How often to water containers on drip?

supergirl · July 14, 2006

In an effort to avoid BER, I've been watering at intervals throughout the day, trying to keep the soil evenly moist. Now that it's hot I'd set it to 4x per day between 8 AM and 5 PM, for 10 minutes per watering. This seems to keep them from drooping at all, so I thought I had it down. However, I noticed that one stem on one Black from Tula was wilting; on close inspection, it kind of looks like the stem is rotting. I'm assuming this is from being constantly wet. I cut off that stem and used Daconil in hopes of saving it so I can at least ripen up the tomatoes on the rest of the plant. Note: I had been using copper fungicide and Serenade both before this point, but they clearly didn't help with this, and I do NOT want to lose my plant. When I checked many of the others, they also had some browning at the bottom of the stem. Pulled back the cocoa mulch and gave them a little spray as well.

Should I be watering fewer times for longer, maybe 2x per day for 15 or 20 minutes? I think that's what I did last year, but I thought I was being clever and lessening BER. I'd much rather have BER than have dead toms because I rotted the stems. I've also tried to move the drippers away from the stems. I know experimentation is the best way to learn, but I'd appreciate knowing what those who are already more experienced do! :wink:

Mantis · July 14, 2006

One thing.
Browning at the bottom of the stem. Pulled back the mulch.
Never let mulch rest up against the stem of the tomato. When you put it on, make sure there are few inches of space around the stem that are clear of the mulch. This seems to be the advice of many folk and not just me. This is true for many plants not just tomatoes.
Just a thought. Could you get a container dish under one of your containers. If water pools in the dish at the end of the day then prehaps you are overwatering. If not, they may need more water.
Cheers Mantis *who is himself coming to terms with growing things in pots*

MsCowpea · July 14, 2006

You could get an inexpensive plant moisture meter for aorund $15 and test the soil to arrive at the proper level to run your drips. The recommendations always say evenly moist but unless you have perfect drainage trying to accomplish that just leads to overly saturated plants. Once you know what it truly going on you can forego the testing. Good luck with your plants.

supergirl · July 14, 2006

Thanks! They all have dishes under them, and I have been using that as a measure of whether they're getting overwatered. I started out with less water, had some drooping on the hot afternoons, added more. A couple of the dishes have a tiny tiny bit of water, just barely covering the bottom of the dish, so I thought I'd kind of hit the right balance. None of them get any real accumulation of water.

I suspected the mulch against the stems was a bad thing, but this is my first go with mulching, so I wasn't sure. I sort of rationalized it that you bury a bunch of the stem when you plant, so the stem doesn't mind being covered. However, that seems to apply only to dirt, not damp cocoa hulls (which I've already whined about elsewhere and will not use again.)

bowtie · July 19, 2006

My container plants get 25-30 minutes at about 11am with 1 gallon/hr drippers, once per day. Temps here are 85-90. I also fertilize daily thru the drip. I don't mulch the containers as the plant canopy usually covers everything up by mid-season.

I think with 10 minute intervals you may be watering your mulch more than your plant. Pull the hulls away from the stem and position the dripper in a cleaned away spot. Cocoa hulls can also get moldy, maybe a fungus attacked an open wound near the soilline too.

Try 2x or 3x at 20-25 minutes in extreme heat with something like 1gph drippers. If you have pans underneath, see how much water collects when the line shuts off, and check it an hour or 2 later (before the next cycle) to see if it all got sucked up.

Also, what gph drippers are you using?

supergirl · July 24, 2006

Thanks Bowtie. Almost all plants are on 1 GPH drippers, with the exception of two plants that seemed to need more water (they're at the end of the dripline, so maybe the pressure wasn't holding up), so they got adjustable ones, which have been adjusted such that the plants don't droop, but don't have a bunch of standing water in the saucers.

I think it was the mulch. Pulled that away and the problem seems to be getting better (serves me right for being foolish about it in the first place when I had a feeling that might be bad). One of the Black from Tulas still seems a bit sickly, but the others seem much recovered. I've also adjusted the water to 2 longer waterings. They're against the south wall of the (light-colored) house, and it's been close to 100, so they have a hard time by mid-afternoon if they don't get more water then. I may play with the mulch next year, some with and some without, and see how that does.

July 14, 2006	#1
supergirl Tomatovillian™ Join Date: May 2006 Location: Palo Alto, CA Posts: 107	How often to water containers on drip? In an effort to avoid BER, I've been watering at intervals throughout the day, trying to keep the soil evenly moist. Now that it's hot I'd set it to 4x per day between 8 AM and 5 PM, for 10 minutes per watering. This seems to keep them from drooping at all, so I thought I had it down. However, I noticed that one stem on one Black from Tula was wilting; on close inspection, it kind of looks like the stem is rotting. I'm assuming this is from being constantly wet. I cut off that stem and used Daconil in hopes of saving it so I can at least ripen up the tomatoes on the rest of the plant. Note: I had been using copper fungicide and Serenade both before this point, but they clearly didn't help with this, and I do NOT want to lose my plant. When I checked many of the others, they also had some browning at the bottom of the stem. Pulled back the cocoa mulch and gave them a little spray as well. Should I be watering fewer times for longer, maybe 2x per day for 15 or 20 minutes? I think that's what I did last year, but I thought I was being clever and lessening BER. I'd much rather have BER than have dead toms because I rotted the stems. I've also tried to move the drippers away from the stems. I know experimentation is the best way to learn, but I'd appreciate knowing what those who are already more experienced do! :wink:

July 14, 2006	#3
MsCowpea Tomatovillian™ Join Date: Jan 2006 Location: S. FLorida / Zone 10 Posts: 369	You could get an inexpensive plant moisture meter for aorund $15 and test the soil to arrive at the proper level to run your drips. The recommendations always say evenly moist but unless you have perfect drainage trying to accomplish that just leads to overly saturated plants. Once you know what it truly going on you can forego the testing. Good luck with your plants. __________________ "When we kill off the natural enemies of a pest we inherit their work." Carl Huffaker

July 19, 2006	#5
bowtie Tomatovillian™ Join Date: Apr 2006 Location: Spudleaf's old stompin' grounds Posts: 11	My container plants get 25-30 minutes at about 11am with 1 gallon/hr drippers, once per day. Temps here are 85-90. I also fertilize daily thru the drip. I don't mulch the containers as the plant canopy usually covers everything up by mid-season. I think with 10 minute intervals you may be watering your mulch more than your plant. Pull the hulls away from the stem and position the dripper in a cleaned away spot. Cocoa hulls can also get moldy, maybe a fungus attacked an open wound near the soilline too. Try 2x or 3x at 20-25 minutes in extreme heat with something like 1gph drippers. If you have pans underneath, see how much water collects when the line shuts off, and check it an hour or 2 later (before the next cycle) to see if it all got sucked up. Also, what gph drippers are you using? __________________ By three methods we may learn wisdom: First, by reflection, which is noblest; second, by imitation, which is easiest; and third by experience, which is the bitterest. I'll be back... bigger, stronger, faster, better...

July 14, 2006	#2
Mantis Tomatovillian™ Join Date: Jan 2006 Location: Oz Posts: 1,241	One thing. Browning at the bottom of the stem. Pulled back the mulch. Never let mulch rest up against the stem of the tomato. When you put it on, make sure there are few inches of space around the stem that are clear of the mulch. This seems to be the advice of many folk and not just me. This is true for many plants not just tomatoes. Just a thought. Could you get a container dish under one of your containers. If water pools in the dish at the end of the day then prehaps you are overwatering. If not, they may need more water. Cheers Mantis who is himself coming to terms with growing things in pots

July 24, 2006	#6
supergirl Tomatovillian™ Join Date: May 2006 Location: Palo Alto, CA Posts: 107	Thanks Bowtie. Almost all plants are on 1 GPH drippers, with the exception of two plants that seemed to need more water (they're at the end of the dripline, so maybe the pressure wasn't holding up), so they got adjustable ones, which have been adjusted such that the plants don't droop, but don't have a bunch of standing water in the saucers. I think it was the mulch. Pulled that away and the problem seems to be getting better (serves me right for being foolish about it in the first place when I had a feeling that might be bad). One of the Black from Tulas still seems a bit sickly, but the others seem much recovered. I've also adjusted the water to 2 longer waterings. They're against the south wall of the (light-colored) house, and it's been close to 100, so they have a hard time by mid-afternoon if they don't get more water then. I may play with the mulch next year, some with and some without, and see how that does.