I put out a bowl to try and get an idea of how much rain I was getting, and after a really big thunderstorm, there was ~1/2" in it. That doesn't seem like a lot of water for 3-4 days.

Just what are the water requirements for Dahlias? Or what would you think would be ideal? I could put my sprinklers on, but haven't because I thought I was getting a lot of water via the rain.

Cheers,
Russ

I am a newbie as you know, and I'm sure that this answer won't be nearly exact enough for you, but I read somewhere lately that dahlias are a "thirsty plant". I took that to mean that they might need more than just rainwater, and should be kept moist most of the time. But they also like well-drained soil, so they like to have a lot of water, but have it drain away quickly? I guess that keeps the tuber from rotting? Then again, they like the mulch for retaining moisture...all of this kind of confuses me. I really don't know. But there seems to be some pretty in depth info on Dahlia.org...

So far, mine all look happy in the moisture department, I water every third day that we don't have rain. I am more worried about sunlight and air circulation, because I think I planted mine a bit too close together, and it's so humid here that I want to make sure I don't wind up with some kind of fungus on the plants.

Again, I make the disclaimer here that I know you are probably looking for an answer involving actual units of measure and specific time intervals, but I can't seem to nail it down that well...

Well-drained soil...definitely, if you have tubers! See, all of mine are from cuttings and the tubers haven't formed much yet.

Mulch for retaining moisture...definitely, because Dahlias are shallow root plants, their roots run more horizontally near to the top of the soil rather than down and deep. If the soil gets baked, so too could the roots (or at least they'd lose access to water in dry soil.)

I think I'll try giving them some sprinkler water and see what effect it has. At least it might help with the spider mites.

Thanks!!

Cheers,
Russ

My best plant success so far is with the stuff that the neighbors are yanking out of the ground cursing, and ask me, "are you SURE you want to take those? you can't KILL these things!". I figure if others can't kill it if they try, I have a shot at keeping it alive, and it was a really nice thing when we first bought this house and had no money in the budget for trips to the garden center. In my neighborhood, my garden is kind of known as the freebie garden. I have all kinds of ferns, elephant ears, cannas, cast iron plant, mexican petunias, oleanders, and several other things that neighbors donated while trying to eliminate the from their yards.

So I worry about giving advice to others who actually have a method of any kind when I'm so fly by the seat of my pants...Dahlias are the first plant that I've nurtured and watched every day and they are the reason I found the gardening forum! BOY am I learning a lot from all of you!