STARTING MIX NEEDS TO BE WETTED

897tgigvib

Garden Master
Joined
Mar 21, 2012
Messages
5,439
Reaction score
925
Points
337
Several topics here recently have mentioned problems with using starting mix.

One of the main causes of sudden death for seedlings or cuttings is dry mix.

Starting mix, or most fine potting soils used as such, has a phenomenon. something about, if you think you've watered it, not all of it in the cell or pot gets actually wet.

One of the smarter persons can use better words I'm sure.

But try this. Get a pot. fill it with starting mix or potting soil right from the bag. Now water it a little, like you might be moistening that tomato seed. Wait a while. come back to it and carefully dig through it. use a teaspoon. often you will find dry spots in it...some spots so dry almost like static...that's exagerrating...but, picture the poor baby's only root hairs in the dry spot.

>>>to add to confusion, some bags already have premoisture, some don't, and some did but may have dried out<<<
 

thistlebloom

Garden Master
Joined
Dec 1, 2010
Messages
16,473
Reaction score
17,414
Points
457
Location
North Idaho 48th parallel
Very true Marshall. I think mixes that contain peat tend to be slightly hydrophobic and need more attention to watering before planting.
I find that bags that have been opened and the soil has dried out can be really resistant to absorbing the water at first.
I add warm water right into the bag and stir it around a bit before I use it, even with new bags when the mix fills moist already.
 

897tgigvib

Garden Master
Joined
Mar 21, 2012
Messages
5,439
Reaction score
925
Points
337
Yea, hydrophobic. That's the word.

Sometimes those bags can be too full or clumsy to add water to. Dump some into a bucket and do it in that for the first round from the bag, just with what you'll be using. Don't need to make mud pies out of it. Start with a little, mix it in, then add more warm water.

When ya put it in your pots, flat, or cells, put it in loosely, and don't tamp down. Just muush it in place tith your finger pad.

One of the important things that especially baby roots need is air. A lot of beginners and intermediates might not know that. That doesn't mean big huge gaps of air, but little fractions of a millimeter sized pockets of air. Don't need to measure the size of them, well, unless you're a botanist doing an experiment, lol. Those gaps will settle with moisture and then open as the moisture goes.

It's one of those detail things. Thank you Thistle!!!

Yes, especially peat moss. Ever open a bag of peat moss and try to wetten it? One of those "bale" bags? Man! Extreme hydrophobic.
 

catjac1975

Garden Master
Joined
Jul 22, 2010
Messages
9,030
Reaction score
9,181
Points
397
Location
Mattapoisett, Massachusetts
I set up my plant trays with the mix dry. I wet it from the bottom of the tray and they spray the top of the mix using warm to hot water. I wait until the next day to plant. This makes the mix just right.
 

Ridgerunner

Garden Master
Joined
Mar 20, 2009
Messages
8,232
Reaction score
10,073
Points
397
Location
Southeast Louisiana Zone 9A
The other side of this is that it can be easy to get it too wet and it just won't dry out. Then you get the problem Marshall mentioned. No air around the roots. And it can lead to damping off. That can happen as the seed is sprouting, even before it breaks the surface.

I think the best solution is to try to get it wetted a day or two before you plant, something like Catjac is talking about. That requires planning ahead. Some of you may be better at that than some of us. Notice which of those groups I put you in and I put me in.

I used an old really dried out bag of peat moss as mulch for my blueberries. That has been out there since last fall. I think it has finally gotten wet throughout.
 

journey11

Garden Master
Joined
Sep 1, 2009
Messages
8,470
Reaction score
4,228
Points
397
Location
WV, Zone 6B
Ridiculously frustrating stuff to work with. :tongue :) I soak mine, putting a few inches of warm water into the bottom of my plastic tray, then setting my filled cell packs down into it and add some water from above too. Warm water seems to work better for some reason. I let it sit a whole day then let it drain for a couple hours before I set my seeds in it. Heaven forbid you forget to water your babies and let it dry out again!
 

canesisters

Garden Master
Joined
Nov 16, 2011
Messages
5,684
Reaction score
7,468
Points
377
Location
Southeast VA
I think I might be one of those 'who have had problems lately'.

I was switching some rosemary cuttings from the jar of water to little pots full of seed-starter mix (what I had handy). I filled the pots halfway with (dry) mix, held the little baby plants in place in the middle and filled in around them with more (dry) mix. Then tried to water them.... It pooled up and ran off the top. I put them in a dish of water - they floated and fell over. I ended up spending a ridiculously large amount of time dripping water into them to get them moist. Half of the babies died. But the other half are doing well - lesson learned.

Couple of weeks later. Time to start my veggie seeds and I've gotten the wonderful advise to moisten the mix before hand. As it turned out, I only had half a bag left after the rosemary fiasco - which worked out well. I dumped a couple of cups of nearly hot water in the bag and worked it into the mix throughly. * Don't know if the heat helped any but it was much nicer to handle than cold * Once I had all 72 cells of the little 'seed starter/greenhouse' loosely filled I put it away for a few days. Last night when I was starting some seeds, I used a spray bottle to mist the surface, then really squirt them good to wet them. They sucked up that water like a sponge. After planting my seeds, I misted them again.
I just checked and they are still just slightly damp.

So I agree that there is a 'something' that makes it nearly impossible to simply pour water on the dry mix and get it wet. But it seems that once it has gotten it's first good wet-down, it does well. I'll let yall know how the germination and sprouting goes.
 

April Manier

Deeply Rooted
Joined
Sep 6, 2010
Messages
592
Reaction score
5
Points
108
Location
Eugene, Oregon
To break the surface tension on dry potting media or outside soils (surface tension causes teh water to bead off) add a little dish soap to your water, mix in water thoroughly and then water in. Sometimes teh media is just too dry and a little chemistry is needed.

Also, when media is really dry, several waterings will be needed to penetrate to the bottom of pots/cell packs/ starting trays.
 

MontyJ

Deeply Rooted
Joined
Oct 26, 2012
Messages
1,815
Reaction score
527
Points
197
Location
West Virginia
I usually use Pro-mix BX as my starting and growing medium, and will do so this year as well. It also has the moistening problem, but that's not the point of this post. I was at Lowes the other day and found a bag of Burpee "Eco-friendly" Organic seed starting mix. I didn't buy it because of the Eco or organic stuff, but because it was cheap and I just needed a small bag for some herbs and test germinations. Well, this stuff is made from coconut fiber. It took water like a sponge. I was really impressed with how easy it was to moisten. The seeds are germinating in it just fine. I will still use the Pro Mix BX because I buy it in 3cu foot bales and will go through a few of those in a season.
Just thought I would share that bit about the Burpee mix, since it did take water very well.
 
Top