It sounds like the potting medium is waterlogged and has gone anerobic. Does it smell like rotten eggs?

The rocks in the bottom don't do anything for drainage.

I would unpot the plant and check to see if the medium is soggy. If so, fix the medium with perlite and repot amd remove the rocks.

Hi Balconygirl! I grow in containers and I've had a couple of times where I have a faint rotting smell coming from one or more of my pots. I'm certainly not an expert and maybe someone else will have a better answer for you.

I have to water often because it gets so hot here and I find that the deeper the container, the more likely the smell is coming from that pot. I don't have the smell when it's cooler. Most of the purchased potting mixes have things added like worm castings or some kind of compost materials. I think the smell I get is the high moisture content, heat and those materials all baking at the bottom of the pot. Even with good drainage, it the container is deep, it still stays moister down there than at the top closer to where moisture can also evaporate.

I just repotted some raspberry bushes. 2 were growing beautifully and the roots were extending out and no smell from the soil other than a garden smell. The 3rd bush never grew so it was just literally a stick in the mud. That pot of soil stunk so bad. Maybe the roots taking up moisture and nutrients keep the rotting from happening and with the short roots your grasses have, a shorter pot would be better.

I also will try and make sure that I keep the saucers drained. That stagnant water draining out of the pot can get awful stinky.

I would also lift up the bottom of your pot and see if the gravel didn't shift in the holes and plug them up. That happened to me with a small fruit tree. Poor thing was drowning and I thought it didn't have enough water and kept putting in more.

I hope that helps a little. I'm not sure if there's anything other you can do.

Hi, Thanks for your suggestions ...
The containers are definitely draining, as I see the water come out from the bottom. The grasses look bright and and pretty good. One of the five grasses looks slightly yellow though, they are each in their own pot. I'm not so precise in the kind of smell but it does smell. It's been a hot, humid week with alternating days of rain. Being on the balcony, the pots just get some spray in but I think the rain itself keeps everything damp. I haven't watered them since the first water last Saturday, and am hoping for a good dry stretch of weather starting Monday.

In terms of repotting, I am hesitant to do that since the grasses and their containers are part of the overall design I have in mind for my balcony. The grasses can over-winter providing interest through the year, and a re low maintenance and also provide some needed privacy. Could you suggest another great container liking grass about 2-3 ft in height?

Thanks!

Oops nil13! I see now that you meant unpot, fix the soil, and repot. You suggest adding perlite, would peat moss have a similar effect?

You have to research if the species of grasses you are planting like a more acid soil if you are going to use peat moss.

peat moss would have the exact opposite effect of perlite. Most commercial potting media are almost entirely peat already and that is one of the reasons why they get so mucky and anerobic.

Personally I don't know much about grasses, as I don't really want them on my balcony, due to allergies. But I'm growing a daylily, which looks a BIT like a grass.

Try to find out, where the kinds you have, grow in nature (prairie, forest, beach, bog etc) and try to mimic that in your pots.

If you have a shady spot, then I can tell you that I've seen some very gorgeous Hakone Grass (Japanese Forest Grass) outside a Japanese restaurant. They looked amazing (even better than the ones I've seen in ground, I think). about 2 feet tall in those pots.

We have no idea of what kind of potting medium you purchased. Perhaps the ingredients include some sort of animal manure or other 'organic' amendments.

I agree with the likelihood that the lower reaches of your container are devoid of oxygen, which is not a good thing. Perlite isn't going to fix that, by the way ...... unless you're willing to grow in a medium comprised of at least 75% screened perlite.

Grasses prefer soils that are damp and well-drained - media that don't support a significant layer of soggy soil at the bottom of the pot. To achieve those conditions, you'll need to buy or make a soil based on larger particles than peat, compost, composted forest products, coir, sand, ...... like pine bark.

I would make it priority one to make sure the soil you're using is able to offer a home your roots can be happy in. If it can't, there is little hope for a happy plant.

Al

Wow, Thanks for all the info. For the record, these grasses look quite green and upright ... at this time!

The soil is "Vigoro Planter Box Mix", made in Canada, sold only by Home Depot, it seems. It states that it is weed free, but I can't find the soil composition on the bag ... bad sign, I think?

So what I'm gathering is: the grasses could use a smaller container and adjust the soil.

Al suggests pine bark. Is there anything else - other than the above perlite - I can add to the soil? Sand? Or, do you think a shallower container will take care of some of the situation?

My brother suggested using some well-established yellow variagated zebra grass from his garden. Thoughts?