I have been using these Jiffy-Strips for several years. One pack fits perfectly in a tray easily. The plants will grow to a good height for planting in small gardens. They hold moisture even on hot dry days.
This product is excellent for the jiffy indoor greenhouse starter. The only problem is the local store has been out of stock and this is peak season for gardening. My garden consists of tomato, peppers, eggplant, okra, sugar peas, bush beans and sunflowers, all that started indoor with these starter pots
I currently have about 7 of these strips which is a total of 70 pots with seeds just starting to sprout. I'm starting 12 different herbs in these guys. I absolutely love them. Unfortunately I had found out about these after i had started the majority of my current garden(sunflowers, tomatoes, cucumbers, peppers, squash, tomatillos, pole and bush beans, and more). Next year I'll be sure to use these for the rest of my garden as well.
I use these pots to start my plants indoor but after a while these pots get MOLDY. My pots get white fuzz on the sides then it becomes full blown mold taking over. I don't over water the plants i just water enough so that the soil is moist, once a day. The pots seem to wick out the moisture from the soil and provide moisture for the mold. I don't know how you could avoid doing this besides letting the soil dry out which also means you'll be harming the plants. Youre best off getting plastic cells and reusing it over the years which actually can save you money.
The Jiffy Strips work well for a first transplant of tomato and pepper plants and for seeding large seeds such as asparagus and artichokes. They are OMRI approved. They can get mold; use your fingers to press on the mold which seems to control it. avoid over watering, put flats in the sun for a day or two if possible.