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Homemade tomato transplanting soil mix?

Posted by schroedpot 6 (My Page) on
Thu, Jan 9, 14 at 20:05

I did spend about an hour searching the forums for this without much luck...

I've been gardening for nigh onto 40 years, but now that I'm retired I decided to spend time really learning. I've always started my tomato seedlings in a sterile mix and then transplanted them to larger containers using commercial potting mix with pretty good results.

My question is: do any of you make your own potting mix for tomatoes? Have you had especially good or bad results?

Follow-Up Postings:

RE: Homemade tomato transplanting soil mix?

I planted a couple of dozen dwarf and small tomato varieties in containers in 2012, and used (more or less) Al's 5-1-1 mix.

I couldn't find actual pine bark fines, so for the 5 parts bark fines I used a mixture of mostly larger pine bark pieces and Sta-Green potting mix (about 3 1/2 bark and 1 1/2 potting mix).

I measured the ingredients with a scoop made from a 1/2 gallon milk jug with the bottom cut out, so one part was a little less than half a gallon, and one recipe was somewhere between 3 and 3 1/2 gallons.

To each batch I added maybe 1/3 cup of garden lime and a slightly larger amount of fertilizer granules.

I fertilized with standard Miracle Grow a few times.

The plants were happy till the Late Blight hit.

In 2013, I topped up the two front porch pots and planted New Big Dwarfs in them again (kind of like having small topiary evergreens on your front porch, no?). They were happy until the Late Blight....

RE: Homemade tomato transplanting soil mix?

Commercial potting mix is good too. But to me it has 2 drawbacks: ONE, it is expensive , TWO it retains too much moisture.
So I have been studying also 511 mix.(5 parts fine pine bark, 1 part peat moss, 1 part perlite) You can violate that proportion. For example make it 4-2-1- . You may also eliminate perlite (because of cost) That is what I am going to do it.

I buy 1.5 cf of bark for about $4.50 A bundle of peat poss (2.5 cf) $11.0 . So wit 5 bags of pine bark and one bundle of peat moss ( TOTAL COST = $33.O ) I will have 10 cubic foot of podding mix. It can go a long way. That is about 75 gallons.

I will use that both fore transplant and the final growing pots

RE: Homemade tomato transplanting soil mix?

Thanks, seysonn and missing the obvious!

I assume the fine pine bark comes bagged like potting soil at hardware stores and the like?

RE: Homemade tomato transplanting soil mix?

IIRC, the important thing is that it's bark (as opposed to chopped up wood). And that it's pine or fir bark as opposed to other types of bark. And you want small pieces.

You may get lucky and find a bag of bark mulch at your local nursery or BBS which fits this description. Or an expensive way to get the small pieces is to buy Repti-Bark at a pet store. Or use the small pieces in the mix and throw the larger pieces in a bed which needs mulch.

See the Container forum for more info.

RE: Homemade tomato transplanting soil mix?

FYI -- the big box stores sell suitable pine bark mulch for about $3 a bag. Not sure the exact volume, but it would be big enough to augment a 20 gallon tub, for example.

RE: Homemade tomato transplanting soil mix?

  • Posted by digdirt 6b-7a North AR (My Page) on
    Fri, Jan 10, 14 at 13:51

Since you will be growing in containers then I agree with missingtheobvious that you really need to do some reading over on the Container gardening forum. They have great discussions there about several different make-it-yourself container mixes. Al's 5-1-1 mix gets rave reviews from most all users.

And you don't mention the size of your containers. That factor is at least as important as the mix you put into them. :)


RE: Homemade tomato transplanting soil mix?

Missingtheobvious said it all. Also as Dave mentioned, visit "Container Gardening" forum and educate yourself. That is what I have been doing.

For small transplant pots ( 3" round or square, or 6") I personally use a little less bark and instead a bit more perlite and peat moss. But for the final container ( 2 , 4, 5, .. gallon pots basically the 511 will do.

RE: Homemade tomato transplanting soil mix?

Here is another option for you - it has worked for us - although I know there are many recipes that may work just as well or better.
Recipe for planting seeds:
1 - gallon coco peat (Coir)
1/4 - gallon well composted fine compost
1/4 - cup colloidal phosphate
1/4 - cup glacial rock dust (Azomite)
1/4 - cup greensand

We use the green mixing tray in the photo to mix our seed planting soil mixture.

Container soil recipe:
1 - cup blood meal or cotton seed meal
1 - cup colloidal phosphate
1 - cup greensand
1 - cup glacial rock dust (Azomite)
4 - #10 cans of peat moss
4 - #10 cans of coco peat (Coir)
3 - #10 cans of vermiculite
2 - #10 cans of clean excellent garden soil
3 - #10 cans of compost

We mix the container soil recipe in our electric cement mixer - much easier - then scoop it as needed out of the cement mixer. We developed our recipe from viewing many options on the internet. We use Azomite because it mined close by in central Utah. There are many substitutes for the ingredients and one just has to find what is readily available in your area.

We have found that mixing our own potting/container soil does save money if the ingredients are available in your area without paying freight costs to ship it in. It does require some storage space however to stack the bags of peat moss, coir, vermiculite, etc. - mixing our own
potting/container soil works for us.

 photo image_zpsc833ec2b.jpg

RE: Homemade tomato transplanting soil mix?

You have a nice recipe' there. Especially, I like incorporating garden soil and compost. But I am not very sure on VERMICULITE. I would rather use PERLITE in its place, in half the amount (5 cups instead of 10). I think vermiculite breaks down (physically) and gets compacted whereas perlite is more stable and can aide drainage better.

Just My Opinion

RE: Homemade tomato transplanting soil mix?

My homemade seed start mix is 1 part perlite, 2 parts worm castings, 2 parts peat moss. Mix well, then steam sterilize. Since I am working with bulk quantities, I mix 10 gallons of perlite, 20 gallons of worm castings, and 20 gallons of peat moss. Put the mix in a modified 55 gallon drum that has a sheet of perforated metal in the bottom with about 5 gallons of water, then place on a turkey fryer and steam the water through the mix to sterilize it. This makes enough mix to fill up 80 to 90 standard nursery trays.

I tried this mix without sterilizing last year and lost several thousand seedlings. After steam sterilizing, I produced the prettiest seedlings I've ever grown.

A google search will turn up several worm casting suppliers.

RE: Homemade tomato transplanting soil mix?

Good point - I think vermiculite works better for a seedling planting medium (when added to soil for 2" & 4" pots) with it's moisture retention abilities where perlite works better in raised beds/containers where compaction and drainage issues become important. Plus, I don't know about your area but perlite in my market area is almost 1/2 the cost of vermiculite! That is a huge difference! Even though I didn't mention that in my container/raised bed formula above - I do use perlite in all mixtures except seedlings where I still use vermiculite (that is in 2" & 4" pots - I don't use either in 3/4" seed starting cubes).

When we built our GH and raised beds 5 years ago we only used vermiculite in all of our soil mixtures and haven't changed our formula descriptions. Since then - we have discovered what you already knew - that perlite is much cheaper and better suited for drainage and aeration - IMO.

We have not had a sterilization problem in our small GH seedling soil mixture quantities as Fusion_power has experienced. We have a very high % of germination success. I can definitely see the need for a sterilization program in a large or commercial setting though!

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