Clump transplanting & Critter's seed starting tips

I keep having to retype this stuff in various places, so I figured it would be easier to find if it had a thread of its own!

I've been starting plants from seed for several years now. I get to try varieties that aren't available locally as plants, and I have fun swapping seeds so I can try other people's favorites also. I love it!

I like to start my seeds in a fairly shallow seed flat... I find that a clear plastic takeout container works great! I put holes every inch or so in both the bottom (for drainage & bottom watering) and the top (for ventillation so humidity levels don't get too high), and I put about an inch of well moistened potting mix into the bottom. I start with a basic soil-less mix like Pro Mix, and I lighten it with a little extra perlite and add polymer moisture crystals to make to help me keep the moisture levels "just right." I sow seeds fairly thickly, in rows about an inch apart. When seedlings start to get their first set of true leaves (the first pair are cotyledons), and for sure by the time they get their second pair of true leaves, I transplant to 2 inch pots or cell packs. The smallest pots I use for seedlings are usually the 48 cell sheet pots that fit a standard 1020 nursery flat, and I like the 32 or 36 cell flats (the equivalent of 2 inch pots) for tomato & pepper seedlings.

I've been planting basil and some other things (alyssum, lobelia, dill, parsley) in clumps for several years now, following the directions Tom DeBaggio sets out in his "little book" (_Growing Herbs from Seed, Cutting & Root: An adventure in small miracles_), and I've had great success. He's a fan of clump transplanting for several reasons. A larger clump of roots in the pot means it's harder to drown the little seedlings (root & stem rot are less likely when the roots take up more water and accelerate the drying of the growing medium), and you get a nice branched appearance before you even start pinching back. Tom recommends 3 or more plants in a clump (my clumps max out around 7, and some of those basil varieties just got clumped by twos last year). In his words, "I don't count them, but take what comes apart most easily with the least root damage. It would defeat the beneficial effects.... to prick out individual seedlings and gather them in clumps.... the larger the leaves, the fewer seedlings in the clump." The other big thing is to set the seedlings into the pot lower than they were growing in the seedling flat, preferably (depth of pot permitting) with the true leaves level with the growing medium and the nurse leaves (cotyledons) covered.

Although I have never (knock on wood) had trouble with damping off, I do take a couple of precautions now. I sterilize my seed starting mix. Some people do this in the oven, but I think it is easier to do in the microwave, in my very huge tupperware bowl that holds about a gallon of mix. Moisten the mix well with 1 to 2 cups of water per gallon (or your potting mix will catch fire, and I am not kidding), and cover loosely (don't seal the lid). Microwave on high 12 to 15 minutes, until you see lots of steam condensing on the underside of the lid. Seal the lid, and allow the steam to continue sterilizing the potting mix another 15 minutes or so, then cool. An added benefit is that the steam does a really good job of "opening up" the peat moss so it gets nice and moist and will absorb water readily. Additionally, I water seedlings with either diluted chamomile tea (1 teabag for a gallon) or peroxide water (1 Tbsp. of 3% hydrogen peroxide per quart of water) to guard against fungus etc.

I like to use the 1020 nursery flats (those 2 inch deep black plastic trays) for seedlings, because I think bottom watering is easier & better for the seedlings (the more moist the surface of the soil, the more likely to have algae or fungus growing in your pots). I pour 1/4 inch to 1 inch of water into the flat (depending on the size of the pots & on how dry the potting mix has become), and if any significant amount of water remains after 15 or 20 minutes, I pour it off rather than letting the plants sit in a puddle. Since I'm using the polymer moisture crystals, actively growing seedlings generally need to be watered every 2-3 days.... covered seedling flats need watering much less often; as long as you see a little mist of condensation on the inside of the cover, the seedling flat is sufficiently moist.

I did get seedling heat mats and a thermostat last year, and I love them. My pepper seedlings did very well last year, and any seeds that like a warm start germinated much more quickly. I set my thermostat at 78 to 80 degrees. For safely reasons, *please* do not use an old electric blanket or heating pad under your seedling flats, as that violates a whole bunch of manufacturer's warnings. There are inexpensive alternative such as making a light box (enclosing your seedling area and heating it with a 40 watt bulb or two connected to a thermostat switch).

I should also mention lights... Even the brightest windowsill has a lot less light than a sunny spot outside, and seedlings grown in natural light will tend to be leggy at best. You don't need to invest in anything fancy.... a regular shop light and inexpensive cool florescent bulbs work just fine for seedlings. It's best to devise a way to raise and lower your lights so you can keep the bulb just a couple of inches above the top leaves of your seedlings. A 4 foot shoplight with two 40 watt florescent bulbs (or two 32 watt T-8 bulbs) will provide enough light for two 1020 nursery flats of seedlings.

That's all that I can think of at the moment! I'll add comments & do my best to answer any questions, and I'll try to add some photos also when I get back to the other computer.

Here's a link to one of my favorite threads, Carolyn's method of starting tomatoes from seed: http://davesgarden.com/forums/t/490323/

I used her method last year and had my sturdiest tomato seedlings and best crop ever! :-)

Critter
I would love to see this information that was posted in the herb forum by the same title made into a sticky for newby herb gardeners. This is wonderful info and sure would have helped me out a lot when I was knew to DG. I have noticed sticky's are being placed with valuable info at the beginning of many forums and refer back to the info often. :)
... Elaine

Quyen's recent Dmail reminded me I wrote out some additional information on starting peppers from seed that's pretty well hidden in an old thread on the pepper forum. Some of it repeats what's been written above, but I figured it was best to just copy & paste the whole thing here:

Soak pepper seeds in warm, half strength chamomile tea for at least one hour. Some chile seeds that I soaked for 8 hours germinated very quickly for me. When they sink, they have soaked up all the water they're able to absorb.

Put about 1 inch of moistened, sterilized potting mix (with a little extra perlite) into the bottom of a seed starting tray. I use clear plastic take-out containers for starting seeds, and I put a bunch of small holes in both the top and the bottom of the container using a metal skewer heated on the stove. Some folks use an old soldering iron tip for this... melting holes in plastic often works better than cutting them.

Even seed starting mixes out of a fresh bag aren't really sterile... I put my well moistened potting mix in a big tupperware container with the lid on loosely. Microwave on high for at least 12 minutes (until you see steam forming and condensing on the inside of the lid), then put the lid on tightly so the steam sterilizes the mix. There are other methods, but the steam does a nice job of wetting through even very dry peat moss.

Use a pencil held flat, or just use your finger, to press a shallow furrow into the potting mix for your seeds. Make your rows (furrows) about 1 inch apart. Sow seeds 1/4 to 1/2 inch apart, pressing them down lightly and barely covering them with moist potting mix.

Pepper seeds like warmth to germinate, and bottom heat seems to be best. There are many ways of achieving this, but my seed starting trays are on 80 degree heat mats this year, and the sprouts just leap up in record time!

After the peppers begin to germinate, put them under florescent lights, with the tubes not more than 2 inches above the seedlings. Make sure there are ventillation holes in the cover of your tray, or prop the lid open slightly to reduce the humidity a little. The lights will help your seedlings grow stocky & strong.

When the pepper seedlings have 1 to 2 pairs of "true" leaves (the first pair you see are nurse leaves, or cotyledons), it is time to transplant them. 2 inch nursery pots or something similar in size seem to work fine. Fill the pots with moist potting mix and tamp the mix down lightly.

The roots of your seedlings may have grown together in the row; this is fine, and it will make them easy to handle. Handle seedlings by their rootballs (if they have a clump of soil; try not to touch delicate bare roots) or by gently grasping the leaf tuft. The stems are very tender and easily damaged at this point, so don't pick them up by the stem.

Break out a row of seedlings from the starting tray, and gently separate the row into individual seedlings, trying to keep as much soil around the roots of the seedlings as possible.

With a stick or with your finger, make a hole in the center of the potting mix in the pot. The hole should be wide enough to accept the rootball of the seedling, and as deep as possible. You want to set the seedling deeper than it was growing in its seed flat. It's fine if the nurse leaves get covered by the potting mix, but the first pair of true leaves should be a little above the soil level.

Gently firm the soil down around the seedling, and water it in to settle the soil around the roots. I'll be using weak chamomile tea for this intial watering, too, although I've just used plain water in the past. You can also use hydrogen peroxide water to guard against damping off & other problems; add 1 tablespoon of 3% hydrogen peroxide (household strength) per quart of water.

Put the seedlings back under the lights, adjusting the height of the lights as the plants grow. I'm debating whether it might be better to grow them on at my normal 60-70 degree basement temperature or to continue setting them on the heat mats....

I like to bottom water by putting half an inch or so (more as the plants grow) of water into the bottom of the flat and letting the potting mix wick it up. Check to be sure there isn't water sitting in the flat after 20 minutes, as you don't want to drown your seedlings. Water when the potting mix seems dry to the touch (generally every 2 days for me, but the plants' needs can vary).

This year, I'm not adding fertilizer to the water since my potting soil has some added fertilizer already. Last year, I watered with about half strength Miracle Gro when the seedlings had 2 pairs of true leaves.

Harden off and plant out after all danger of frost, generally 2 or 3 weeks after you would put out tomatoes. I like to add slow release fertilizer to the planting hole, and those moisture crystals are also very helpful, especially if you're planting in containers.

I hope that summary was helpful! I didn't describe the process of hardening off, as I'm sure that's well covered elsewhere.

This message was edited Aug 23, 2006 3:45 PM

This message was edited Mar 6, 2008 1:54 PM

Critter, lots of wonderful info. They should all go to a sticky.

How long do you keep the seedlings under lights?

Critter thanks!

How long they stay under lights depends on the seedling type. Seed packets often have suggestions, "Start indoors 8 weeks before last frost." I generally start tomatoes 6 to 8 weeks ahead, following Carolyn's method (see link in tomato forum sticky). Peppers get a good 10 week head start, as do Torenia, Impatiens, and a couple other slow-starting annuals. Other annuals get just 4-6 weeks under the lights, and if I start cucumbers and the like indoors I give them only 2 weeks before setting out (they are fast growers, and their roots do not like to be confined).

I guess I should Dmail Terry and see about getting this thread and maybe the one I posted about cuttings put in a sticky on the propagation forum... Thanks! :-)

Thank you, Critter. This is good info, especially for starting those tricky/hard to germinate seeds.

Critter, Your instructions from July 18 are missing the number of minutes to microwave the potting soil:

....Microwave on high for at least minutes, ......

Hellllpp.

Tks.

I sterilize my moist potting mix using a turkey-size oven roasting bag, for 10 minutes on high in the microwave. The temperature rises to well over 212 degrees. The reusable bag or Tupperware bowl prevents the mix from catching fire (what a mess!).

oops, sorry, I edited to fix that. I do mine at least 12 minutes on high.

Make sure you moisten the mix well... I add at least a quart of water to my bowl, which I think holds between 1 and 2 gallons of dry mix. See this thread for what happens if you try to sterilize dry mix, http://davesgarden.com/forums/t/485684/

I've been linking folks to this thread more often recently, so I thought I'd give it a bump for those souls lucky enough to be in warmer zones where it's already time to start seeds!

Very useful thread, critter! Just in time, too.

Wonderful, Jill - thank you. There's a couple of spots needing this link. I do wish this thread could be kept via sticky at the top of this forum, too.

Critter, I'm copying your post for reference into my diary. I seem to always loose information sources. I would hope DG makes this info available in a sticky.

I just love the book Critter...Growing Herbs from seed, cutting & root well worth what I paid and them some, thanks for the heads up on it.

Hopefully DG will make a sticky of this info.I have learned sooo much.Thanks for the easy to understand instructions Critter.Even I should be able to do well now : )
Nancy

I'm glad it was useful, and I'm glad other folks have been discovering Tom's wonderful book!

I just sent a note to admin (to Terry) asking about making a "sticky" thread of useful links for the propagation forum as has been done on other forums (tomato forum, for example). I think there are other threads that get referenced a lot, and it would be great to have them all easy to find. Please keep a lookout in case Terry posts a thread for suggestions, and dig up some good threads on other topics that come up a lot (DIY plant stands, grow light alternatives, etc)... hopefully we'll get a sticky!

Howdy Jill ..

An extraordinary wealth of info, that you've been sharing with all of us. Tis much appreciated, for sure ..

*I* think, that you oughta write these up as an article for 'web publishing' on the Articles on Gardens.com.

Go to the DavesGarden forum, and look on the list of threads, for the one titled: Articles on Gardens.com .. to see those that many folks have already contributed! THIS .. would fit in perfectly, to boot!!

((huggs))

- Magpye

This message was edited Feb 15, 2007 11:02 PM

Magpye, Ithanks! I've thought about doing a seed starting article... I think it would be OK to use Tom DeBaggio's description of clump transplanting as long as I gave credit (and maybe a Garden Bookworm link)... I'm catching up on a bunch of stuff right now but will try to get on it so folks have the information in a timely fashion (and yes I know that it's already seed starting time down south, but as I said, I'm playing catch up!).... we'll see how it goes!

Hi Critter,
thanks for the post. I hope you don't mind if I link it to my journal "Off the Shelf Garden tips H202/Aspirin and ....."
http://davesgarden.com/journal/ed/index.php?tabid=1923

I believe the H202 has something to do with preventing damping off. Is there a location you keep your seedlings? I noticed your tip about putting them outside. When you do, do you open the lid, or are the vents enough.

I'm getting ready to gear up..the thermostats..can I buy those at home depot? I have 2 matts, and I need to wire them up this weekend, and prefere to do thermostats...I don't even know what it looks like.

Thanks!!
Rj

The thermostat I use with my seedling heat mats was purchased with them. Please get some advice about wiring one in... you don't want to just cobble something together with electricity and hope it works.... while it's certainly a reasonable DIY project if you know what you're doing (and I'm not saying that you don't), you can run into safety and fire hazard issues, so please be careful.

Yes, the hydrogen peroxide or chamomile tea added to the water is meant to prevent damping off.

My seedlings are on shelves in the basement, with florescent lights (4 40 watt T-12 tubes over 4 flats of seedlings) that can be adjusted in height (ideally, you want the lights just an inch or so above the top leaves of the seedlings. The vented covers on the flats are really just for germination and very young seedlings... when I pot them up into sheet pots (aka, those nursery 6-pack 36 or 48 cell inserts), they no longer have a cover, and so they are not covered like that when I start hardening them off.

I agree.. I am not fond of electric current, and less fond of working with it. I am taking it to a friend who is more apt at it than I.

Good! :-) That's the kind of project that's simple if you know what you're doing, but can be disastrous if you try to wing it.

Your right... I keep my experimenting to growing things, and relatively minor consequences. So you don't think the pet mats would be good to hook up to a thermometer? I've never even heard of anyone using these for their pets..have you?

I think that, IF properly wired to a thermostat, the pet mats should work OK... presumably they (unlike electric blankets or household heating pads) are designed to use under things, and presumably they are moisture-proof... read the multitude of warnings that doubtless came with it, and you should be able to make the call.... I always err on the side of caution with electricity.

There was a recent thread about heating mat alternatives, and somebody posted directions for using rope lights in a sand (or kitty litter) bed under propagation flats.... that's the kind of info we need to have links to in a sticky! :-) Speaking of which, I got email from Terry... she thinks it would be great to have a sticky thread for propagation info, and she said she'll see what she can do.... isn't she a gem??

Yes...!
Do you have a web site with the plant mats..I would like to check the watts.
These matts look pretty durable, but have nothing but pictures to compare them too. One would think they are water proof, if they are used for pets... spilled water...bladder accidents..
Here are some photos. Hope you don't mind...

side view...they are 200 watts though..that seems like alot..but I know nothing except 50 and 100 watt light bulbs.

very flat

I got my seedling heat mats and thermostat from Park's. http://www.parkseed.com/webapp/wcs/stores/servlet/StoreCatalogDisplay?storeId=10101&catalogId=10101&langId=-1&mainPage=prod2working&ItemId=96067&PrevMainPage=textsearchresults&scChannel=Text%20Search&SearchText=heat%20mat&OfferCode=T1H


The watts on my mats doesn't matter... just be sure that the thermostat you get will work with the wattage of your pet mats.

Okay..thanks...
It would seem that that mats are of similar construction, but then that's an obscured picture. The Thermostat is cool, but I couldn't find much data. I think I may consult my favorite local garden shop that has everything ! I will check around some more on the thermostats.. I definately would like to have that control..

I decided I needed a thermostat on my seedling heat mats because they generally heat the pots to 10-15 degrees above ambient temperature... on crazy-warm winter days, it can be over 70 degrees in the basement, and I think temperatures over 84 or 85 have been said to kill seeds, so I didn't want to take a chance on overheating my flats.

okay...I've been looking all over home depot for stuff...found some close things..but the one said 110V and this mat sas 200V..
I am going to use it in the green house ...it will be outside.

Even outside, you don't want an electrical fire... make sure you get a thermostat that's rated for 200V. :-)

HAPPY BIRTHDAY CRITTER!!!!!!!!!!!!!!! :) Your such a wealth of info! Thanks!! :)

Susan

oh weird..was just wondering how you were doing Susan...
rj

Happy Birthday Critter ..

Critter, Thanks for the information - I may have to give this seed thing a try during the winter. My hobby is propagating woody southern plants. The seeds would give me more color in my container gardening. Happy Birthday, and do be presidential! Good gardening.
Ray

hey RJ... I'm really wanting to get outside and garden already.. it's too cold for my liking.. 43 right now.. I'd like 60 :( Oh well... gardeners are tough!! :)

Susan

I just got out this weekend..had a hard freeze last week, and I'm doing clean up. Warm weather probably headed your way..

I appreciate the birthday wishes! And while I don't normally mind O/T chatter a bit, I'd like to try to keep this thread a little more focused on seed starting since we've been talking about linking it to a "sticky"... it'd be better not to have lots of extraneous posts, I think. Thanks! :-)