I have a container and I plan to grow lemongrass in it. I don't have any potting soil left and I only have compost on hand. Can I grow plants/veggies in just compost or I have to have 50-50 soil and compost? Thanks

I plant in straight compost all the time...
Have you ever noticed all the seedlings that come up in the compost pile... how well they do when allowed to grow there?

Of course, it may depend on the maturity of the compost, homemade or store bought... other things like that...

agreed, could go well, could go bad, too many variables for us to say. (drainage being a big one)

Agree with both above, depends on the nature of the product. Some bagged "compost" is just wood chips. However, lemongrass isn't terribly fussy. Make sure you add nitrogen fertilizer in some form and it'll probably be fine. Could be fantastic!

My compost is STA Certified by the U.S. Compost Council as compost derived from curbside residential green waste. The county gives it out for free to its residents. They claim it's 100% organic.

https://www.compostingcouncil....

Still can't positively predict results but it looks promising. Will require fertilizer.

I've seen some pretty gigantic, healthy squash and tomato plants (and other more weedy things) that were either planted in a compost heap or germinated there naturally.

Compost in a pile at the edge of the garden or out-of-the-way spot on the ground is far better at supporting growth than the same compost in a container. Compost is VERY water-retentive in a container - even when mixed 50/50 with perlite. Excessive water retention of compost in a pile on the ground is largely eliminated due to the wicking ability of the mineral soil beneath the pile.

The size of particles that make up a soil or grow medium is largely what drives water retention, so collectively, the tiny particles that make up "finished compost" is always very water-retentive in a container, and compacts readily. If the compost is still chunky, it's 'unfinished', meaning the composting process is still ongoing. Unfinished compost tends to immobilize nitrogen, making it difficult to supply enough N w/o over-supplying other essential nutrients.

You can make a very productive and easy-to-grow-in medium by mixing 70-80% pine bark (size dust to about 3/8") with 10-15% each of perlite and either compost, sphagnum peat moss, or commercial potting soil, with an appropriate measure of dolomitic lime added to adjust pH.

Al

'Potting soil' you buy in bags for pots IS in essence compost (usually from leftover bark). So yes, you can plant in pure compost. Don't let it dry out too much though or it becomes hydrophobic.

Of course one "can" pot plants in pure compost, but don't expect results equal to what you might expect when using a well-structured grow medium.

Finished compost is VERY water-retentive and invites root health/function issues. Unfinished compost invites the same root health/function issues along with nitrogen immobilization, and ammonium toxicity caused by soil compaction and/or the lack of oxygen that comes with excess water retention.

Al