Sowed Cosmos Seeds March, September No Flowers

Question

These plants are 5-6 foot tall, stems thicker than your thumb. Very strong and healthy. 6 months later, still no sign of a single flower. Good fallow earth, added T&M flower food July & Aug.

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Answer 1

It sounds like a problem with nutrient ratios. Too much nitrogen and not enough phosphorus and potassium can cause these symptoms. In general, the soil could be too rich in nutrients. These flowers cannot handle fertile soils.

Test your soil for deficiencies, overloads, or pH swings and correct as needed. Here are some articles that will help:

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm

This article will help you to grow the flowers:

https://www.gardeningknowhow.com/ornamental/flowers/cosmos/growing-cosmos.htm