why is my cosmos flower not blooming?

Why is my cosmos flower not blooming is one of the most asked questions by gardeners. Cosmos plant has attractive and eye-catching color flowers that intensify the beauty of a garden.

Most people around the world use it for ornamental purposes. The plants have fascinating flowers as well as graceful leaves. Sometime cosmos does not bloom properly. Blooming is the process of producing flowers when the plant is mature enough and ready to reproduce.

But most of the time gardeners face problems with flowers blooming. several reasons may be related to this problem. let’s discuss all of them one by one. I hope you will find out why your cosmos flower is not blooming!

Reasons For Cosmos Plants Not Blooming

There are various reasons related to such conditions of plants because flowering is a complicated process.

It is controlled by a number of factors such as the duration of sunlight and its quality, hormone level in plants, watering, and quantity of nutrients. It is mostly related to using of fertilizers as well.

1. Sunlight Duration

Cosmos plants require full exposure to sunlight for at least 6-8 hours a day. But during hot months of the year, it must be protected from the midday sun.

When the plants do not receive such a duration of sunlight they will not bloom properly. Sunlight and plant hormones work together for flower production.

If the plants receive sunlight and have a duration greater or less than 6-8 hours they will show abnormality in their blooming pattern.

2. Water Requirement

During the early growing days of cosmos plants, the soil must constantly be moist but later when the cosmos plant is mature enough, it requires an inch of water per week. But it must be noted that the soil is not waterlogged.

Water logging as well drought condition both affects badly the flower blooming. The best way to check water quantity in the soil is to put your finger in water about an inch below. If it does not feel wet enough then it’s time to water your plant.

You can also use a moisture meter or some other device available in the market to measure the quantity of water in the soil.

3. Nutrient Deficiency

Every process inside a living organism needs nutrients. For plants to bloom it requires a number of nutrients. Among them, phosphorus(P) is the most important. So if your plant is not blooming check for phosphorous quantity in the soil.

It is possible to test nutrient content in soil at home without taking help from any expert or laboratory. Soil testing kits or soil testing strips are available online or you can easily purchase them in garden centers. This will allow you to test the P content in soil at home by yourself.

So if you find out that phosphorus quantity is present in very less amount then add fertilizers that have phosphorus in them. Soil testing is also necessary because most of the time we have tons of nitrogen in the soil and no phosphorus and other nutrients.

So it is really necessary to carry out soil nutrient tests.

4. Over Fertilization

Most people are unaware of the proper use of fertilizers. They add fertilizers to the soil without any limit and this causes a lot of damage to the soil as well as to plants.

One such damage is to bloom. A high quantity of fertilizers in the soil causes an imbalance among nutrients and ultimately affects blooming.

For adding fertilizers timing is the most important. A cosmos is an annual plant so add fertilizers at the beginning of the growing season for blooming. Try to avoid fertilizers when the plants are blooming.

5. Pest and Diseases

If all of above mention reasons are not present and still your plant is not blooming then check your plants properly for pests and other diseases. These may affect the most important parts of plants such as leaves and flowers.

Pests such as aphids, trips, or spiders cause many abnormalities such as abnormal or improper development of flowers. If these pests attack your plant after flower development then it can also cause them to fall off.Use any effective insecticides when you notice any such insects on your plant body.

Diseases such as leaf spots and powdery mildew can affect the flowering of plants. This can be prevented by using any fungicides that prevent the spread of disease.

6. Mechanical Injury To Plants

Many times different parts of plants are mechanically injured. Such injuries to important plant parts such as roots will affect overall plant health. Roots take up water and nutrients from the soil and any injury will affect cosmos plant blooming.

7. Improper Pruning

Improper pruning can affect plants in many ways. Pruning at the wrong time or the wrong way can cause lots of trouble. One such effect is the blooming of plants.

if you prune your plant too heavily it may possibly remove new plants and ultimately the number of flowers will be reduced. so it is really important to learn proper pruning techniques before taking any action.

8. Deficiency Of Hormone

Flowering requires plant hormone florigen. But it is not available in synthetic form. Its deficiency cause abnormalities in blooming. Apply the hormone gibberellic acid to the plant to promote blooming. It is easily available at any gardening stores and online retailers.

However, use it after following all safety measures as it causes toxicity in an excessive amount. It is best to consult a professional before use.

Improving Cosmos Plant Blooming Summary

In conclusion, if you want to bloom your cosmos plant try to follow the following guideline:

• Cosmos is a short-day plant and it requires 6-8 hours of sunlight. Try to provide this duration. Any increase or decrease will cause problems with blooming.
• Over-watering or under-watering cause a lot of trouble relating to bloom. Cosmos plants only require water in large quantities at beginning of their growth later they only require one inch of water per week.
• Most of the time the soil containing our plant has not the proper quantity of nutrients, or there is a lack of certain nutrients especially Phosphorus that is required for blooming. Phosphorous is most important for blooming so add suitable fertilizer after checking for deficient nutrients.
• If you are using fertilizers for nutrient deficiency then try to use them at the proper time. Use those fertilizers that have phosphorous, nitrogen, and potassium in them.
• If you notice any insects or other symptoms of disease then use pesticides or fungicides for disease or pest control.
• Before pruning tries to learn proper pruning techniques.
• Try to avoid any mechanical injury to the important parts of plants. Such as any injury to the root will disturb water and nutrient uptake and ultimately the bloom.