One of the main highlights of cosmos plants is their beautiful flowers. Its petals are delicate and paper-thin, yet they radiate with color. The flower’s center is usually a deep hue, surrounded by a ring of lighter shades. Its name comes from the Greek word for “harmony.”
It’s fitting, as the flower’s appearance brings a sense of tranquility. One of the best things about growing cosmos is the plant is relatively easy to care for yet still produces such lovely blooms.
So, it can be quite a disappointment when your cosmos plants aren’t flowering. If your plant lacks its beautiful blooms, don’t fret! There are a few reasons why this might be happening and some easy solutions to get your cosmos flowers back on track.
Main Reasons Why Cosmos Isn’t Flowering
A showy flower display requires several things from the plant, including proper nutrition and care. When one of these needs isn’t met, it can affect the Cosmos’ ability to flower. Here are some of the main reasons why your cosmos might not be flowering:
Insufficient Sunlight
While there are different cosmos varieties, most require full sun to partial shade. This means the plant needs at least six hours of direct sunlight daily. This can be attributed to the fact that these beautiful plants are cultivated in warm climates. If your cosmos isn’t getting enough sun, it will likely result in fewer flowers.
Staying in the shade for extended periods can also cause the plant to become leggy as it stretches out to try and reach the sunlight. If your cosmos is looking thin and tall, it’s likely not getting enough sun.
Similar to other flowering plants, the amount of sunlight your cosmos gets affects its ability to produce flowers. Being exposed to sunlight means the plant gets enough energy to produce these blooms.
The Solution: Move your plant to an area that gets more sunlight. If possible, choose a spot that receives direct sunlight for most of the day.
Soil is Nutrient-Dense
The type of soil your plant is in can also affect its ability to flower. Cosmos plants require sandy soils – one that contains fewer nutrients. You’ll notice that your cosmos will have beautiful foliage in nutrient-rich soil, but this compensates for its lack of flowers.
The Solution: Simply said, the best way to encourage flowering is to replant your cosmos in sandy soil. If you don’t have any sandy soil on hand, you can create your own by mixing together perlite, vermiculite, and sand.
You can also add grit or coarse sand to the topsoil to help drainage.
Proper Fertilization
As mentioned earlier, cosmos plants require sandy soil to encourage flowering. This means you’ll have to be careful not to over-fertilize your plant. Too many nutrients in the soil can lead to lush foliage growth, but the absence of flowers.
The Solution: It’s best to use a fertilizer that’s low in nitrogen and high in phosphorus. This type of fertilizer will help your plant produce more flowers. You can also add bone meal or rock phosphate to the soil to encourage flowering.
Overwatering
While all plants need water to survive, too much of it can be detrimental. This is especially true for cosmos plants, as they are well-adapted to dry conditions. Keeping your soil consistently wet, or watering too frequently, can cause the plant to produce fewer flowers. Sure – you’ll have better-looking leaves, but the plant will sacrifice its flowers.
The Solution: Water your cosmos only when the soil is dry to the touch. Don’t worry – these plants are pretty forgiving and are accustomed to thriving in arid conditions.
It’s also important to make sure your plant has proper drainage. This will help prevent the roots from sitting in water. Root rot is a common problem among plants that are overwatered.
Wrong Timing
Unlike other flowers that bloom in the spring, cosmos flowers bloom profusely when the nights are longer. This means that if you’re trying to encourage your plant to flower during the summer, you may need to plant it earlier on so it can germinate and mature properly.
The Solution: Block out some of the sunlight during the middle of the day. You can do this by placing a sheer curtain over the plant. This will trick the plant into thinking it’s getting longer nights and encourage flowering. Start planting during the spring indoors, so they can be transplanted outdoors once the weather gets warmer.
Why Aren’t My Cosmos Flowering: Final Thoughts
Cosmos and its stunning flower display is one of the best things about summer. However, if your plant isn’t flowering, don’t fret!
Chances are, there’s a simple solution to encourage your cosmos to start blooming. You may be overwatering it, planting it in the wrong type of soil, or not giving it enough sunlight. Simply ensure that the plant gets its ideal growing conditions, and you’ll be rewarded with an abundance of beautiful flowers!