Baking or microwaving birdseed will change it's nutritional value - which kind of defeats the purpose of feeding the birds in the first place. Also, several informal tests have been done and it doesn't seem to affect the germination rate that much anyway.

A better thing to do is to look at how you're feeding the birds. Are you feeding a seed mix that has a large number of discarded or uneaten seed? Buy a better mix that doesn't contain the unwanted seeds or make up your own. You'll have less flinging about of seeds as they try to get to what they want this way too.

If the birds like all the seeds in your mix, but there are still lots germinating, then feed less. Make the birds have to hunt down the last few seeds rather then eat at the all you can eat buffet that is refilled as soon as it gets low.

Maybe you need a different type of feeder. One that allows easier access to the seeds. The ideal sort will depend on the sorts of birds you have or want to attract.

And lastly, if the scattered seeds are in a bad place to hunt down, move the feeder to a better place.

BP

I solved my sprouting bird seed problem by switching to sunflower chips -- sunflower seeds without husks and cut up so they won't germinate. Although more expensive per bag, a bag lasts a long time as all the weight is seed.

I've recently noticed a lot of weeds germinating under shrubs and bushes that are frequented by the same birds that feed at my feeder. After doing a test germination of the seed I put in the feeder, I found the weed species I have found all over my yard is in fact the same as germinated from the test. It appears the birds are passing these seeds in their droppings when roosting in the bushes. Maybe I'll try the sunflower chips and avoid other seed species altogether.

I have the same problem too. I have bought seed aimed at specific bird species (cardinals, goldfinch) hoping to avoid other types of birds who scatter seeds all over the place, but the other birds come just the same.

I have witnessed birds perched on the feeder, purposely scattering seeds and then flying to the ground (where they feel more secure) to feed on them (larks, sparrows, etc.). It's in their nature.

So I will be sterillizing the rest of my seeds since the site linked below says there is no change in the nutritional value in the seed.

BTW, here are a few tricks I use to keep squirrels from my feeders:

I have one feeder attached to a type of bungey cord hanging from the branch of a huge spruce. When I first hung it, it was too close to the trunk of the tree so the squirrels could jump from the trunk to the feeder. I then moved it further away from the trunk and that did the trick.

I have two more feeders hanging on a double sheppard hook. Last year I spread tanglefoot along the trunk of the hook so the squirrels could no longer climb up to the feeders. I did the same to the hook with my hummingbird feeders to keep the ants away. The tanglefoot lasts all summer but has to be reapplied the following year.

Here is a link that might be useful: Sterilizing bird seed, and other info