Why weeds grow in paver joints, and how to stop them

The common assumption is that weeds push up through the base. They do not. Seed lands on top and germinates in whatever is sitting in the joint.

What is actually happening

Wind and birds deposit seed. Dust, organic matter and degraded joint sand collect in the gaps. That mix is a perfectly good seedbed, and it is entirely above the pavers.

The fix

Clean the joints out properly and refill with polymeric sand to depth. A set joint gives seed nowhere to root.

Maintenance

Sweep regularly so organic matter never accumulates, and top up joints every few years. On a plowed driveway that interval is shorter.

What not to do

Do not blast the joints with a pressure washer every spring. It removes what is holding the field together and guarantees the problem returns worse.

Interlock maintenance