Sonata White Cosmos Seedling Plants

Cosmos Sonata White

At between 40-60 cms tall Cosmos Sonata White is much smaller and tidier than your average Cosmos bipinnatus, which can often reach 100 cms. This plant is the classic white of the Sonata range which is made up of dwarf Cosmos that were developed for smaller gardens, window boxes and container gardening in general. It is certainly the "go to" white Cosmos for a limited space. If you have pots to fill, try some! Browse our ready to plant cosmos seedlings. 

Planted in a drift, by itself or mixed with other colours in the range, Cosmos Sonata White can put on a breath-taking display. Annual Cosmos produce staggering quantities of very "cuttable" flowers In a seemingly endless stream (flood more like) from May until November. Because it is a smaller plant than Cosmos such as the Double Clicks, the stems will be somewhat shorter than those of its taller cousins but, although we have not counted, it seems to produce about as many flowers.

Cosmos Sonata White Features:

• Half-hardy Annual
• Colour: Pure white with gold stamens
• Height: 45-50 cms
• Planting Months: April - June/July
• Flowering: May - November
• Plant Spacing: 25-30 cms

Plant Cosmos Sonata White seedlings in well prepared, moist soil that ideally was enriched with a little organic matter the previous autumn. Not too much as Cosmos flower better if the soil is not overly rich. Water well after planting and for at least a week after that just to make sure they establish well.

The Sonata series of Cosmos are ideal for growing in containers as none of them reach more than 50 cms tall. However they are bushy plants, and so need enough compost in the pot to stop a strong wind blowing them over so we would suggest using pot sizes of at least 5 Litres and preferably a bit more. Any general purpose compost will do here.

The main requirements are that your plants have enough light and water - they grow very fast and flower hugely through summer so moisture is important. They can cope with a little shade but flower better in full sun. As a guide, they need a bare minimum of 4 hours direct light a day, but they do better with more.

Because you are buying seedlings, you can plant your cosmos into their final flowering positions immediately. Space your plants 20-25 cms apart and (in a bed) plant them in drifts of 12-15 plants. They will either need a 60 cms cane per plant (which should be pushed in about 25 cms deep and about 5 cm from a plant) or a support made of twine or pea/bean netting. This should be stretched between canes about 20-30 cms above ground level and the cosmos can then grow through it. It is not pretty at first but the plants disguise it very quickly and it is an effective solution. Just don't plant a group that is so big you can't reach the middle...

As flowers develop cut them or dead head when they are over and your cosmos will carry on flowering all summer long. Well grown Cosmos can quite literally produce a hundred flowers or so per plant in a season.

To maintain flower quality and size, you can use a high potash and phosphate fertiliser every fortnight throughout summer. Home-made comfrey tea is perfect or one of the specialised tomato fertilisers will do very well.