Plants that drown

[Corzhens]

I bought a cosmos plant in a pot late last year in one of our trips to the province. It was a foot high with plenty of branches and flowers. A few days after, it rained hard that drenched the cosmos. All along, we thought that the plant liked the wet weather since it is ordinary for plants to thrive when it is wet. Unfortunately, the cosmos withered before the week was over. And it failed to recover and died. There were 2 pots that I bought and they bought died so we surmised that too much water drowns the cosmos.

 

[splinx]

There were 2 pots that I bought and they bought died so we surmised that too much water drowns the cosmos.

Yea, that's what I found too. It seems they do not like much water.

Hot dry conditions, along with poor to average soil are optimum conditions for growing cosmos.

Very little maintenance is required. You should not need to water them, unless there is a prolonged drought, and even then, the water would be better used elsewhere.

 

[remnant]

I would like to know more about cosmos. Judging from your discussion, it is a xerophyte or plants that thrive in dry conditions. What is it used for? It sounds like a decorative plant.

 

[Trellum]

Oh no, I'm so sorry to hear that I have yet to drown a plant, but I've definitely gotten a few plants frozen over the course of the years (not covering them in time thinking the cold wasn't bad enough just yet...). it happens even to the best of us

 

[Greenhorn]

Cosmos are tall lovely flowers that I grow in my garden. In general they require only a little water.

That said plants do not drown (ingestion of water), the reality is they die of Asphyxiation (lack of oxygen) due to water taking up soil space where oxygen needs to be. It's not really too much water, it's no oxygen.

I would have to say that the soil that the Cosmos were in was to heavy or the container did not have the correct drainage needed.

Definition

Air can fill soil pores as water drains or is removed from a soil pore by evaporation or root absorption. The network of pores within the soil aerates, or ventilates, the soil. This aeration network becomes blocked when water enters soil pores. Not only are both soil air and soil water very dynamic parts of soil, but both are often inversely related:

• An increase in soil water content often causes a reduction in soil aeration.
• Likewise, reducing soil water content may mean an increase in soil aeration.
• Since plant roots require water and oxygen (from the air in pore spaces), maintaining the balance between root and aeration and soil water availability is a critical aspect of managing crop plants.

Pore space: Soil particles rarely fit together tightly; they are separated by spaces called pores. Pores are filled with water and/or air. Just after a heavy rainfall or irrigation event, pore spaces are nearly 100% filled with water. As time goes by, the water passes through the soil, or evaporates into the air, or is used by plant roots, and more of the pore spaces are filled by air.

Pore space generally occupies 30-60% of total soil volume. A well-structured soil with both large pores (macropores) and tiny pores (micropores) provides a balance of air and water, both of which plants need. Macropores provide for good drainage, and micropores hold water that plants can access.

 

[Beverly]

Cosmos are native to Mexico and grow wild here. I also have them in my garden. They are nectar rich and popular with all pollinators including butterflies. I have never had one die due to too much water, but during the rainy season, the downpours always knock off all the flowers and when that happens i generally pull them up in favor of some flowers that will survive the rainy season. I know they will come back after the rainy season which is traditionally June through October. They come back, not because of the roots but because they reseed. When they are planted from seed, they grow very well if the weather is warm enough (which is year around where i live in zone 11). I save seeds to plant each February and they give me 150% germination In the wild places where they grow naturally, fields and other open areas, they bloom in October, which is supposedly after the rainy season (although it is getting harder and harder to predict). February is a good time to plant seeds in my zone. I just toss some seeds on some fluffed up soil (so they don't blow away), they don't need to be covered, but they will germinate if they are watered in as seeds and watered when they are seedlings. I also give them some water from time to time when they are growing in the dry season, but that may not be necessary if you have some nice humidity. I have never seen cosmos plants offered in nurseries, but i have tried to move some from time to time and my experience has been that they do not transplant well (which may have caused your problem). It may have been the transplant and not the water. If you left them in the pot, then i suppose it was the water or lack of oxygen or both.

 

[Daren]

Cosmos Mmmmmm There is a word that comes to mind straight after I plant them & that is Rabbits lol They love to get a nibble of the Cosmos in my garden so I Have to protect them with sharpened sticks I love rabbit stew with a hint of Cosmos

 

[Sheal]

Cosmos, both pink and white in this picture. They are annual plants (living for one year) and grown from seed. My soil is sandy and free draining so they are at home here.

 

[Beverly]

Do the bunnies show a preference for the Cosmos over other plants @Daren? This is interesting to me if they do, because now i need to wonder why? My garden is walled so the bunnies and skunks can't get in so i've never had this problem. Come to think of it, nothing much bothers it except the slugs but they will eat anything. But not this year because i have placed some copper tubing to protect some of the planted areas just in case the slugs and snails haven't learned their lesson yet.

 

[Beverly]

Those are lovely @Sheal ...Cosmos bipinnatus, such delicate foliage.

 

[Sheal]

Thanks Beverly. I'll be growing five different types of Cosmos from seed this year.

 

[Corzhens]

I would like to know more about cosmos. Judging from your discussion, it is a xerophyte or plants that thrive in dry conditions. What is it used for? It sounds like a decorative plant.

Cosmos is a flowering plant which looks good for a decoration indoors. I really do not know anything about it. I only bought it because the flowers caught my fancy. Even my husband was kind of surprised when it started to wilt due to the frequent rains. Here is the pic of that cosmos that I bought. One was already replanted in a pot while the other was still in the soft plastic pot. And it both died a few days after that pic was taken.

 

[Beverly]

@Corzhens... these plants don't look like any Cosmos i have ever seen. They look more like mums or marigolds. There are two species of Cosmos that i know of Cosmos sulphureus and Cosmos bipinnatus. @Sheal has already posted a photo of C.bipinnatus above in this thread and here is a photo of Cosmos sulphureus. I don't think you have Cosmos there at all.

 

[Sheal]

I agree with you Beverly, Corzhens flowers are Marigolds not Cosmos.

 

[Corzhens]

Gee, thanks for the info, @Beverly and @Sheal, that just goes to show that I'm more of a vegetable gardener than flowers. I actually bought 2 flowering plants and from what I remember, the vendor said Marigold and Cosmos. The yellow one was the marigold to me and this orange is the cosmos. So maybe it is the other way around? Again, thanks very much for the information. That's added knowledge to me. By the way, I have a marigold seedling and it looks good. I will post the pic later.