I had compost in my potting mix for two years. The first year, it was sunny and warm in the spring, and everything was a big success. Then the next spring was cold and cloudy, and I got a massive outbreak of damping off. The first year, I didn't lose a single plant to it, but this past spring, I lost flat after flat of seedlings.

I wish everyone the best of luck with whatever method they use, but I certainly learned my lesson. No more compost for me in a mix, ever. I am going to buy a pallet of Fafard's mix and just use that. It is mostly pine bark fines. None of the "pro" mixes that I see have compost in them. After last spring, I think I know why.

I've always made my own potting soil, for germinating and for growing on. It's made with 6-8 parts sifted compost, 2-3 parts sifted peat and 1 part sand.
The compost is mostly manure and veg residue, aged for at least 9 months. Lately i've been using rabbit manure from someone nearby which seems to work the best. I grow fantastic starts with no extra fertilizer. My soil costs for an entire year is about $40.

In late winter when I start my cucs for planting in the greenhouse i've had problems with them dampening off like Cole robbie mentions. I started sterilizing enough soil just for them and no longer have any problems. Other seedlings that are susceptible (basil especially) i'm just sure not to overwater.

I think the biggest issues of using homemade compost for seedlings are the weed seeds and herbicides (like clopyralid) that people use in their pastures.

-Mark

This post was edited by madroneb on Fri, Sep 27, 13 at 23:54

i use screened compost (horse manure, chicken litter, garden wastes)in my potting soil. i add peat moss, top soil, perlite and vermiculite (cheaper if you buy big bags).

Thanks for the comments and recipe ideas, I have used compost to some degrees mentioned but never as the main ingredient except for perhaps some melons and pumpkins a few years ago.

I'll try some of the ratios of ingredients mentioned.
Dampening off has not been a big problem here.

I know it's not compost based but if you use premix pgx with bio fungicide you won't even know what damping off is...then you can transplant to whatever you want and you'll have no problems.

I will never again use a homemade compost mix. It gets dry and hard and weedy. I resorted to using it as the bottom of 4 inch pots for seedlings and topping with seed starting mix to prevent weeds. So I save the compost for in the garden and maybe a filler in large pots.

Minnie, seems like we make very different compost as i've never had those problems. A few weeds pop up but only take a few seconds to pull (per flat) and rather than hard/dry, the compost stays a little too wet unless I add peat and sand.

-Mark

I will say it looked great in the pots after weeding and felt good to say it was homemade compost to the customers.

i've ended up with compost behaving like yours little mini, but its because it was very wet when i used it and i packed it into plastic pots and didn't mix it with anything.