I have forsythia and other bushes that the branches seem to grow horizontally. The forsythia is lanky, not very full at the bottom, almost as though they have a stem or trunk like a lollipop. I have read to resolve this configuration lopping to 2-4 inches off ground and essentially starting over to encourage “basal” growth. Can you explain what the term basal means and why the branches seem to grow out across horizontally?
Basel growth is a term I see most often used in pruning Roses.
Here are some excellent articles about pruning your Forsythia the correct way.