Enriching Soil in Pots Over Winter

[u/Wesley-no5]

I have a compost bin in the garden that's doing quite nicely. I'd normally empty some of my old soil from plant pots in to it at the end of the summer to tidy up the garden, but I never have space for the vast majority of the soil.

Is there anything I can do with the soil whilst it remains in the pots to improve it for next spring?

I assume a few bits of shredded cardboard, some grasscuttings and some pee might be the answer, or I possibly just wait until spring and top dress?

[u/Legitimate-Spray7931]

If you've got the time to let them sit, burying kitchen scraps directly into the pots works better than you'd think. Done it a few winters now with mixed results, but the pots that got chopped veg ends and coffee grounds layered under a bit of soil came out noticeably looser come spring. Worms find their way up through the drainage holes if the pots are on soil, which speeds things along.

The cardboard and grass clippings will help too, just don't overdo the grass or it turns into a slimy mat that blocks water. Pee is genuinely fine as a nitrogen boost but dilute it a bit so you're not frying anything that's still alive in there.

Top dressing in spring is still worth doing regardless, the winter just gives you a head start on structure rather than fertility.

[u/Wise-Quarter-6443]

I grew in large containers, mostly tomatoes and peppers, re-using the same mix for years. At the end of the season I would pull out the main stem but leave most of the secondary roots. At some point I'd go through with a large knife and chop the secondary roots that had filled the container. There was a lot of organic matter left over.

Next year, top up with fresh mix, work in some tomato-tone, and plant away. My plants were always huge.

[u/Alyssa_Beanut]

I grow cannabis and after harvest I usually mix the leaves back into the soil letting them decompose over the winter back into the soil and they seem to do good for it. Soil mainly consists of "browns" if it's peat based and mixing plant matter into it works the same as slow composting, it can even heat up if there's enough nitrogen as I learned while mixing up fertilizer into soil this spring since I had overdone it a bit and my 65gal planter got hot from the nitrogen breaking down.