Why You Should Keep Watering Your Garden in Fall: Pros Weigh In on Winter Prep
Why fall watering matters
As the growing season winds down, plants may still be developing below ground. Natalie Carmolli, a shrub expert with Proven Winners ColorChoice Shrubs, says roots can continue growing until soil temperatures fall to about 40°F.
New plants and seedlings have shallow roots and need moist soil to survive, says Stephanie Rose, author of The Wild & Free Garden and founder of Garden Therapy. Mature plants can draw on water deeper in the soil, so they generally need less support.
How much water to provide
A useful target is about an inch of water each week, including rain. Carmolli says watering is due if there has been no soaking rain for a week to 10 days.
Fall watering should be less frequent than in summer. Cooler weather and shorter days mean less water leaves the soil, Rose says, and gardeners should avoid saturating the ground.
When to stop watering
Keep watering after leaves have fallen and frost has arrived. Carmolli advises continuing until the ground freezes, which may happen in late November or December depending on the location and the year.
The timing varies, so gardeners should consider local conditions rather than stopping after the first frost. Moist soil can support roots as they continue growing before the ground freezes.
Chores to avoid now
Fall is not the time to fertilize, because encouraging tender new growth before winter can be harmful. Carmolli also advises against pruning shrubs late in the season unless a branch is broken.
Some shrubs, including many hydrangeas, are already forming next year’s flower buds, Carmolli says. Late pruning may stimulate new growth and remove those buds.
Key points
- Roots can keep growing until soil temperatures reach about 40°F.
- Aim for roughly an inch of water weekly, including rainfall.
- Water less often than in summer and avoid waterlogged soil.
- Continue watering until the ground freezes; timing varies by location and year.