Every year I plant the cosmos variety ?Versailles? by seed, as well as ?Seashell?, ?Sonata?, and ?Psycho?, in my garden (Cosmos bipannutus, Hardy to Zone 5). And every year my cosmos reach six feet or more in height, four feet in diameter, and drip with so many flowers it takes me hours to deadhead. Want the same results in your garden? Read on:
The cosmos thrives in drought conditions. But complete neglect will kill it while too much of the opposite will produce, as my frustrated neighbor calls it, 'straggly weeds?.
Here are my rules for growing towering Cosmos:
1.Choose a garden bed in full all-day sun. Cosmos love heat and hate the shade. Good air circulation is always a plus.
2.Start from seed. Your plants will grow a stronger root system if seeded directly into the garden bed. You?ll get better results if you start from seed instead of transplants.
3.Sow your seeds in a bed of loose average soil at least a foot deep. Cosmos like to spread their roots. The bigger the root system the bigger the plant.
4.Fertilize one time when the plants are seedlings. After that fertilize ONLY if your plants look pale. Too much fertilizer causes few flowers to develop.
5.Keep reading for the one vital secret you need to grow towering cosmos, or ?her funky Christmas trees? as a neighbor's boy once described.
When I plant I scatter the seeds across a well-worked sunny garden bed and then work in the seeds with my fingers (like tossing a salad) until the seeds are approximately two inches deep. I then pat the dirt lightly.
Keep the bed moist but don?t drown your babies. Watering in the morning is best. It keeps the seedlings moist during the warmest parts of the day. If your seedlings dry out from heat or extreme wind during the day then water once more. Watering at night can cause your seedlings to develop fungi, as will watering your lawn at night. Moisture plus warmth plus good air circulation is a must for seedlings.
After your seedlings sprout thin till they're six to twelve inches apart. Ease off on the water, but don?t let your seedlings dry out. Remember, the cosmos is a drought plant. But even drought plants need water. Fertilize the seedlings ONE TIME ONLY by spraying them with compost tea.
Compost tea is cow manure left to rot in a bucket of water for a few days. I know, it sounds disgusting. It smells even worse. Compost tea is not only an effective safe and cheap organic fertilizer for the entire garden, but it also helps keep the bugs at bay. Strain the foul-smelling water into a spray bottle and then spray directly onto the plants.
But what is the final vital secret you need to know to successfully grow monster size cosmos? Here it is:
After the seedlings form adult leaves (at four to six inches) carefully strip the lower leaves, side branches, and any buds off the seedling leaving the two top leaves. Your plants will look ridiculous. You may catch yourself apologizing to them (I can?t help it! They look so naked!). Repeatedly stripping leaves until the seedlings reach two feet in height encourages growth. After reaching two feet in height stop stripping. The plants should take off, seemingly growing overnight.
One morning you?ll walk out your door and be amazed by the huge colorful plants in your garden. And then you?ll grin. Allow yourself a snicker or two while glancing at your neighbors? yards. Hey, you?ve earned it after all your hard work! Your monster cosmos will provide you with bouquets clear into the fall.
Be sure to give plenty of flowers to your envious neighbors.
About the Author
Jenny Harker is an avid gardener and writer of all things gardening