Question
I am building raised beds for my garden and need to kill ALL weeds %26 grass before doing so. it is now winter will tilling the ground several times freeze out the weeds? I am raising the beds with railroad ties about 9" high and will be filling with compost, sand, Vermiculite and peat moss, will that help to kill the weeds?  HELP?

Answer
Dear Tony:

I have raised bed gardens.  In preparing the beds, I dug out the existing top soil to a depth of approximately 4 inches and used it as fill uneven depressions in my lawn. After placing the timbers in place for the sides, I filled the bed with a mixture of sand, vermiculite, and bagged top soil.  I recommend this method, however you can kill the weeds by applying an organic weed killer spray mixture:

Organic Weed Killer

Ingredients

1 liter (35 fl. oz) of boiling water (hot tap water will also work but not quite as well)
5 tsp. vinegar
6 tsp. salt (regular table salt)
1 Tbsp. lemon juice
2 tsp. dishwasher (machine) detergent (powder is better than liquid, but liquid will work)
Directions

Mix all together. Take care with hot water!

Natural Weed Killers are simple substances with a direct and obvious action. They destroy plant life for a short period. They are substances encountered naturally but in small quantities. Their presence is well-known and normally not harmful. But when applied in larger doses the results are usually obvious in a very short time. As always, these methods need due caution so please wear protective eye/hand/body protection.

This weed killer acts at the point they are used. After treatment their damaging effect is dissipated. Vinegar is made of Acetic Acid along with other weak organic acids. It has become a popular 'cottage garden' alternative for those who dislike modern herbicides. This mixture works by disrupting membranes and causing leakage of plant cells. The damage to plants appears rapidly and even quicker on hot days. The acid is not around long enough to have any lasting effect on earthworms, soil invertebrates or organic matter breakdown. The good news is that it won抰 cause any lasting or apparent harm to pets or children.

Best wishes and happy gardening!

Regards,

Mack Jean
AllExperts
Master Gardener
Tennessee