How to grow Cosmos flowers from Seed

Growing Cosmos flowers From seed is actually an easy process, these frothy flamboyant flowers require minimal effort for maximum impact. Wonderful flowers for homegrown bouquets, the more you cut the more they grow!

Cosmos Bouquet
Double Click Cosmos

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Cosmos Flower Origins

Cosmos is an English Garden Favourite, lovingly grown by English Gardeners for generations, but it is not native to British Lands. Its origins begin in Mexico and South America and became a Favourite of Spanish Priests in the 16th Century, whom grew the Sun Loving flowers in their Mission Gardens. The priests are credited with naming the flowers ‘Cosmos’ due to their evenly spaced petals. ‘Cosmos’ in Greek means harmony or, ordered universe. It wasn’t until the late 18th century, the pretty blooms made their way to England and soon became an English Garden Staple.

Cosmos flowers Characteristics

This Popular low-maintenance flower is a showy annual that typically grows 2-4 ft tall on erect frothy foliage covered stems. They typically have large bold Daisy like flowers and are a Favourite of Bees and Butterfly’s. Cosmos bloom colours are typically Pinks, Purples, Red, Orange, Yellow, and White.

cosmos flowers
Cosmos Sensation

Cosmos Flowers Symbolism

Cosmos flowers represent Balance, Tranquillity, Joy, Modesty, Innocence, Peace, Love and Beauty. The orderly arrangement of the flowers is a visual of the balance required in order to achieve all those elements.

Cosmos Symbolism based on Colour

  • Pink- Pink cosmos represent the gentleness of love such as kisses and warm hugs. Pink often associated with femininity and the innocent nature of the colour is also representative of a pure love, such as ‘a mothers love’. A gift of Pink Cosmos to a Child is a gesture of the purist kind of love, from mother to child.
  • Red- Love and Passion
  • White- Faithfulness and devotion, a romantic gesture between partners
  • Yellow- Representative of friendship. Gift a bunch of Yellow Cosmos to a friend and let them know your thinking of them

How to Grow Cosmos Flowers from Seed

how to grow cosmos
Cosmos Sensation

It couldn’t be easier to grow this cottage garden favourite, their undeniable charm and beauty is represented by the many English gardeners that choose to grow the showy flowers year after year in their gardens. Romantic, frothy blooms that sway in the breeze and attract pollinators in their droves. Here’s how I grow Mine…

Buy Cosmos Seeds Here

Here are the varieties I grow each year

Double Click Pink Rose BonBon

Cosmos Sensation Mixed

How to Sow Cosmos Seeds Indoors

Sow Cosmos seeds in modules 1/2 cm deep From March to April. Water and place on a warm Windowsill and cover with a propagator lid or cling wrap until seedlings emerge. Cosmos seeds can take from 7-21 days to germinate. Harden Off the plants and Plant out after the last frosts for your region, for me ( Lancashire) this is generally around mid May.

how to grow cosmos
Cosmos Seedlings

How to Sow Cosmos Seeds Outdoors

Sow Cosmos seeds directly into the bed you wish them to flower. This is best done when the soil has warmed up in the UK, around May Onwards. Sow thinly then thin out your Cosmos seedlings when they are well developed to avoid overcrowding. Choose a Sunny Spot to sow your Cosmos, these blooms love the sunshine!

cosmos bed seedlings
Cosmos Seedlings late May

What Does Hardening Off Mean?
Plants raised indoors or in a greenhouse environment, need to be acclimatised to cooler temperatures and increased air movement for about two to three weeks before they are planted outdoors permanently . This is a ‘toughening up’ practice to prepare the plants for their new environment.

How to Harden Off
Place your plants out for a couple of hours in a shady part of the garden. The next day, leave them out again for two hours, but this time allow the plants an hour of direct sunshine in the morning. Gradually continue to increase the length of time the plants are in direct sunshine over the course of roughly two weeks.

Pink cosmos

Where to Grow Cosmos

Cosmos Seedlings transplant well so you could grow them in large pots as well as beds, Cosmos will thrive in either environment. Place Cosmos at the back of a bed or give them their own bed like I have.

how to grow cosmos

Common Cosmos Pest Problems

Cosmos plants are vulnerable to slugs and snails, particularly when the plants are young and tender. A hungry slug can easily demolish a Cosmos plant in record time. The way I deal with this is by removing by hand any slugs and snails I see and using beer traps . A few will always get by me, but for the most part my Cosmos are unaffected.

How to Take Care Of Cosmos

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Tall Cosmos Varieties, such as Double Click and Sensation will require a support of some kind. I simply push some bamboo sticks into the bed perimeter and string some twine to stop the Cosmos from falling over. Cosmos takes around 12 weeks from seed to blooms. To keep them looking healthy, keep on top of the deadheading and remove any spent flower heads to encourage new growth.

how to deadhead cosmos

Cosmos Cut Flowers

The plant that keeps on giving! The more you cut the more they grow, giving gorgeous blooms well into Autumn, Cosmos flowers will last for 7-10 days in a vase.

Growing Flowers

Want to learn how to grow your own flowers from Seed? Have a nosy at these ‘How to’ posts…

How To Grow Sweet Pea from Seed

How to Grow Lupins From Seed

How to Grow Foxgloves from Seed

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