It is perfectly safe. As soon as it is spread out in the air the smell will go.

Oh great! Well now I feel silly 😅 I just worried I had killed all the good bacteria and created something toxic! I am relieved its safe!

Not so fast - composting that occurs in the absence of air (anaerobic) can seriously lower the pH of compost due to the organic acids that occur under those conditions. That's why leaves/ lawn clippings and chipped pine bark destined for horticultural applications should be wind-rowed and turned regularly to keep the pH within a reasonable range. If you're going to spread it as a top-dressing, it's not likely much of a risk, but it should be flushed if you plan on incorporating it around roots or using it in a container substrate (the later application [container substrate] is not a great idea regardless of the pH issues).

Al

@tapla (mid-Michigan, USDA z5b-6a)

Hi friend, sorry just saw your reply. I was worried about it being anaerobic. My soil is high alkaline if that helps?

Would it be okay if I amended a garden bed with it now in fall and didn’t plant my rose in it until spring?

I’m double digging where I removed the bottom layer and then amended with the compost and the top layer of soil.

Would it be okay if I amended a garden bed with it now in fall and didn’t plant my rose in it until spring? Yes - great. No matter how high the pH of the compost, the disparity in bulk density between the compost and the mineral soil highly favors the buffering capacity of the mineral soil, especially in view of the length of time we're talking about.

Best Luck!!

Al

OP wrote they bought compost and stored it..... so it was already composted material if I'm reading that correctly. Should be fine, albeit possibly missing it's beneficial citizens due to the storage. Like already said, the smell will go once you spread it out. You may want to test it - pH and such, before using on your roses (just in case). Or, perhaps you can dump it into your compost bins and let nature re-invigorate/restore the natural bacteria, worms and mycorrhizal fungi? I think that's what I would do.

Just refining what Kimberly wrote. Aerate it, then instead of using it on anything, mix it as an ingredient into the other compost ingredients.

Yup yup... what @four (9B near 9A) said!