I do that too. I have quite a bit of them stored on a shelf in my garage. As a matter of fact, my whole garage looks like a storage center. I have buckets filled with decorative garden stakes. Watering cans stashed in corners. Flower pots nested together, and plastic bins filled with fairy garden stuff. That's MY side of the garage. Hubby has his tools, leaf blower, mower, and other stuff on the other side. It's a wonder the car fits in there.

Great idea! With 6-packs and 4-packs, each pack can be sown with just one kind of seed. You don't need to have a whole tray with 74 cells and 6 different kinds of seeds, all emerging at different times.

I do that as well Rita.

Always good to reuse.
Since I don't buy anything that comes in those packs I usually hunt for the ones discarded by landscapers and homeowners on recycle day. I just wash them and give them a rinse in a mild bleach solution. Love saving money.

I also reuse them, but I sanitize them in a 10% bleach solution to avoid spreading any disease,

Sometimes I use my dishwasher to thoroughly clean inserts and sections of -lug trays that I re-use. I always get the soil and visible stains off first, by spraying, soaking and scrubbing.

Then I fill the dishwasher as full as I can with 6-pack inserts, plastic pots and sections of trays. I add detergent manually so that every part of the cycle becomes a "wash" cycle. I seem to have a pre-rinse, then a pre-wash, then the main wash, then a rinse cycle. Instead I turn those into 4 wash cycles, and do the rinsing outdoors with a hose set to "mist" or "flat spray".

Each batch of trays and inserts gets 5-7 minutes of washing, then I remove that batch and put the next batch in. I can get 5-6 batches through one dishwasher cycle.

The bleach rinse might get them more nearly sterile, but the dishwasher does get them very clean.

P.S. Modern "laundry bleach" is an oxygen-based "bleach" and very weak tea compared to traditional BLEACH (sodium hypochlorite). If you want to sanitize or sterilize something, you want traditional Chlorine-based bleach. If a jug says "laundry bleach", read the fine print and look for "sodium hypochlorite" (effective for sterilizing things) and anything else, usually starting "oxy-", which does not kill microbes.