Yes normally you just dump the extra out. It's not like you are going to fill the tray full of water anyway. You just pour in an inch or so until the tops of the soil in the plant cells shows damp then dump any left over.

Just get some sort of a pan/bowl/container near your seed staring area to dump the water into.

Dave

When you've done it a few times you'll probably be able to judge the amount so as not to have any water left in the bottom to tip out.

wow - you don't leave some water in the tray/pan?

wow - you don't leave some water in the tray/pan?

No way. That guarantees you root rot and damp-off. Soil needs to dry out some between waterings or the roots are deprived of O2 and the soil surface develops molds and fungi.

Dave

oh thanks Dave - then I've really misunderstood this.

So you put ALOT of water in the tray, and wait for it to get soaked up to soil level, then empty.....At what age do you start this? After taking the dome off I would think - not before sprouting?

You need to do it as soon as you sow the seed t-bird. You need to get the sowing medium thoroughly moist, but not sopping wet. Seeds won't germinate in dry soil. Thereafter do it when the medium has dried out but before it's dust.

Bottom watering is begun after the seedlings emerge and of course by then the humidity dome has been removed. It is used until transplanted to the garden. No, you don't put alot of water in the tray.

Depending on the size of the cell packs it can take very little water. In a standard 1020 tray less than 3/4-1" of water is normally more than enough. The goal is to just lightly moisten the soil in the cell packs, not drench it. Overly wet soil kills seedlings.

Keep in mind that roots need O2 and air spaces to expand in even more than they need water.

Dave

DD do you wet your medium before you put it into the tray/pots? I always put the medium in dryish, sow the seed and then bottom water immediately to get it moist. More than one way of doing it clearly. I also seem to leave the dome on longer than you (with the vents open).

DD do you wet your medium before you put it into the tray/pots?

Yes I do. My medium is thoroughly wetted first in a separate container, then hand wrung out, cells filled, lightly compacted, then seed added.

When I posted above your post wasn't showing up for me or I would have added that info.

Dave

OK, DD, I see. I don't like the mess of dealing with wet medium so I wet after it's in the pots/trays. Cats, skinning, methods, etc.

I never start with dry mix, but the other day I was starting one tray so just dipped it into a seed tray filled with small square pots and spent 2 days trying to get it moist enough to plant into. Never again.

I normally put the seed starting mix into a dish pan and put hot water in the pan and stir it around until the mix is moist. Then I move it to the seedling tray and plant. I have a lot of small pots, or sometimes I use soil blocks, all depends on what type of seed I am planting. I never use peat blocks or pots and don't recommend them. They are difficult for new gardeners to use, and most experienced seed starters have learned that they don't need them.

In a seed starting medium that I have used, watering from the bottom would never allow enough moisture to the seeds unless the medium was already damp. It might wet the bottom, but it would take days (if ever) to wick the water from the bottom to the top of dry mix. I know a man that fills his trays dry then puts them out in the snow for a couple of days or in a cold frame and covers them with snow. I just find it easier to use a pan and hot water from the faucet. The mix moistens easily and is comfortable to work with.

It must depend on the mix you use. The stuff I get is John Innes seed sowing compost and is already moderately moist in the bag. I have never had any problems with wetting it and the directions on the bag actually say to fill the containers first then water. It doesn't float up or anything. Basically, I just hold the cell trays/pots over the open bag and scoop in the medium. Then place in the drip trays and water into the bottom tray. The mix is clearly key.

Keep an empty 5 gallon bucket with you to dump the extra water in so you don't have to make a lot of trips back and forth.

I work in a greenhouse setting and start many many seeds with a similar method. I use a moistened medium, normally a metromix soil, one withouth perlite but a higher percentage of vermiculite and/or bark as it takes a little longer to dry out. I generally use 1020 flats w/o holes and 50 cell plug flats to insert. I also have another flat that is similar to a basket, woven plastic though I don't recall what they are called, this I place the plug tray inside of and both into the flat. After watering thouroughly I can remove the plugs from the excess water if need be and simply set on the table beside them, we have tables made out of expanded metal so it allows for good ventilation. I find that pouring off excess water after letting the soil soak you lose an awful lot of the the soluable nutrients form the soil and rather than having to replace them through fertilizers, just re-use this water. Even use it to water other plants.

The amount of water to use is very dependent on the size of the pots/cells. 50 plug flats, I tend to put in about 1" of water for maybe 15 minutes, really dry 1 gallon pots I usually set in a couple inches of water and let them set for a number of hours so even the top levels of soils become saturated.