Hi. My hyssop is about 3 or 4 yrs old. Until last year I had alot of leaves and alot of flowers on it. (I'm in zone 6). It is now the last week in May, and I have about two small clusters of leaves at the bottom of the plant, and no flowers in sight. what could have happened, and what can I do? thanks
Do you have winter temps colder than normal, or even a wet spring weather could have caused some root rot.
As long as you are seeing some new growth, your plant should make a comeback.
Hyssop does not really need any fertilizer, you could add some compost around the plant this spring for a boost.
Give it a bit more time.