Overview
- Garden advisors say hydrangeas should be watered deeply and consistently through late autumn until the soil freezes to prevent bud loss and poor spring flowering.
- Once the ground is frozen, roots cannot take up moisture, so plants that enter dormancy already dry are more vulnerable to winter damage.
- Check soil weekly by touch or moisture meter and water in the morning so moisture can soak in before evening temperatures drop.
- A slow trickle method—such as a bucket with a small hole placed at the base—helps deliver water to deeper roots for better cold resilience.
- Mulch to protect roots while leaving about a two‑inch gap around the stem, remove damaged or diseased branches, and time pruning by type, with new‑wood pruned in winter dormancy and old‑wood after blooming; potted plants benefit from occasional daytime watering above freezing.