Mushroom spawn is classified under 060290 alongside other live plants, but its regulatory treatment differs: APHIS evaluates spawn for plant pest risk, and importers may need to demonstrate that the spawn is free of regulated pathogens. Requirements vary by species and origin, so checking with APHIS before the first shipment is advisable.

Unrooted cuttings and slips — propagation material that has not yet developed roots — fall under 060210. Once the cutting has been rooted, whether in soil, rockwool, or another medium, it becomes a live plant classified under the appropriate species-specific subheading (060220–060240) or the residual 060290.