Fall Watering in Northern Nevada: When & How Much

Fall in Northern Nevada can be deceptive. The mornings are crisp, evenings are chilly, the days are getting shorter, and you may even wake up to frost—but that doesn’t necessarily mean your landscape can go without water.

In fact, proper fall watering can make a big difference in how well trees, shrubs, perennials, and other landscape plants make it through winter and return in spring.

So when should you cut back? How much water do plants actually need as temperatures cool? And when is it finally safe to turn off the irrigation? Here’s a simple recommendation for navigating fall watering in our high-desert climate.

Don’t Stop Watering Just Because It’s Cool

One of the biggest fall watering mistakes is shutting irrigation down as soon as daytime temperatures drop.

Plants generally use less water in fall because cooler temperatures and shorter days reduce evaporation and slow growth. But roots remain active even after the greenery of the plant has slowed down or gone dormant.

That’s especially important for anything planted recently. New trees, shrubs and perennials need adequate moisture around their roots as they head into their first Northern Nevada winter.

Instead of stopping abruptly, begin reducing the frequency of watering as temperatures cool.

Water Less Often—but Water Deeply

Fall is a safe time to move away from frequent, shallow watering.

For established trees and shrubs, a slower, deeper watering encourages moisture to reach farther into the root zone. Allow the soil to begin drying between waterings rather than keeping the surface constantly wet.

Remember that different parts of your landscape have different needs. A mature tree, a newly planted perennial and an established lawn shouldn't necessarily be watered on the same schedule.

And don't rely on the surface of the soil alone. It can look dry on top while still holding moisture several inches down.

Before watering, check the soil. Dig down a few inches near the root zone. If it's still moist, wait. If it's becoming dry, it's probably time to water.

Pay Extra Attention to New Fall Plantings

If you took advantage of fall's cooler weather to add trees, shrubs or perennials to your landscape, those plants need a extra tender loving care. Their roots haven't had time to spread into the surrounding soil, so they're more dependent on moisture within the planted root ball.

Check new plantings regularly and water deeply enough to moisten the root ball and surrounding soil. You want consistent moisture while the plant establishes—not constantly soggy soil.

This is also why fall can be such a great planting season in Northern Nevada. Cooler air puts less stress on new plants while the soil can remain warm enough for roots to continue establishing.

What About Frost?

A frosty morning doesn't automatically mean it's time to stop watering for the year.

Northern Nevada often experiences cold nights followed by sunny, relatively mild days. Rather than using the first frost as your signal to shut everything down, pay attention to soil conditions and the weather forecast.

When watering during cold weather, aim for the warmer part of the day so water has time to soak into the soil before temperatures drop significantly overnight.

Avoid watering when the ground is frozen or when water is likely to freeze on hard surfaces.

When Should You Turn Off Your Irrigation System?

There isn't one perfect calendar date for Northern Nevada. Our fall weather is fickle from year to year or even month to month, so it's better to watch the forecast than simply shut irrigation off because October—or even November—has arrived.

As freezing nights become more consistent, it's time to protect and winterize irrigation systems.

But winterizing your irrigation system doesn't necessarily mean your plants will never need water again.

If we have an extended stretch of dry weather without meaningful rain or snow and the ground isn't frozen, trees and shrubs—particularly newly planted ones—may benefit from occasional supplemental watering.

A hose or other watering can might be a requirement once the irrigation system has been winterized.

Don’t Forget Evergreens

Evergreen trees and shrubs deserve particular attention heading into winter.

Unlike deciduous plants that lose their leaves, evergreens continue losing moisture through their foliage during winter. Going into cold, dry weather with adequately hydrated roots can help them handle our combination of wind, sun, cold temperatures and low humidity.

Give evergreens a good soil-moisture check before winter settles in.

A Simple Northern Nevada Fall Watering Rule

If you're unsure whether to water, don't make the decision based only on the date or the temperature outside.

Check the soil.

As fall slips into winter, water less frequently. Water deeply. Check newly planted plants more often. Watch the forecast. And don't assume the first frost means watering season is over.

Our high-desert climate doesn't always follow a tidy calendar—and your plants don't either.

Get Your Garden Ready for Fall

Fall is still a great time to work in the garden, whether you're adding something new or helping your existing landscape prepare for winter.

Stop by Bonsai Blue Garden Market in Reno to explore trees, shrubs, perennials and plants suited specifically to Northern Nevada gardens—and don't hesitate to ask us about caring for your landscape as the seasons change.

Happy fall gardening!