I've a garden that I try not to water too often, if it is really hot and dry then I will water 2 or 3 times a week, but other than that, I let them be. They grow well, but there are a lot of fungal diseases that occur, at least partly because the plot has been used as a garden for many years, and I can't move it.
Primarily tomato blight and powdery mildew on the cucurbits. I know that the blight is from splashing, and plastic under the tomatoes has gone a long way to controlling that. Other than spraying, I don't know what can be done about the mildew on the pumkins.
Then I visited my sister's garden, and everything that she had there was almost 2x the size (not necessaryily 2x productive, but more so than mine). She has automatic watering which she has water for 20 minutes 2x a day (40 minutes per day total). No visual signs of disease, she also has a spot not used before for a garden.
I was thinking that that much water would cause the funguses to spread since they like it moist, but then I thought that more water would result in stronger plants which could fight it off better.
Would I be better off watering more often (as in automatic) or would this cause more problems than it would solve?
When you point out that your sister's plants are twice as large, I wonder if there is a soil fertility difference. Inadequate water can certainly make plants stunted, but you would probably also notice wilting. Fertility has a huge influence on plant growth.
Plant disease is affected by a lot of variables. Diseases like powdery mildew are more affected by humidity than the amount that you water. Humidity of course can be affected somewhat by how you water, for example, the time of day that you water. If you water in the morning and the plants have all day to dry off, there should be less disease pressure than if you water late in the day. Powdery mildew is also more likely to affect plants that are partially in shade.
One of the big variables is the variety of plant that you are growing. Some varieties are more succeptible than others. Your sister may have some varieties that are well adapted to your area.
1. plant resistant varieties.
2. fertilize if necessary.
3. irrigate early in the day.
4. trickle irrigation may help to keep the leaves dry.
5. cross your fingers and always look forward to next year.
Fertility did occur to me, since she has a garden plot that was part of a grassy horse pasture....and all of the different fungus spores probably are not present in the soil there at least not in the numbers that mine have built up.
The watering was the most apparent difference.
My plants do wilt somewhat on occasion(until I water them), and there was the extremely dry week of vacation where they didn't get any water that I think hit them hard.
Powdery mildew always hits in the fall on the pumkins, full sun or not. Not worth spraying at this point...
40 mins a day is a huge amount of water IMO. I'm a big fan of drip irrigation for smaller plots, or soaker hoses for larger beds. Here in dessicated CO we do it because you can lose 50% of the water to evaporation before it hits the ground using an impact sprinkler or the back-and-forth lawn type. Plus it keeps the leaves dry as mentioned.
Does your sister have seriously sandy soil? I and lots of gardeners I know also water when the wilt starts; it promotes strong roots (some would argue that with unlimited water, you don't need to grow strong roots at the expense of vegetative growth).
If you can stand it, you could improve your soil by sacrificing a year: grow a few successive cover crops of a nitrogen-fixing plant like legumes and till them under, then a last smother of annual ryegrass to shelter the soil for winter. Till that under in the spring. You'll add a lot of organic matter, and smother out most of the weeds too.
P.S. I used buckwheat for one smother this year to double as forage. The seed supplier assured me it was regular buckwheat, but the bees never touched it. Oh well...
You could lick several of your problems by raising your beds and mulching heavily with straw. You will rarely have to water, the straw keeps the soil based fungal spores in the soil and not on your plant leaves. It also decomposes over the winter and adds fertility and humus. Many other attributes of raised beds, but some of the other ones I think are important are denser planting shades out weeds, and you never need to till.
Jeesh, I'm getting dysplexic. I thought the topic was watergardening not garden watering :(
I miss my watergarden. Never had a problem with over watering that garden.
As mentioned earlier, if your mildew problem is a result of your watering method/schedule, I suggest to water early in the morning, that way the sun has a chance to dry the plant, so that by the end of the day, you have dry plants. An old gardner suggested this to me and asked "how much do you like going to bed wet?"