Weed Block Fabric Under Raised Bed good or bad

[Babbette]

Hello I am in zone 9 and got an early jump on a raised garden plot 4 x 8 ft using the square foot garden approach (1/3 vermiculite, 1/3 compost, 1/3 peat moss). I used the landscape weed block directly over my lawn. Now I have mushrooms in the shallow end ( 6 inches deep) and am concerned the tomato end ( 12 inches deep) will not allow roots to grow deeply due to the weed block fabric. Good idea to use it or should I have removed the grass and placed the raised bed on bare earth? Is my only option to jerk the fabric out or should I puncture through and forget the weed block barrier?

[tomc]

Year by year it will (the garden fabric) be bypassed as roots grow through it. You will also dig it up as you turn the bed. In time and in pieces it will be removed.

I'd use a doubled up layer of cardboard on subsequent beds, as a light and weed barrier.