There really wasn't space for a large plant with lots of leaves and an extensive root system.  The plant would probably stay alive if the stem was in water, but you have to be careful the butterflies can't fall into the water.  We found an old, plastic film canister that was big enough for a borage stem and some water, but not so big that the butterflies could fall into it.  Of course, the plant is huge compared to the film canister, so it would just topple over as soon as I put in down.  

We put the film canister into a larger, plastic cup.  That give it a bit more stability, and seemed like it would work.  We put it into our butterfly habitat.  

The butterflies noticed it immediately.  They completely ignored the little garden, but they are climbing all over the borage leaves.  In fact, we saw the first egg about 5 minutes after the plant was put in.  They must have just been waiting for something to lay their eggs on.

Here are some pictures of a butterfly laying an egg.

First, look at the picture on the left.  The butterfly's abdomen is almost touching the leaf, but there's nothing on the leaf.

Next look at the photo on the right.  You can see the tiny white dot that is underneath the butterfly at the same spot where the abdomen touched the leaf.  I've read that the eggs are the size of a head of pin,  these eggs are smaller than the head of a pin.

Here's a close-up on a leaf with some eggs.

That section of the leaf is about 2 inches (or 5 cm) wide.  

The butterflies have been very busy laying eggs everywhere.  My son has been counting and he can see over 50 eggs.  There are a lot more than that!

Anyone want some caterpillars?

Here are some pictures of the eggs taken with our digital microscope.

10X

200x

The eggs are a beautiful, pearl color.  I was amazed to see the interesting shape of the eggs. 

Read more about raising Painted Lady Butterflies.