I planted some cosmos from seeds in a clay pot. The pot is 4 inches high and the plant is 11 inches from the top of the dirt. When should I move it to another container? Also, the stalk has about 2-3 inches with no leaves. Do I put the soil up to where the leaves are growing or do I leave it that way? There are about 8-10 plants in the same container. Do I need to separate each one?
Once the plant has 1-2 sets of "true" leaves, they can be moved. The soil in their new pot should be at the same level on the stem as the old pot. Separating them will help prevent root cramping, but if their eventual home is all in the same container, you do not need to separate them. If they will be planted out in open soil, separating them will help them develop stronger root systems.
What is the orange flower called that looks like a cosmos but is shorter and smaller?
There are too many plants that qualify to accurately answer your question but try goggling for heliopsis. There are many varieties and you may find what you are looking for. There are some varieties that are orange-yellow.
I made the mistake of planting two 25 cent seed packets of cosmos in my garden and promptly forgot about them. I neglected to stake them and they grew horizontally, about 4-5' long. When I cut them back after flowering, I had to use an AXE, some stems were 8 inches in diameter. I did not dig them up because they were labeled annuals. Please tell me these things aren't going to come back next year.
While most Cosmos are annuals, there are perennial varieties. However, unless yours dropped seeds, it is unlikely to return. If it does, you can promptly pull it up and discard it.
Received by mail, not sprouting. How do you know which end to plant? Both ends look the same, no crown. Not sure what to do.
Regardless of how you plant them, the right end will come up. Plants naturally have systems in place to ensure even if they are planted upside down, they will grow right side up.
That being said, you should notice that one side of the rootball has more of the finer roots than they other. This is the side that goes down. The plant will come up quicker if planted the right side down, but in the long run, it does not make a difference.
Eight years into my wildflower garden, which was great the first couple of years on virgin soil after new construction, I'm now faced with some questions. My lawn service, by mistake, fertilized it last spring, so what grass was there became large patches of dense grass. Impossible to scratch to add new seed. Do I rototill it and try to start again or just let ordinary weeds take over the grass? By end of season (now) it looks fairly interesting, with tall, graceful plumes of seedy weeds mixed with cosmos. What's the best treatment for end of season? Let it dry out and fall over in the winter? Mow it now or in the spring and clear cuttings? Just leave it?
If you like the interesting plumes and seed heads, then I would leaves it as is until spring, at which time you can mow it down and replant. Otherwise, you can perform some fall clean up now.
I've sown some Cosmos seeds in trays that have come up very tall and thin (spindly). Is this normal and will they fill out eventually?
They have too little light. They need either a brighter window or you need to get a fluorescent bulb and place that a few inches above the seedlings.
Cosmos plant twisting and curling. Why?
While cosmos are generally pretty tough, there are a number of factors that could cause this, such as viral or bacterial disease, bugs such as aphids or thrips, or imbalance in fertilizer, pH, even insecticide chemicals.
This article has general growing information: https://www.gardeningknowhow.com/ornamental/flowers/cosmos/growing-cosmos.htm
If the problem is affecting too many plants, or seems to be worsening, you might want to take samples to the Extension Service, where they can analyze and suggest cures, This article will help you find one: https://www.gardeningknowhow.com/extension-search/