Q.What fertilizer to use on Lily of the valley
What fertilizer should I use to enhance blooms on my Lily of the valley? Please recommend a brand name.
Generally Lily of the Valley do not need a lot of care, but if your soil conditions and your plants need a little boost you can use an all purpose-slow release fertilizer.
Spread over the soil and around the lily pips after they have finished blooming this spring or summer. Rake it into the soil and water lightly.
Do not apply directly onto the plants. You can reapply in the fall mixed into compost. This will help condition your soil.
https://www.gardeningknowhow.com/ornamental/bulbs/lily-of-the-valley/growing-lily-of-the-valley.htm