Question
I want to do a science fair project on organic fertilizers(cow manure) versus compost versus ? does it effect size of plant better growth or maybe the project is does it increase speed of seed germination what do you think is a good question or topic can you give me any tips also should I use a grow lamp in pa in sept/oct

Answer
Great Science Fair topic, Catherine.

First, if you are going to use Manure to grow anything, it must be AGED (also called "CURED") Manure.  Fresh Manure (usually less than 1 year old) will burn the bejeezus out of anything you try to grow.  Aged Manure is safe and healthier for the plant.

Now, if you were my daughter, I would recommend you get yourself some nice radish seeds to plant.  Radish seeds germinate quickly.  Your teacher might have other ideas for quick sprouting seeds.  I like Radishes because after you see them sprout, and grow, you have Radishes at the end that are easy to weigh and examine.

Get yourself some sand and grow, say, 5 pots of radishes next to one another, with perhaps 2 or 3 seeds per pot.

One pot has 50/50 sand/Manure.

One pot has 100 percent sand.  You fertilize it with Miracle Gro as directed.

One pot has 50/50 sand/soil from outside.  You fertilize it same as above with Miracle Gro.

One pot has 50/50 sand/Compost.

One pot has 100 percent sand.  No fertilizer.

Take pictures (digital) every day of your windowsill Radishes.

In 45 days, harvest them and weigh each Radish.  I think you'll be very surprised at the results.

Don't forget to come up w/ a hypothesis about which pot will grow the biggest Radishes.  This will be fun.

Any questions, ask.  I'd love to hear how it all turns out, even if you decide on another experiment.

Thanks for writing!

THE LONG ISLAND GARDENER