36 Pack Refill Sponges for the 18-cell Planting Block

I have been starting seeds inside for 50 years. For the past three I have been using the cell blocks, sometimes with the cover on and sometimes with the cover off. I have been using all three sizes of the cell blocks. These are excellent, no mess, easy clean up. I bleach the styrofoam cells containers and use them over and over. I highly recommend them!!

For 6+ years I have used these for successfully starting my bush French Beans indoors to speed up the season and harvest. I can control the temps and germination more easily and plant 5 inch bean plants outdoors instead of seeds! All of my bean transplants have always survived the process. I did have to replace the foam blocks after 5 years. They would have probably made it another year or two, but they were getting a little broken up from heavy Spring use. I have already brought them out and gotten them ready to go for beans!

Have used bio dome sponge inserts for tomato and pepper seed germination for several years with perfect success. Place bio dome in window of our sunroom in January; daytime sponge temps with the dome vents closed are in the 80's to 90's. When seedlings are an inch or so high, open vents. When seedlings reach the dome, I transplant to 4" pots. Great system. Plants go in the ground in March (San Diego, CA).

I have purchased and used the 18 count bio-cells for quite a few years now. They are perfect for starting tomatoes and like plants which grow inside to a pretty good and strong size - ready to transplant direct to the garden.

The Biodome works really well. I use it with the 18-cell block for any seeds that grow big fast, or which I may want to delay transplanting (for example waiting for the weather to warm up). The description of the product above is accurate except for one thing -- the polystyrene block is actually rather fragile, because the edges are too thin. Since the 18-cell block is smaller than the Jumbo and Original blocks, it could be made MUCH more sturdy and still fit well into the Biodome. Its too bad the manufacturer/designer was so greedy early on, since redesigning and retooling would cost MUCH more than the insignificant difference in cost of more styrofoam. I think Park's should pressure them to do it anyway -- it is the difference between shoddy and excellent. I would have given it five stars except for this