What could cause my coriander plant to start browning?

Question

I grew coriander from seeds and the plant has done marvellously well until the last week or two where it appears to have stagnated a little. I noticed that some leaves have began to brown entirely, while others have brown tips.

This is a potted plant in heavy soil. I was very generous with fertiliser, and I do water on most days save for overcast and rainy days. I notice that the water takes a while to be absorbed into the soil. The soil is constantly wet too. I'm afraid I might have planted it in too heavy soil.

There is drainage below the plant. I used a bed of stones in a plastic pot with two holes. But I think the sand might be too heavy.

This plant gets at least five hours of sun, maybe more, on on sunny days, and the weather is sunny and mild year round (São Paulo, Brazil).

Answer 1

You may be watering too much if your soil is wet all the time. The top inch of soil should be allowed to dry out before you water your plants again, and the pot should be allowed to drain freely in between and not sit constantly in water. Constantly wet soil for most plants means you will get rotted roots. Rotting roots below will produce brown leaves above, because the rotten roots can't properly take up water and nutrients for the foliage and the plant eventually has to start cutting back on how many leaves it can support.