Help with ripped knees?

Help with ripped knees?

My son grows like a weed to begin with so we go through pants every 3 months on average. Of course these days he has been killing the knees in them WAY before he outgrows them. Any suggestions on how to prevent or repair this? Standard sewing store patches just look awful and are expensive to boot, and I can NOT afford to spend $200 a month on pants for this kid which is what it would cost me to replace them at the rate he goes through them cause he requires Slim size jeans (holy run on sentence Batman!) Mind you I am saving the ones with holes to make shorts out of for warmer weather, but he still needs clothes for the winter. Edited to add: He is only four years old, so there is only so much I can avoid. Thanks everyone for the wonderful suggestions and keep em coming, I will be trying many of them out over the next few weeks.
My landlords didn’t work out

My landlords didn’t work out

Gross Bugs.

Gross Bugs.

Refresh my memory please – tomatoes

Refresh my memory please – tomatoes

Some flowers growing in our backyard

Some flowers growing in our backyard

The Mesclun Jungle

The Mesclun Jungle

Waiting

Waiting