What is Cosmos Bipinnatus?
Cosmos bipinnatus, commonly known as the common cosmos or the old-fashioned cosmos, is a hardy annual grown for its colorful and fragrant flowers. Common cosmos are so popular that they have been designated as the official flower of Arkansas.
This plant can be tricky to grow from seed—the seeds may not germinate if you’re not careful. If you follow some basic guidelines, you can develop a healthy plant from seed in just a few weeks.
Cosmos bipinnatus is an annual that grows up to 3 feet tall and produces long, thin stems with clusters of small, bright yellow flowers appearing at stem tips. It can be used in borders, butterfly gardens, containers, and meadows where it often reseeds itself.
How to Grow Cosmos Bipinnatus Plants from Seed?
Most people don’t know that you can grow cosmos bipinnatus plants from seed. Cosmos bipinnatus is a flowering plant commonly known as “sunflower” that grows in the North American continent and South America. As most people know, it’s an easy-to-grow annual flower and can be planted outdoors during the spring or summer months.
Here’s how to grow cosmos bipinnatus from seed:
- Collect seeds from plants grown from seeds collected from your flowers.
- Take out only the seed heads (the half-circle at the bottom of a single flower) and gently rub them between your hands, so all the pollen is released and transferred to another plant by rubbing on another plant.
- Leave head in place for 12 hours after pollination to allow excess moisture to evaporate. Then remove the skipper as soon as possible before seed pods turn yellow because they will drop if they are left too long after turning yellow before they have matured.
Harvesting Seeds from Cosmos Flowers
Cosmos bipinnatus, or cosmos flowers, are a beautiful addition to any garden. Dried cosmos flower heads can also make fantastic summer bouquets and can be used in arrangements throughout the year. But how do you grow cosmos? Cosmos flowers are grown from seed, but harvesting the seeds from cosmos flowers takes some work. The process of the increasing universe from the source is lengthy and requires patience, so it’s best to wait until there are about ten days left before the last frost to start your plants indoors.
When to Plant Cosmos Bipinnatus?
When your soil is warm, you can sow the Cosmos bipinnatus seeds you bought. They’re tiny, called “cosmos,” so they don’t take up much space, but you have to make sure you give them enough room. Here’s how:
- 1-Dig a hole 4 to 6 inches deep and wide enough for the root ball of each seed head.
- 2-Fill the hole with potting soil and gently press each seed head into place until firmly anchored.
- 3-Water well to settle the soil and make sure not too much water gets behind the roots. Later on, that will drown them when you plant other plants in that spot.
In-Ground Planting of Cosmos bipinnatus
When it’s time to plant your Cosmos, start by digging a smaller hole than your root ball. (A bit of trial and error is okay here.) You can place the bulb in its container on the spot or set it on top of the soil. To determine the depth of the hole, spread your fingers along one side of your root ball and then push them down into the ground until you feel just a little resistance. This will be close to 2 inches deep. Now take a garden fork or sharp spade and cut an X shape at the bottom of each root ball.
Pick up each seedpod from inside its capsule with one hand to sow seeds. If you’re planting several bulbs, consider picking up several pods and placing them directly in position for planting. Using one hand to guide three pods at a time makes this task much easier than trying to do so with two hands using only one finger per bulb as you would with a seed-starting kit. In general, try not to force any pods into position; instead, use gentle pressure against them with your fingertips.
To plant outdoors during May or June, scatter seeds over a moist surface area evenly spaced so they are about 1 inch apart; be careful not to mix them evenly with dry weeds or debris before sowing them–this can cause problems later on when plants grow out in their natural pattern rather than straight up and down as you want it for maximum bloom production (to avoid having multiple heads, that is). For indoor plants that need light but don’t have enough space indoors for pots, you can also sow seeds directly into individual cell packs made from plastic woven mesh fabric sold in gardening shops and online retailers like Amazon; this type of “cell pack” is pre-sterilized on both sides ready for transplanting into larger containers when germination occurs. The plastic mesh teems better when planted directly since there’s no soil holding roots down while they grow out horizontally across it (having roots shoot.
Container Planting of Cosmos bipinnatus
It’s essential to remember that cosmos seedlings are easily damaged by root disturbance, so a good option is to plant them in biodegradable pots. If you prefer something a little more natural, planting in the ground is you don’t have to water them as often, but they do need regular watering if they’re grown in an arid climate.
If your plant does need a lot of water, remember that cosmos plants typically thrive without a lot of it. In fact, according to the Washington State University Web site about growing Cosmos Bipinnatus, “From seed, these plants do not require much water at all.”
Most importantly, cosmos plants don’t need a lot of sunlight either. The Web site says that “These plants can be grown under part-shade or full shade conditions and will still develop beautiful blossoms.”
How to Care for Cosmos Bipinnatus Flowering Plants?
Since flowering cosmos plants are annuals, gardeners must start from seed to grow their plants. Although the plant is often available at retail locations, you can easily buy seeds online and start from home if you want to grow your own.
Growing cosmos from seed is easy and rewarding for new gardeners. Follow these steps:
Plant the seeds indoors in a pot filled with soil six weeks before your last frost date. Allow the soil to become completely dry during this time. When you’re ready to plant outside, dig a hole just slightly more profound than the seeds are tall and bury them 1/2 inch below the soil surface (they should be no deeper than an inch). Be sure that each source has its little pocket of loose dirt around it to germinate properly. Space out your seeds by planting them 4 inches apart in rows 18 inches apart. Cosmos will do best when grown in full sunlight—but not too much hot sun; they prefer half-shade!
How Often Do You Water a Cosmos Bipinnatus Plant?
When growing cosmos from seed, your watering frequency is going to vary. The key is to pay attention to how often you water each plant. To help with this, you should note when and how much you are watering the majority of your plants. For example, suppose most of your plants require daily watering during the summer months but only occasional waterings in late fall and winter because of less frequent rain and lower temperatures. In that case, it’s safe to assume that cosmos also need daily watering during the summer months but only occasional waterings in late fall/winter (unless you live in Southern California or some other place that doesn’t experience seasons).
If you are sensing that one of your plants isn’t getting enough or too much water, take the time to check on its soil. Soil should never be soggy or dry. It should feel moist with a consistent texture for easy scooping with a finger or two. If it feels soggy at all, wait a week or so and check again before deciding whether or not it needs more frequent watering than usual. If it feels dry, consider giving it extra attention until its soil feels moist once again (be careful not to overwater!).