My advise is keep your soil mix damp, like a squeezed sponge. For Petunias or anything that is surfaced sowed and need light for best germination: If the tray is still to germinate, start with pre-moistened soil mix, bottom heat and spray the surface with camomile tea room temp (preventative for damping off disease). Check twice a day...don't want the seeds to dry out once you introduce moisture. Don't mist, you want the clay coated (pelleted) seed to find a place with good soil contact. If sowing raw seed, spray with mist...don't want it to blow out of the tray. Once germinated, keep the "damp sponge" wetness level, you will have condensation on the dome. Remove bottom heat after germination. Once they form the 2nd set of leaves, fertilize with diluted fish fertilizer once a week (spray bottle for foliage). Bottom watering is great and allow the tray to absorb the water for about 1 hour and then dump the water out of the tray. You don't want soggy soil ever. You also don't want parched conditions, so check them morning & night,

wow you keep them soaking for an hour?... doesn't get too soggy keeping it in there for that long?.. I never bottom water so I don't really get it

I always use a spray bottle to get the pellet to wear down.. seems to nestle the seed right into the soil without covering it

I never bottom water for that long. It depends on the depth of the water I think. Deeper water penetrates faster.

Karen

oops, meant to type 1/2 hour, and that is depending on how big the cells are in your tray. I sow most of my petunias into a 32 cell (2" cell that is about 3" tall), so there is a lot more soil and root space than some of the smaller 72 cell trays which are a fraction of the size for individual cell size compared to the bigger ones. I have found that the bigger cell trays way easier to take care of than the others. Biggest difference in the height of the cells. Anything less than 2" tall is very difficult to keep at a consistent moisture level.

I know you're supposed to bottom water, but I can't figure out how to do it with the number of trays I start. And if I attempt it, invariably it's in a tray that leaks!

I like that lots of people are sharing thier preferred methods. Most garden advice is just "do it this way", which I think menas "I like to do it this way", rather than "this is gthe One True Way that is best for all plants and all climates.

Key words like "greenhouse" or shelveS (plural) with flourescent light fixtureS (plural) , or sunny windowS (plural) indicate circumstances that some take for granted and others pray for.

Then there are things that many people "just know" but I've been trying to learn for years, like "JUST bottom-water",or DON'T over-water, or "damp not soggy".

And obviously the phrase ."soil mix that drains fast ENOUGH" means something totally different to me than to most people.

I'm going to toss in several posts about "my way", not assuming that "my way" is likely to be more usefull to someone else than "their way" under their circumstances. But maybe some element of something I do for one reason may be usefull to someone else when added to their methods under their circumstances.

Like the ketsup bottle, the cotton flannel, or the sharpshooter spade.

edited to add:
P.S. I see it grew into five chapters! Oh, well, you can "page down" past them pretty quickly.

Steuber
>> in Snohomish. I get a bag of redi-earth. It is just great to start seeds in. Then I go to HP for the seedlings.

Once I master the trick of screening out almost all of the pine bark FINES from mulch, there would be room in my soiless mix for some peat-based commercial mix. I'll try those two since I really hate the various other commercial mixes I've tried. Maybe a mix that had big FIBERS of sphagum peat instead of plain peat "powder" would be an improvement.

For some reason, I need MUCH faster-draining seed starting mix than most people, and prefer somewhat faster-draining potting mix.

But really, I don't want more than 10-15% "fines" in my seed-start mix until I get over my acute over-water-itis, and maybe not then.

Even in potting soil, $4 per cubic foot pine bark seems more desirable than, what, $6-10 per cubic foot peat mixes?

2.

When I start seeds indoors, I always use "cell" trays, also called "inserts", or I use a sturdier "propagation tray". Usually 50, 72 or 128 cells per 11x21" tray, because I only have room for 4-5 trays, and want to start more seeds than I have room for.

Seed starting is where I struggle hardest against overwatering, maybe because I can't believe that those shallow cells hold enough water for even a seedling.

Shallow cells are extra vulnerable to water-retaining mixes, becuase they hold an inch or two of "perched" water at the bottom of the cell, and the cells are only 2-3 inches deep total. Thus the roots can very easily be drowned in 2/3 of the soil depth. (I see Joanne
said something similar earlier.) I would love to find some 50 or 72 cell trays that were 3.5" or 4 inches deep!

Capillary mats (or cotton flannel;, or maybe rayon or cotton batting or maybe cotton denim) in the bottom of a tray help in two ways:

1.
They help suck the excess perched water out of the bottom 1-2 inches of soil. That helps roots not drown when I overwater.

2.
Also, by sharing small amounts of bottom-watering water to every cell, they help me trust that every cell is getting enough water even if I don't drown them.


That is the closest I've come to bottom-watering: last year I put cotton flanner between the trays and the inserts or propagation tray (making sure the cells sat flat on the flannel, and were not supported up off the floor by their sides.

Then I would add just enough water to the bottom of the tray that there was a tiny bit of standing water in the channels under the flannel. Then I would let the soil suck water up from the flannel by capilarity. If any visible water was still standing 30-60 minutes later, I would tip the tray and suck out excess with a trukey baster.

3.


Like sewNsow, I water seedling trays with a sprayer mist when I can't resist watering them. It keeps the surface moist without necessarily adding huge amounts of water. And sometimes I'll just spray the inner surface of the humidity dome.

A sprayer is also good when you have a overpowering yen to water seedlings that have emerged but don't yet have many roots. Less is better!

I agree with sewNsow that a turkey baster is good for watering ... IF your hand is steady.

But if you're like me and somewhat spazzy, consider saving a ketchup bottle. The small hole lets out an even finer stream of water than a turkey baster does, and lets you aim them.

I often water onto the plastic dividers and corners between cells - that way, no water splashes onto soil, it just splashes onto plastic BETWEEN cells and runs off gently onto the outer periphery of each cell.

A shakey hand is almost a benefit, since it shakes mere droplets out of the ketsup bottle.

But a turkey baster is an absolute necessity for an over-waterer, because you can pull standing water out of the trays when you over-water, either from the top or from the bottom.

I don't know any other way to prevent fertilizer salts and soil acids from building up in the tray as water drains out of cells and pots and then evaporates from the tray, leaving salty acid behind. The acid soon eats the cotton flannel to shreds!

Maybe the trick should be potting up out of the small inserts **ASAP**, instead of waiting for the roots to get extensive enough that they hold the soil ball together when I plant out. I prefer that for planting out, because you can "pop and drop" whole root balls into planting holes without the root ball tearing itself to shreds.

If seedlings never stay in trays long enough to develop root balls, they might never accumulate salts. But if I hope the plants will survive my clumsy handling, I have to pot them up while sitting down right close to the trays and pots in good light, not trying to bend over to reach ground level while the baby roots fall apart in my hand. Emphasize "trying to bend over" (With my legs, squatting isn't an option.)

(The following is mostly for very clumsy people, or if you can't squat or bend very well. Another metohd is to build tall raised beds with deep walkways (trenches) between them. Then the soil is at knee or waist level even before you try to bend.)

My best planting-out technique is to pop a solid root ball (root bound, unfortunately) out of a cell or pot and onto the tip of a "sharpshooter" or trenching spade. Then I can lower the root ball and let it slide gently into the planting hole even if the hole is in the middle of a 5 foot wide bed.

4.

I sometimes pot up from the cell trays to 3" square plastic pots, mainly when it's still too cold or wet to plant directly into the ground, or to give the seedlings more of a head start against the Slug Army. I would do more of that if I could find a place to keep MANY trays of pots - like more area indoors with light, or some kind of slug-proof outdoor cold frame.

I used to pot up from cells to trays of plastic Dixie cups or Solo cups, but they really tend to tip over (and I don't have room for them anywhere).

Inserts and propagation plugs don't seem quite deep enough, but big Solo cups seem taller than ideal. But I could get used to that if the @#$%&# things didn't tip over so much.

(P.S. you can make waterproof indoor "trays" from cardboard boxes by lining them with plastic bags. The boxes & bags can be reused almost forever, but never put a cardboard tray onto the ground in a rainy climate. They turn to mush overnight.)

5.


I grow out almost entirely in raised beds where I'm converting heavy clay & rocks into usable soil as fast as I can make or buy compost. The limiting factor is finding stuff to compost, and I do know about coffee grounds and bumming clippings from neighbors and looking for a landscape service that will give away chips & clippings (hopefully not drenched in herbicide).

But have used a few planters or big pots just to get more space where there is sun. I have to do more planting out in big pots because I'm running out of spots to build raised beds.

For some reason, I seldom overwater 3" pots and never overwater bigger pots. I guess I can believe that the roots have enough water even if I don't spray or sprinkle them too often. In fact, I have to remind myself to water EVERY planter and big pot during the dry season, and have lost some to UNDERwatering.

Since the planters and big pots have to be outdoors during some of spring and fall, they have to have VERY fast-draining potting mix to handle daily rain and occasional heavy rain..

Rick, I swear you are my twin. But I gotta get me a new turkey baster! Never thought of using one to suck up the excess water from trays! Great idea! And I think I now have a great use for those trashed Tee Shirts, hee hee! Capillary mats!

I use an old table knife to ease seedlings out of their tiny pots in those 72 cell inserts.

I keep watching Goodwill for a really cheap wet-dry vac. If I win the lottery, retire, and convert the whole house into seed-starting rooms, it's the way to scale up from the turkey baster!

But if I did that, one room would be "the mud room" for bottom-watering. The time I tried to do that in my bathtub, I plugged up the plumbing and had to get a plumber.

>> I use an old table knife to ease seedlings out of their tiny pots in those 72 cell inserts.

I know what you mean. I keep trying different silverware from Goodwill. I started with smallish paring knives, blunted and bent a little.

I think my best gadgets are little forks, in some cases with one time cut off. I bend the remaining tines so they surround and support the roots, if I try to pot up or plant out before the roots turn into solid golf balls. A triangular pattern lets me push the tines down around the periphery of the cell, and then scoop out most of the soil from the cell.

Four tines (two under and two around) support the soil better when the roots are too tiny to hold it together. This is another time Ilike big pine bark fibers (or the very biggest coir fibers) - they hold the soil together even if the root is just a single 1" thread.

But I prefer letting them get a little root bound in the 128-cell prop plugs or 72-cell inserts. Then I can pop a whole 6-pack or row of cells out, and drop them into planting holes just like planting bulbs. Pop and drop! No root damage at all. Just the growth check that comes from being root-bound.

Bent and cut-up forks are also great for mixing soil or loosening up the surface of pots - like a broadfork, but only 1" accross.

Hmmm, I have a nice little DeWalt cordless wet-dry vac that I bought specifically for cleaning up in the GH. Only holds 1/2 gal, but hmmm......

Nice! Before I started fiddling with cotton mats, I was starting to think about about a Rube Goldberg wet-vac made by running plastic tubing from one gallon jug to another, and finally leading to a vacuumn cleaner.

The mats probably saved me from electrocution or a BIG mess!

If your pots are wide and shallow like flats, you can remove perched water by tilting the flat and wicking most of the perched water away from the lowest corner.

BTW, Al (Tapla) suggested a sharp up-and-down shake of a tray to chase some of the perched water out of small pots or cells, if they are too small for tilting to help much. Drawing upon my Star Trek trivia, I dubbed that maneuver "Inertial De-Dampening".

I am a tool junkie and DeWalt makes some of the coolest cordless tool out there! I'm seriously considering getting another one of those little vacuums, too. It is so handy for little cleanups. Just waiting for a good deal to float by. Got a little cordless chain saw, too.

Hi Rick,I was going to ask you if you had gotten ideas on potting mix from Al's posts.I see in your last post you did.Just some of the terms you used(perched water) for instance.I can't swear to it but I really think this gritty mix is meant more for bonsai & potted plants that stay in the same pot for a season or two.Also probably great for large outdoor containers.I'm not knocking Al's mix. I've read many,many posts of his. I might have tried it,but some of the ingredients weren't readily available.

The method I use has a term.Topping over potting soil.Just a couple days ago I saw it described in detail in a propagation book I have. I didn't get it from any book..I used to start marigolds in a large cake pan. Being the tightwad that I am ,& only having a rather small bag of seed starter mix,I hit upon putting regular potting soil in the pan & using a ruler on edge , I made an impression in spaced rows & spooned the starter in the rows. Worked like a charm.I spaced the seeds out & grew on without transplanting. I would wait for a day that promised rain & set the plants in.the garden.

I don't know how many plants you want for your beds.Lots of times I will grow well over 100 petunias..If I'm sowing 10-15,my fav.container is a cream cheese one.I can plant 100 or more in a cottage cheese container,the short size.Why would you plant your seeds in a large divided flat? Or do you? I will plant zinnias or some large seed in a cell pack or plastic cup,sometimes. I've not had good luck with setting my seed containers in a tray of water. I find they get too wet. If the soil is just moist I wet it a bit with the baster & then put the topping on.I put the topping in a container & moisten. It is like the experienced cooks & their dough. After awhile they get the feel of it without even measuring.Finally I use the baster & carefully water until it just comes out the bottom.(After seeds are sown).

Is the atmosphere dry & temps warm ,hot, in your starting area?Is this why you feel the urge to drown your seed containers? I put mine in an east window until most seeds have popped..In these small containers I can get most ,,if not all on my heat mat.& then for a day or 2 or 3 they will be under lights.Lots of little seedlings fit nicely.Just 1 set of bulbs.

I used to use lots & lots of styro cups & large plastic cups but like you said they are so tippy. Plants do well in styro cups maybe because they are a tad warmer. I've finally gotten enough plastic pots.

Finally if you are serious about siphoning water ,get a plastic gadget used to siphon water from an aquarium.

One more thing before I go.Be careful about spraying tiny seedlings. That's a good way to get damp off.

Another thing,I admire your passion & desire to get it right!
Good luck!
sewNsow

I never use seed starting mix at all any more. I just use regular potting mix and it works great for seeds.

I'm not one to overwater. The seedling loss I've had has been for the opposite reason- letting them die of thirst. Benign neglect. That's for indoor seeds. My wintersown stuff outside tend to do much better because nature tends them for me, I don't have to do anything

Karen

Hi SewNSow!

I think Al does say that the "gritty mix" (1:1:1 ratio of bark, turface, and cherry stones) is for plants that you tend to keep in the same container for a long time, like bonsai. He recommends the 5:1:1 mix (bark, peat, perlite) for annuals and herbs. He uses very fine bark and peat for seed germination, I believe (I can't remember for sure).

For wintersowing petunias, I'm going to follow the experienced experts' advice and just use high quality bagged potting mix. :smily:

When I transfer the HOS to the hanging basket, I'm going to try the 5:1:1 mix. I'll let you all know how it goes!

sewNsow:

I don't start seeds on flats or divided flats, just "cell" inserts or propagation tray "plugs".

Yup, I got the idea of "use faster draining mixes to avoid root drowning" and "screened pine bark" from Al. Also many ideas about wicks and mats, though he usually says that well-draining mix should eliminate any need for wicks and mats.

>> Topping over potting soil

The closest I come to that is an idea I got from the square foot guru. Sometimes I make a hole for a seed about twice as deep as necessary, half-fill with vermiculite, drop the seed, and then top with more vermiculite. It does prevent crusting and sure ensures that the seed never dries out. But now I think that holds too much water, especially afetr the seed sprouts.

>> Finally I use the baster & carefully water until it just comes out the bottom.(After seeds are sown).

That's exactly my own policy for seed starting now, but I spray rather than baste, and use very open mix so that water runs out BEFORE the mix is waterlogged. Another way to say it is "there are always air spaces left at the bottom of the pot no matter how much wtaer I pour through the soil".

>> It is like the experienced cooks & their dough. After awhile they get the feel of it without even measuring.

Exactly! You "just have to know" what the correct final consistency should be, and then figure for yourslef some process that prodcues that consistently, despite irrational tendencies like overwatering, or forgetfullness.

>> Is the atmosphere dry & temps warm ,hot, in your starting area?

No, I keep my house cold and humidity is average.

>> Is this why you feel the urge to drown your seed containers?

No, I just dread seeds or roots drying out when the surface looks dry. Or, I feel like watering is the only thing I CAN do for them and hence over-interfere to their detriment. Or, it's just plain irrational.

>> Plants do well in styro cups maybe because they are a tad warmer. I've finally gotten enough plastic pots.

A nursery near me gave away their dirty pots, and at the end of the season, Home depot gave away / threw away empty pots. Mostly 3" - 3.5" square plastic pots. I stocked up for life!

>> Finally if you are serious about siphoning water ,get a plastic gadget used to siphon water from an aquarium.

I would build my own if siphoning was sufficient, but I mostly trying to get the last few ounces out along with a lot of air - not enough liquid to fill a tube and create a column of water that will siphon. A tiny wet-dry vac would be great, but a turkey baster actually handles the volume OK.

>> One more thing before I go.Be careful about spraying tiny seedlings. That's a good way to get damp off.

Yes and no, mostly yes. If the air is dry and I leave a small fan on, they dry quickly. Also, I think that washing dust and bugs and spores off occasionally is good. But you are right: anything that encourages stems and the soil surface to STAY damp encouages damping off.

One reason I like screened pine bark is that the surface dries out rather fast, and there are many big air spaces at the durface and through the soil. I haven;t lost even one seedling to damping off since I went to fast-draining pine bark, and roots happily fill the cell right down to the bottom.

>> passion & desire to get it right!

Thanks! Very gradually I am smartening up and adapting my passion from "do it my way" to "do it how the plants like it". Fortunately, even for any one given set of circumstances, there are dozens of different "ways" that leave plants happy.


Karen:

>> I'm not one to overwater. The seedling loss I've had has been for the opposite reason- letting them die of thirst. Benign neglect.

I think that is better for most seeds. For a while, I tried to curb my overwatering by changing the mantra from "moist not soggy" to "NOT TOO DRY". That helped slightly.

Then I tried to convince myself to ride as close as I could bear to letting seeds get ALMOST TOO DRY, but what can I say? That makes me feel anxious and neglectfull.

I tend to smother and over-protect when it comes to watering - like an overprotective parent driving their kids totally crazy. Too bad I can;t transfer that desire-to-meddle into a need to buy and spread "too much" compost several times per year outside. IS there any such thing as too much compost?


ssgardener:

>> He uses very fine bark and peat for seed germination, I believe (I can't remember for sure).

Yeah, but he knows how to under-water (that is to say, "water optimally"), and he gives a lot of attention - more than daily - to his potted plants, so he must really hover over seeds..

My fast-draining full-of-air-space mix is a work-around for the biggest garden pest that I can't eradicate: the nut with the watering can.

One thing to remember about fast-draining mixes in bigger containers: they DON'T hold as much water as those fine mixes. Thus a big or thirsty plant will need more-frequent waterings in a "fast" mix. A perfect combination with automatic drip watering to each pot.