If you overwatered
Bigleaf hydrangea, you might want to take a few steps back and prevent further damage.
Bigleaf hydrangea is hardy, so they have a higher chance of surviving. Give the plant a chance to dry everything out and stop watering it. The plants don’t tolerate their roots sitting in water for longer, so aerating can help.
Some of the symptoms of an overwatered plant will be premature falling of yellow leaves. You might also see fewer flowers and misshapen buds. In more serious cases, this can result in wilted and brown leaves. Long-term overwatering can result in root rot.
The symptoms of underwatering can be similar. Wilting
Bigleaf hydrangea can be a sign of underwatering. Feel the earth by sticking your finger into the soil, and if it’s too dry, then this is a sign of dehydration. Too little watering can also happen, so you might want to add some in the evening. Always check the soil for dryness and follow the regular schedule of watering in the morning.