ForcedCreator
You’ll want to deadhead it by removing any dying blooms about a 1/4” to 1/2” down from the top of each stem. You will also want to cut back any stems which only have dead, crispy leaves. Leave the partially alive leaves as the plant can either make use of what remains or draw back the nutrients left in them if it needs to.
Try to water it every morning while it is still cool. Error on the side of giving it too much water at once over watering it multiple times per day. Stick your finger in the dirt before you go to water it. Pull your finger out and check if the soil feels moist or muddy. If it does, you will want to skip watering that day.
Mistakes happen when it comes to watering. If it happens again, fill up some Tupperware or a large bowl with water and place the pot the marigolds are in into the water for a little bit. This will quickly rehydrate the soil and the plant (assuming there are holes on the bottom of the pot).
After you’ve trimmed it back and taken care of its water needs, watch to see if it bounces back. Being honest, there is a small chance it could completely die at this point.
Look for new stems and buds at this point. If it looks like it’s bouncing back, give it liquid plant food or fertilizer. You will want fertilizer/ food which is high in phosphorus. Avoid high nitrogen fertilizers, otherwise it may make more leaves than blooms.
Also, consider repotting it into a 12” pot if it bounces back.