While experimenting with fertilizers, students at a UK boy’s business school found that sprouting pumpkin seeds in coffee grounds instead of their usual manure yielded great results. Besides the pumpkin, a crop of grapes sprouted in the coffee is also doing well. The seeds sown in horse manure did not do that well. Neither the school staff nor the students had an explanation for the success of the coffee grounds as seed germinator, but a commenter to the article stated that it’s the nitrogen in the grounds which do the trick.
Coffee grounds have been used for years in composts, which mix a lot of garden waste, grass clippings with water and cow manure if obtainable. The pumpkin seeds not only sprouted well, but the plant thrived so well, it’s now a 16 foot long vine. The article didn’t say anything about the actual fruit, and the picture shows a flower but no pumpkin. It may be the planting was done too late in the year for the pumpkins to be ready for a Halloween harvest. It also might be that the flowers did not get pollinated. Sometimes when bees aren’t around, the pollination has to be done manually. But the vine sure is impressive.
If you want to try sprouting pumpkins in coffee grounds, make sure you start early enough in the year to give the pumpkins lots of time to grow. Also, if pollination doesn’t occur naturally by the bees, you’ll need to take a brush and remove pollen from the male flower and brush it into the female flower. Keep composting with coffee ground compost and some great pumpkin fruits should be available to harvest by Halloween.