Homemade
Weed Killer

To make this homemade weed killer, mix:

• 1 quart vinegar (I used white vinegar but I've heard that apple cider vinegar works -- it has a slightly higher acidity level, so it probably will work even better)
• 1/4 cup salt
• 2 tsp. dish soap (I used the Dawn soap I use for my homemade laundry detergent, but any kind will work)

The vinegar's acetic acid is what kills the plant. The salt assists by pulling the moisture out of the weeds.  The dish soap helps the weed killer stay on the plant once you spray it. Word to the wise: this weed killer will kill any plant it comes into contact with; it's not selective at all. 

Can I seed in the Spring?

Yes, apply seed in Spring when soil temperature reaches 15°C (60°F) - Ideally mid May to mid June. If you have spread grass seed in the early spring, it will not germinate until the soil temperature reaches about 15°C (about 59°F). 
(Reference: fairgreensod.com)