Starting Plants From Seeds Update!

March 18, 2013

Hard to believe, but Saturday it was 3 weeks since first planting tomato seeds and more in the Biodome from Park Seed.  Not every seed sprouted, but most did, and grew quickly. This is the fun part of starting seedlings indoors!

pic of planting tomato seeds

As you can see, many of the seedlings were already touching the top of the bio dome, which is 4-inches from the edge of the planting tray to the top on the side.  In the middle, the dome is about 4 3/4-inches tall.

With starting plants from seeds, I never expected them to grow quite so big in just 3 weeks.

pic of tomato and pepper seedlings

At any rate, with the seedlings brushing the top, and a couple were even bent over, it was past time I got them out of there and into bigger pots!

I discovered just how badly they needed more space when I pulled the little sponge plugs out of the tray, and out came some long, long roots!  Here’s an example with 3 of the Super Sauce Tomato seedlings:

pic of seedling roots
One of the things Park Seed said in their description of the seed starter kit Biodome was:

And our growing medium — the Bio Sponge — encourages root growth downward, NOT in an upward spiral…  Before and after germination, your seeds receive just as much light, water, heat, and air circulation as they need, thanks to the adjustable vents and bottom-tray watering design of the Bio Dome.”

That certainly seems to be true of the water part at least, because I kept a fair amount of water in the bottom tray, and the little sponges almost seem to have acted as a medium in hydroponics.  The roots of the seedlings grew down into the water.  It seems to be a really good way of starting seedlings indoors.

Starting Plants From Seeds in Sponges or Soil Mix:
Which Is Better?

Also, it was actually kind of a good thing they didn’t send quite enough of the Bio Sponges to fill the tray, because filling the one empty hole with the regular growing medium allowed me to see the difference between how well the two different systems work – sponge vs. regular seed starting mix.

pic of greenish poitting soil

The picture didn’t come out real well, but here’s the scoop: the regular seeding starting mix stayed too wet. The soil is scummy with green algae on top, and the seed did not sprout.

I didn’t transplant all the seedlings, just the biggest ones.  Mostly I was planting tomato seeds in the planting tray, so I ended up with 17 little pots with a tomato plant in each.

Potted Seedlngs

Hopefully they will continue to grow well so they’ll be nice, sturdy plants when it comes time to put them in the garden!

Burpee Gardening

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