Severe!!!! pruning very tall Forsythia
When I bought this property in 2000, the fairly long winding driveway had a row of tall Forsythia in partial shade in Tolland County's rocky soil. The plants were tall, some as high as nine feet. Most of them had no branches until about three feet up. Diagnosis: no pruning for many years, plus perhaps seeking the sun.
I pruned out the vine-like branches and took a little off the top. I fertilized twice. Two years later, the plants had a more prolific bloom, but they were just taller. Repeating this from year to year, I have a collection of plants than bloom like yucca or candlesticks: everything is at the top.
I know that even the most severe pruning should leave a strong bud on a branch. However, that would only shorten plants that would still have no blooms until about three feet up.
One poster on the poll on pruning Forsythia says that he tried to kill his plants by severe pruning, which I would take to mean cutting them with no buds remaining. The plants did not die, so he had to pull them up.
If Forsythia is that robust, would I be able to prune the plants back down to bare branches and expect the plant to be able to generate branches and leaves from stored resources? I am considering removing the plants and starting over, so I would be willing to risk killing the plants. A compromise would be to prune every branch down to a strong bud, and trust the weeping habit of the plant to provide flowers nearer the base. I know that I'll have zero blooms next year.