Potting soil

[Daylilyfanatic4]

Potting soil is getting expensive around here and I was hoping to mix my own this year to save $$. I figure a 60/40 blend of peat to compost would work. I can get a couple bales of peat moss but I'm wondering what to do about the compost part. The town supplies free weed free compost every year for free but it has to many undecomposed woodchips to be useful in containers. I do make my own compost but not a nearly enoguh. The easiest source for me would be lowes but I'm having trouble finding any good quality brands of just plain compost (not potting soil). Anyone have suggestions of what to look for?

According to the Lowes website this Mushroom Compost is avaliable at my local store but the "high water holding capacity" advertised worries me. I'm afraid it won't drain well and I'll end up with a soggy mess.

There is also Scotts Brand soil. Has anyone ever tried these products? Do you think they'd work? I'm looking to fill 9 10 gallon grow bags and 8 9 quart pots how much soil would I need if I get two bags of 3cu foot peat moss. So probably a total of 12 cubic feet when it is loose.

I need to fill 108 gallons of soil the peat moss should be approximetly 89 gallons if my calculations are corect which means how many bags of potting soil?

Thanks for the help.

[ExpendableZero]

I haven't found a container yet that can actually hold the advertised gallons. I bought a lot of peat moss and compost. I will just fill bags until I run out. The rest will be given away.

I get nearly all my bagged soils at Lowe's- they price broken bags at 50% and that's when I stock up! I check every time I am there. That's about all I have in my gardens.

[Skaggydog]

Originally Posted by ExpendableZero

...I bought a lot of peat moss and compost. I will just fill bags until I run out. The rest will be given away.

I can give away vegetables, but NEVER compost!

[ExpendableZero]

Sorry, I meant until I run out of compost and peat moss. I ordered more bags than I will ever use.

[willyb]

Hi,

I share your feeling about buying potting soil in a bag. There is no need to buy soil from another state/province when a local source is available. Your local free compost sounds good to me! I don't see undecomposed woodchips as a problem. It will rob some nitrogen from the soil, but tomatoes don't need much, without it they will produce less foliage and more fruit.

I get Spent Mushroom Compost for $15 an overflowing pick-up truck load and use lots of it. It does compact if you walk on it every day. It is fine in a container. Not to worry about too wet. In a fabric bag it will evaporate and your plants will love it.

I mix my SMC with 3/8 rock, works like perolite and adds minerals over the years.

If I was in your place, I would use the free topsoil. Add some perolite, rock or vermiculite for drainage. Add some bone meal and grow tomatoes like crazy.

I trust your sewing your own grow bags? Use cheap landscape fabric. All the same. Cost is less than 50 cents a 10 gallon bag.

Cheers,

Brad

[janezee]

Thanks for the tips, Brad.
You sure are lucky to get your mushroom compost at such a good price. I get it at $27, plus state tax that brings it to $29.34, and I considered it the bargain of the century. I buy a truckload once a month for 6 months out of the year. Best stuff since I gardened on a former cranberry bog, with gorgeous black topsoil 18" deep. Heaven!
j

[Daylilyfanatic4]

I used the free stuff last year and it was a disaster in my containers. Even mixed with peat moss it was still to heavy and didn't drain well enough. I'll continue to use it for my in ground plants but I know I need a looser soil. It is just a question of what exactly is the best option. Also unfortunately my grow bags are plastic.

[willyb]

Too bad about the free compost. Would it be possible to risk one or two plants with it again this year in a cheap fabric bag. I am not a fan of plastic for grow pots, even if they have drainage holes in the bottom. I doesn't breath to allow air to the roots and it keeps any soil too wet if over watered.

I do grow some tomatoes in 5 gallon plastic buckets. I drill holes around the perimeter 10" from the bottom for air and water overflow (a 3/8" hole every 2 inch's), none in the bottom. Fill with coarse rock and rubble to the drain holes level. Fill to near top with an amended mushroom manure. Water until it overflows out the drainage/air holes. I water once per week. The water wicks up through the strata just fine and the soil stays evenly moist.

[willyb]

J,

Your right that your $30 mushroom is a bargain. I think far too many Gardner's buy soil and amendments in bags for too high a price, much that is shipped from coast to coast. Think of the waste of fuel.

Your lucky to be able to garden on the north west coast, I used to envy my old uncle's climate near you on Camino Island. He used to gather sea weed and all the flotsam that came with it to mulch his tomatoes. The salt didn't seem to bother them.

Brad

[dice]

You could check local landscape materials supply companies for lava
rock, pumice, or "decomposed granite" (granite dust and gravel from
quarries) to mix into your peat. (You would probably need to add a
handful of dolomite lime per container for a source of calcium and
magnesium and to raise the pH of the peat from the around pH 5 range
up to between pH 6 and 7.)

An alternative would be to mix bark fines into it (pine or fir bark, shredded
as fine as you can find). Bark is somewhat hydrophylic (repels water) and
adds air space without adding much weight.