Q.I Have Nepata Nuda In A Nursery Bed To Grow On From Small Pots Purchased Early Summer. All Were Doing Well, But Leggy. Over Ghe La
st week 3 had all leaves and stems ture gray brown a brittle dry. The others are pushing out new growth at the ground. Ant thought s – I am suspecting a watering issue, but I don’t know if it is too much or too little.

Certified GKH Gardening Expert
It could be either! Unfortunately, your photos did not come through, so I cannot assess the damage.
Usually, they will suffer from overwatering, more than under. Make sure to let them dry out some between waterings.
You may need a fungicide. This article will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
Here is an article to help you with catmints:
https://www.gardeningknowhow.com/edible/herbs/catmint/catmint-plant.htm