Question
I have a completely raised bed that had a lot of mushroom compost added 3 years ago. I plant tomatoes.  They did well for those years.  However, The soil has become "heavy" and dark and I do not know what type of amendments to add for improved drainage.

Answer
Hi Renee,  I'd add finely ground pine bark.  Usually it is sold as a "soil conditioner".  I'd add about 2" to the top and till or turn it under evenly into the top 6-8" of soil. If you can't find ground bark, then cotton burr compost, leaf mold or any fairly coarse soil amendment will work.  Jim