Well, here is my opinion. I will have to say that my plants range from 5-10" tall that are in SOLO cups in small 8oz and 16oz. I have them in a greenhouse in a south facing window and I usually bottom water once a week without ill effects. I just watered last night after about a week and a half. I would just do a good bottom watering and you should be fine. YMMV. I am in zone 3 and thermostat is set at 74. I hope this helps some.

I bottom water ALL my seedlings, ONCE a week, THOUROUGHLY. Let them sit in water for an HOUR. Then take them out and let the excess water to drain out and then put them under the light. So 3-4 day should not be a problem at all.

I wouldn't let them sit in water while you're away.... Asking for trouble.

Whether solo or 4", I bottom water for about a half hour and let drain. That's more than enough for at least a week unless they need potting up anyhow. I also top water occasionally to flush out the salts.

Kevin

I think there might be a little confusion with bottom watering. Some people consider it to be doing what Seysson described where they let them sit in water and get saturated from top to bottom, then pull it out and let it drain before putting back in its tray. Others consider it to be putting a layer of water at the bottom of the tray that is maybe a half inch or so and letting the water wick up into the containers from the bottom on a nearly continuous basis.
Bruce

I dont leave them in water except when I am watering. I just want to make sure that they are well watered. Letting them sit in water, even in wet saucer can cause problems, I think.

Do these solo cups have holes in the bottoms?

Well, mine do.... They do not come this way, although it would be cool. I just use a soldering pencil and make 5 holes in the bottom. There are many other ways, but I just did it this way and it works rather well.

that's good idea obchili... I've been just using a heated up knife. Forgot about my soldering pencil!

Kevin

I just heat up an old phillips screwdriver over a piece of charcoal soaked in lighter fluid and do a stack of 10 of them at a time, 5 holes in each.

Tried my first hand at solo cup watering with one big dime sized hole, and two or three smaller ones I poked with a knife. Got about a dozen going right now in the tray.

After a half hour, it does not seem the dampness has reached anywhere near the top. Should it be completely saturated on top before I end the process? I'm just not sure how far I should take it..

How deep did you plant them when you put them into the cups? If you think the roots are still, say, only in the top half then I would let them sit in water until you see the top just start to darken - not get soggy. Then let drain but the nice thing about bottom watering is not too much will drain out (compared to top watering where a lot might just run right through). 3-4 days without water should be fine, if the soil is moist that's a lot of volume and they won't dry out in that time.

Do you have your lights on timers?

Yeah, lights are on from 6am-9pm.

I would say the roots have reached halfway to two-thirds down the cup at this point. From what you're saying, I should let the top get damp. Could this take over an hour?

If they're down below half then maybe you don't need to let the top get so wet, but it's hard to tell how deep the roots go. That's why I don't like to use such deep containers (though I have used the cups for tomatoes, b/c I don't fill them, can add more medium as the plant grows taller).

If you really think the roots are that well developed, then no I don't think you need to see the surface darken/moisten, since peppers don't like as much water as tomatoes, just leave the cups in a couple inches of water for 30-60 minutes depending on how dry they are right now, til they're heavy and let drain well. o this the day before you leave, not *right* before, so if you leave them in too long and they drain quite a bit you can empty the tray and not leave them sitting in water. Or if you don't leave them in long enough and they feel a little light later that night, or plants look a little wilted b/c the water hasn't reached the roots you can (carefully) water a little from the top if needed.

When was the last time you watered them, and how often have you been watering?

I place the solo cups in a deep water/nutrient/h2o2 bath until they are fully wet to the top, about 5 minutes then put them back under the lights. Watering fully to the top encourages the roots to grow everywhere resulting in a tighter root ball. Bottom watering with too little water will encourage the taproot to grow down to quickly in search of the water and inhibit all the cool little hairlike roots from spreading throughout the cup.

5 minutes? My dime sized holes on the bottom (and newer small holes surrounding it) must be set up wrong. After an hour, the dampness barely gets halfway up.

Take scissors and snip around the bottom edge. 5 minutes seems a bit too short to me to thoroughly wet a 16 oz cup but definitely within half an hour you should see some darkening of the surface. If it's taking more than an hour, I wonder how long it's taking to drain - that's more of a problem.

As it's 2/1, it's time for me to start thinking peppers again, and trying to avoid mistakes of 2014.

Brings me back to this post. I liked transplanting from cells to red solo cups, but I just couldn't figure out the bottom watering thing. If I watered from the top, some of the cups got too soggy. When watering from the bottom, very rarely would the water "wick up" and saturate to the top of the soil.

This makes me wonder if a) I was using the wrong soil mix and b) if I was compacting too much soil mix in the cups. Any ideas?

I took a 1/4 inch drill bit and made 4 holes at the bottom of my cups evenly spaced around the bottom. It takes about 20 minutes for the soil to darken at the top. Although I think next watering I need to flush the soil to get the salts out. The top of the soil is looking a little crusty.

I had plenty of holes on the bottom of my cup, so I don't think that was the problem.

Try a bit more water peps22. Also, don't worry if the water doesn't make it to the soil line after 20-30 mins. It will eventually wick up. Get an idea for how much a saturated cup of soil weighs and how much a bone dry cup weighs.

Kevin

i use a fresh razor blade ... and simply cut the bottom edge where it turns 90 degrees from sidewall to bottom ... slicing 3 drains ...

i wonder what kind of fumes you are getting on the red hot poker method

one other thought.. if you cant go 4 days w/o watering.. you might want to think about a pot over stuffed with roots.. and time to up pot ... either your media is failing.. or there isnt enough there ...

of course.. if you are leaving town rather soon.. repotting the whole flock probably isnt an option ...

ken

Never having used solo cups I read every post, with 5 to 60 minutes to fully bottom water being reported? I believe you're on the right track peps22, "This makes me wonder if a) I was using the wrong soil mix and b) if I was compacting too much soil mix in the cups.". With so many different commercial & homegrown mixes it makes me wonder if this isn't the heart of the matter? I've always used Jiffy Peat Pots and when bottom watered the seed starting soil always gets wet to the top in 10 - 15 minutes.

peps22, how deep is the water you are setting the cups in? If the depth of the water isn't close to the depth of the cup it will take forever to wick up.

I don't use solo cups much for pots but when I do I bottom water with a setup similar to this. The cups with many slits in them are hot glued to the tray and stop the planted cups from tipping over. Just drop a planted cup into one in the tray, the water should be almost full and added as the planted cups soak it up.

{{gwi:2131076}}Even with completely dry media (I use pro mix bx) which is hydrophobic it only takes about 10 minutes for the top to show moisture. The cups are then set in another tray to drain. Before putting it back under the lights I tilt the pot at a 45 degree angle to drain off the perched water table.

Hope this gives you some ideas.

SCG

SCG, in my situation, the depth of the water was not even close to the depth of the solo cup. I simply put them in my seedling tray (2" depth, tops). So what you're saying is..... I was never a physics major in college!

I'm looking forward to using a deeper container this time, and trying again... thanks!

This post was edited by peps22 on Sun, Feb 1, 15 at 16:58

Lol Peps22!!

I am not sure the quantity of cups you are doing but you also can fill another cup nearly to the top with water and set a planted one inside. I came up with this design because the cups kept tipping over when they floated around my tray.

Would love to see pics of your plants. I am trying hot peppers for the first time this year.

SCG

I'm having a really hard time getting this watering thing figured out.

How much water is taken up by the media when you water?

For example, say you're using a 16 oz solo cup, how many ounces of water will be absorbed assuming the soil was pretty dry when you started?

In Massachusetts I start my seeds on 3/1. Last year I used a heating pad for germination for the first time, and I found that even 3/1 was too early. I grew the best seedlings ever, but I went on vacation the first week of May and 30 seedlings died with my pepper-sitter. So, round and round we go. I'm really hoping to make this bottom watering thing work.

peps22, you reside Taxachusetts too? I'm in the NE corner between Haverhill and Lowell.

I agree with March seed starting as I find keeping the seedlings from getting leggy a chore. Good luck this year!

i put an inch of water and leave it there(should cover the bottom of cup a little). they will soak it up in 24-48hrs.. Water when the soil is dry again, usually like 5 days. (you can tell by feeling how heavy the pots are once you get some practice)

Solo cups have 2 holes in the bottom made by using a hot dog / marshmallow roaster, heat up the prongs on your stove and it'll melt through the cups easy peasy.

{{gwi:2131077}}
{{gwi:2131078}}

and here they are 3 months later if you don't believe this method works..
{{gwi:2131079}}

This post was edited by JonOklahoma on Mon, Feb 2, 15 at 9:29

Thanks for the pic JonOklahoma, I was wondering how big they would get in 3 months....this answers it perfectly!!!

SCG

NE Chileman - Merrimack Valley, huh? Do you get frost earlier than us in MetroWest?

I used to start my seeds around 2/15. I decided to start two weeks later last year, and wonder if I should even push to 3/7 this year. I've found no gain in getting the seedlings outside in early-mid may. It can get so rainy and cool in May that I don't even bother putting them out until Memorial day.

Heating pad for my seedlings was one of the best things I did new last year.. Now I just need to master watering cups!!!

SCG, below is a pic of my plants exactly on May 1. Kind of makes me sad, they were all dead 2 weeks later :-(. I am zone 6b.

Maybe they should be bigger, but my room temp never exceeds 65 that time of year.

This post was edited by peps22 on Mon, Feb 2, 15 at 11:52

SouthCountryGuy, thanks for the info - this is exactly what I was looking for.

Merrimack Valley, huh? Do you get frost earlier than us in MetroWest?

Depends on where in MetroWest you hang your hat.