Minnesota & Seasons
Fall watering: when can you stop?
Keep watering trees, shrubs, evergreens and anything planted this year any week without about an inch of rain, right up until the ground freezes. Around East Bethel that’s usually around Thanksgiving. Water slow and deep at the roots, then drain and disconnect your hoses so the outdoor faucet doesn’t freeze.
Fall is when a lot of people stop watering, and it's one of the most common reasons plants die over the winter. The leaves may be off, but roots keep growing until the soil gets close to freezing, and evergreens lose water through their needles all winter long. A dry fall followed by a cold, windy winter is the combination that kills shrubs.
What to water first
- Anything planted this year: trees, shrubs and perennials. Their roots haven't spread into the surrounding soil yet. See protecting new shrubs.
- Evergreens, especially arborvitae, yews and boxwood. Dry roots going into winter are the main cause of the browning you see in March (see winter burn).
- Young trees in their first few years.
- Perennials planted this fall, which need moisture to root in before the ground freezes.
Established lawns and perennials that have been in the ground a few years can usually get by on fall rain, unless the fall is unusually dry.
How much and how
- Go slow and deep. A hose at a trickle at the base of a shrub for 20–30 minutes, or a soaker hose run for an hour or two, soaks the root zone without running off. A quick spray from the nozzle wets the surface and not much else.
- Aim for the root zone, roughly the area under the branches, and a little beyond on trees.
- Check before you water. Push a long screwdriver into the soil. If it slides in easily 6–8″, the soil is moist; if it stops short, water.
- Water during the day when it's above freezing, so the water soaks in before night.
When to stop
Stop when the ground freezes and water won't soak in anymore. Then disconnect the hoses from the house, drain them, and store them, or the outdoor faucet can freeze and crack inside the wall. If your faucet isn't frost-free, shut off the inside valve and open the outside tap to drain it.
If we get a long warm, dry spell in winter with the ground thawed, usually in March, it's worth giving young evergreens one more drink.
Containers and new plantings
Pots dry out fastest of all. Anything you're overwintering in a container (see winterizing pots) still needs water now and then. Perennials and bulbs planted this fall need a good soak right after planting and every dry week after that until freeze-up.
Common questions
When should I stop watering in the fall in Minnesota?
Keep watering trees, shrubs, evergreens and new perennials any week without about an inch of rain, right up until the ground freezes. Around the Twin Cities that's usually around Thanksgiving. Then drain and disconnect your hoses so the outdoor faucet doesn't freeze and crack.
Do I need to water evergreens in the fall?
Yes, and they need it more than anything else in the yard. Evergreens keep losing water through their needles all winter, and a plant that goes into winter with dry roots is the one that turns brown in March. Give them a deep, slow soak every dry week until freeze-up.
How long should I water a shrub in the fall?
Run a hose at a trickle at the base of the shrub for 20–30 minutes, or a soaker hose for an hour or two, so the water soaks into the root zone instead of running off. To check, push a long screwdriver into the soil: if it slides in 6–8 inches, the soil is moist.
Should I water in the winter?
Only if the ground thaws during a long, warm, dry spell, which usually happens in March. Then give young evergreens one more deep drink.