Why should you put tulip bulbs in a freezer before planting them?

You shouldn't. If you live in a climate that doesn't have long, cold winters, you need to treat tulip bulbs in a way that mimics those conditions before you plant them in the ground. the conditions underground are wetter and warmer than your freezer.What you need to do is put the bulbs in a flowerpot with a little gravel on the bottom and filled with a light potting mix that drains well. Water the pot with its bulbs and soil in it thoroughly. Put a plastic bag with a few holes poked into it over the pot and put it in your refrigerator for 12-15 weeks. You can also put it in a basement or anyplace that has a steady temperature of around 45 degrees. When you see the shoots beginning to poke up out of the soil, put the pot in a north-facing window or somewhere out of direct light, and water the plants lightly. When the shoots are six inches high or so, put the pot in direct light, and water them when the top half inch of soil dries out. After the flowers have faded and fallen off, cut the flower stem off, and leave the leaves on the plant. Now you can fertilize it with a pellitized, organic fertilizer. Put the plants back into indirect light and reduce watering. When the leaves shrivel up and turn brown, leave the pots in a cool, dry place for a while, then start the whole process over again.