosmos bipinnatus 'Lemonade', can be propagated most effectively through seed. The ideal time to start seed propagation is in late winter to early spring, around 4-6 weeks prior to the last frost date when soil temperatures are around 75°F (24°C). Seeds should be sown shallowly, approximately 1/8 inch deep, in well-draining soil mix and kept moist until germination, which typically occurs within 7-10 days. Once the seedlings develop their first set of true leaves, they can be thinned out or transplanted to individual pots before being moved outdoors after the risk of frost has passed. Planting seeds directly in the garden can be done after all danger of frost is over, and the soil has warmed up. This straightforward method allows the cosmos plants to grow quickly, eventually blooming in the summer and lasting until the fall.