How to avoid fungus in a rainy season?

Question

Last summer I decided to grow a tomato plant but I didn't know how to take care of it properly. After 2 months, it had caught early blight fungus. Since I am an amateur gardener, it took me a while to realized that it was fungus and in the mean time other plants were infected as all pots (i grow plants in pots) were adjacent to each other. Some plants such as parsley turned brown (nor early blight) whereas curry plant started to dry out.

I read that one of the main reasons of fungus is overwatering. But winter is around the corner and this time I want to avoid fungus (lesson learnt). What measures should I take to avoid fungus? I can think of the following:

1. Separate pots from each other.
2. Do not overwater plants. Should I cover the plants when it rains for a whole week or more?
3. Seaweed to cover the soil?

Answer 1

The number one reason for disease spreading is growing in close quarters.

Spread your plants out so they aren't growing together or touching one another and so that air can freely blow between them. This will help keep the humidity down in proximity to your plants.

During the rainy season, remove any feeders or saucers from underneath your pots so the water can drain out. Also, since you have this seasonal problem, you may wish to use a soil that drains better and doesn't hold onto so much water.

Answer 2

There seems to be a little confusion here - Early (and Late come to that) Blight only affects plants in the Solanaceae family, so peppers, tomatoes, that sort of thing. It would not spread to other, unrelated plants, so your curry plant and parsley were not suffering from this infection.

Second, you must dispose of the soil in the pot, and sterilise the pot thoroughly before refilling with clean soil and growing tomatoes again. Keep the tomato plant away from your other potted plants, as far away as possible, it might help, it might not, because the spores of Early Blight live on in the soil, and may already be present in your other potted plants, though not affecting those particular plants. Spores also arrive on wind and in water droplets, so to some extent, Early Blight may still be an issue in succeeding years. Link below gives information to try to prevent or manage this fungal infection

http://www.ext.colostate.edu/mg/gardennotes/718.html