As with most of my “brilliant ideas,” this one was copied from someone else. I first thought of using K-cup pods to start seeds when I read a Craigslist ad requesting used K-cups. The ad said to keep the cup intact and just allow the coffee grounds to dry out; he would use the whole thing to start seeds. I noticed that the cup seemed to have about the same volume as a cell in a six-pack, and had a drainage hole already punched in the bottom, so why not try it?
LAST YEAR’S TRIAL
I sowed one tomato seed in each of two cups last year, preferring to replace the coffee grounds with potting mix. It worked well, and I potted up the little seedlings when they had their first set of true leaves. The only drawback was that the potting mix was a little too moist when the root ball was removed from the K-cup for transplanting. I plan to compensate this year by punching an extra drainage hole in the bottom.
PREPARING THE CUP
Recently when I removed a used cup from the machine, I turned it around 180 degrees, inserted it again and lowered the handle to punch a second hole. (You could probably add more holes this way if you wanted to.) Then I set it aside until I had a small collection of them.
The typical K-cup pod has the coffee grounds contained in a tiny filter, which is suspended just above the cup bottom, creating an air space between the bottom of the filter and the bottom of the cup.
Other gardeners make use of this filter to keep the growing medium suspended also, but I found it easier to just insert my thumb and rip out both the grounds and the filter, leaving only the cup with the holes in the bottom. (Save the grounds for a soil additive to use in your garden later.) Wash out the cup or clean it in the dishwasher.
SOWING THE SEEDS
Fill the cup with moist potting mix and plant the seeds according to package directions. Write the variety name on the cup with a Sharpie pen. Put the cups in a flat-bottomed container and cover with plastic wrap. It helps germination to place the cups in a warm spot, but don’t let the mix dry out.
As always (you know the drill) as soon as you see the seedlings break through the soil, remove the cover and put the cups under a bright light…or outside if it is warm enough. Continue to keep the soil moist and wait for the true leaves to appear.
When the first true leaves have appeared on your little seedling, it’s time to transplant it to a larger container. Fill the larger pot with moist soil mix and make a hole just about the diameter of the root ball. (Remember that tomato seedlings can be buried deeper because the buried stem will form additional roots.)
Place your index and middle fingers in a V-shape on the soil surface—one finger on each side of the stem. Turn the K-cup over.
To remove the plant, tap UP on the K-cup rim, not DOWN onto its bottom. (I learned this method from my garden-loving father, and it seems to work well no matter what type of seedling container you are using—from cell packs to larger pots.) Lift off the K-cup and your V-shaped fingers will hold the root ball.
Carefully turn the seedling right side up and place it into the hole you created. Firm the potting mix around the seedling, which will be happy in its new home!
NOW YOU TRY IT
How many cups of coffee will you be drinking between now and next spring? Even if you don’t have a Keurig machine, you probably know someone who does. A local restaurant or business may be happy to give you their used pods. My bank has a Keurig machine in the lobby for courtesy use by its account holders. Theoretically you could even wash and reuse the same K-cups repeatedly to start seeds. You may never have to buy cell packs again!