This document discusses water zone (hydro-zone) gardening, which involves grouping plants together based on their water needs. This allows a gardener to save water by reducing irrigation in some areas while providing each plant with the water it requires. The document outlines four water zones based on annual precipitation: zone 1 for little to no irrigation (<10 inches/year), zone 2 for infrequent water (10-20 inches/year), zone 3 for occasional water (20-30 inches/year), and zone 4 for regular water (>30 inches/year). It provides examples of plant types and suitable irrigation methods for each zone. The document encourages gardeners to analyze their yard conditions and existing plant water needs to determine the best layout of

1. Save Water using Water Zone (Hydro-zone) Gardening
Water is becoming scarcer in many parts of the Western. As precipitation patterns change, and
more years are characterized by drought, water use priorities will need to adjust. We need to
plan for using less water for garden irrigation. One good way is to apply the principles of Water
Zone (Hydro-zone) Gardening - grouping plants by their water needs. This allows you to save
water in some areas of the garden (the dry zones) while giving each plant the water it needs to
thrive. And it allows you to make best use of natural precipitation. If you don’t know what your
yearly precipitation is, a good Colorado resource is: http://perg.nau.edu/datamap.htm
Our gardening philosophy here at Mother Nature’s Montrose Garden is a practical one: work
with what you have. It’s much easier to treat your garden’s characteristics as assets – positive
attributes – rather than limitations. Your garden’s physical assets (sun; shade; wind; soil
characteristics; etc.) are the canvas on which you paint your garden. Your garden’s assets give
your garden its character and shape. They also help keep our ‘excessive tendencies’’ in line
(yes, we all have those tendencies – we’re human, after all)! So, view the need to reduce your
garden’s water use in a positive light. Water Zone gardening can re-make your garden into a
more interesting and inviting place for your family (and many other creatures) to enjoy.
Water Zone gardening involves conscious choices on how to ‘spend’ your water budget. For
example, you may choose to spend more water on your vegetable garden or fruit trees and less
on your lawn. It also requires you to study and work with the conditions in your yard. Water
Zone gardening involves choosing the right plants – and watering methods – for each Water Zone.
Water Zone gardening is not difficult, but it does require some thought and planning.
In a garden planned around Water Zones, plants with similar water needs are grouped together.
Where possible, plants requiring less water are planted in parts of the garden that are naturally
dry – or are difficult to water. Plants that require regular water, also grouped together, are ideally

2. planted in areas that are naturally moist. And then there are areas that fall somewhere in
between.
Lower elevation Western Colorado gardens (< 7500 ft. elevation) have four basic Water Zones.
Each is slightly different in appearance – and each is interesting and beautiful. You will likely
want to use all four in your garden.
Zone 1: Little/no
irrigation.
< 10“ total water per
year
Description: Most water obtained from rainwater, except in years with very dry
Winter/Spring conditions. Many native plants, including shrubs, will be summer-
dormant; ornamental grasses turn golden-brown. Annual wildflowers & bulbs
disappear.
Colorado Places with this level of yearly precipitation: The valleys of Western
Colorado including Delta, Fruita, Grand Junction, Montrose
Garden Examples: Non-planted areas (patios; walkways); naturally dry areas or
shady areas that remain moist for long periods; areas planted with low-water
ornamental grasses & wildflowers; areas planted with the native plants of Western
Colorado valleys.
Watering: Plants mostly get by on rainwater; dry season irrigation only during
prolonged dry spells (4 or more weeks with no rain). Established plants watered
only 1-2 times in summer, if that.
Suitable plants: Once established, many western Colorado native plants from
elevations < 6000 ft. can be treated as Zone 1 or Zone 2 plants; desert and steppe
plants from Four Corners states.
Best watering methods: Easily watered with garden hose; water deeply.

3. Zone 2: Infrequent
water
10-20” total water
per year
Description: Plants receive infrequent dry season irrigation, particularly
during prolonged dry spells. Plants range from perennials to large shrubs &
trees.
Colorado Places with this level of yearly precipitation: Cedaredge, Colorado
Springs, Cortez, Craig, Denver, Dove Creek, Glenwood Springs, Gunnison,
Meeker, Naturita, Norwood, Paonia, Rifle.
Examples: Water-wise groundcovers/lawns; many plants advertised as
‘water-wise’ or ‘xeriscape’ plants; some established trees and large shrubs
(even some non-native), particularly those with deep root systems.
Watering: Dry season irrigation only when soils are dry at a depth of 6 inches
(dig down to check). Sandy soils often watered 2-3 times a month in dry
season; clay soils may only need water twice a month. Soils are watered
slowly and deeply – may take several hours to water adequately.
Suitable plants: Most plants labeled ‘water-wise’, including many Colorado
and Four Corners natives from 6000-8500 ft elevation (note: these plants will
need more water during first year or two until plants are established). Local
native plants (from western Colorado) are particularly well-suited to Zone 2.
Examples would be species of Ericameria, Pinyon pine, Utah juniper, native
grasses, grass mixes labelled ‘low water grass’, and many others.
Best watering methods: Water using low-flow sprinklers, soaker hose/soaker
tape, micro-sprinklers, drip irrigation or garden hose. Water early morning or
late in the day.

4. Zone 3: Occasional
water
20-30” total water
per year
Description: Plants receive occasional dry season irrigation, particularly
during prolonged dry spells. Plants range from perennials to large shrubs &
trees.
Colorado Places with this level of yearly precipitation: Aspen, Evergreen,
Ridgeway, Silverton, Steamboat Springs, Telluride.
Examples: Water-wise groundcovers/lawns; established trees and large
shrubs (even non-natives), except those from riparian plant communities.
Plants that naturally grow in the above mentioned Colorado places.
Watering: Dry season irrigation only when soils are dry at a depth of 6 inches
(dig down to check). Sandy soils often watered weekly in dry season; clay soils
may only need water 2-3 times a month. Soils are watered slowly and deeply
– may take several hours to water adequately.
Suitable plants: Many non-native shrubs and perennials sold in local
nurseries; many plants labeled ‘water-wise’; Colorado and Four Corners
native species that grow at elevations of 7000+ ft. elevation (note: may need
more water during first year or two until plants are established). Local native
plants from higher areas of the Uncompahgre Plateau and local mesas are
particularly well-suited for this level of irrigation, and look good with a little
more water than they get in the wild. Examples would be species of mountain
spruce, juniper, and many others.
Best watering methods: Water using low-flow sprinklers, soaker hose/soaker
tape, micro-sprinklers, drip irrigation or garden hose. Water early morning or
late in the day.

5. Zone 4: Regular
water
30-40+” total water
per year
Description: Regular water during dry season; soils are moist/damp year-round.
Plants may be evergreen or winter dormant.
Examples: Sod lawns, rose gardens, vegetable gardens; plants around garden ponds;
plants from Eastern and Southern U.S. and from Pacific Northwest.
Watering: Plants are watered from spring (when soils dry out) to fall (when rains
saturate the soil). May need daily water during dry, windy periods. Check soils – if top
1-2 inches are dry, then you need to water.
Suitable plants: many common nursery plants – most will be labeled as needing
‘regular water’; plants that normally grow in moist soils around lakes, on stream banks
or in bogs or seeps; mosses; cattails, willows, rushes and sedges.
Best watering methods: Water with multi-stream rotator/rotor sprinklers or shrub
heads in the early morning or evening. For larger areas, impact rotor sprinklers give
larger area of coverage. For greatest efficiency, choose sprinkler heads that produce
droplets, rather than spray.
Getting Started
The key to efficient water use is working with the conditions in your yard. Take a good close
look at your entire yard. Often the easiest place to start defining Water Zones is with areas that
are naturally dry. Are there places that seem to always dry out or are difficult to water?
Consider working with Mother Nature by converting these areas to Water Zone 1 or 2. You can
plant them with drought tolerant plants and decrease your overall water use. You may even
discover areas that could require no water at all. For example, you might convert a difficult-to-
water area into a patio, sitting area or utility area. Use bricks set in sand or a gravel mulch as
hardscape and you now have an area that needs no water and infiltrates rainwater as well.
Do you like/have plants that require regular water? The next easiest areas to define are those
that require regular water (Water Zone 3 areas). You may have a rose garden or other special
plants that need water. You may have a lawn area. Or you may want to plant a vegetable
garden. By grouping plants you’ll be able to provide Zone 3 plants with the water they need in
an efficient manner. You can focus intensive watering efforts on these areas – and choose an
irrigation system that fits your needs. You might consider planting Zone 3 plants next to a lawn,
near a water feature or at the bottom of a slope where they get a little extra water. Learn to
work with Mother Nature! Use naturally wet areas of the garden – like shady areas – to your
advantage.
If possible, you’ll want to locate Zone 3 and 4 areas away from Zone 1 areas. The water needs
of Zone 1 and 3 or 4 plants are very different, so it’s best to separate them by areas of Zone 2
plants or hardscape (non-planted areas). Water Zone 2 is probably the most interesting Water
Zone in most gardens. Many exotic, fragrant and beautiful local native plants can be treated as

6. Zone 2. In nature, these plants get by on rainwater alone. In the garden, they look better with
occasional summer water. Just be sure to let the soil dry out in Zone 2 and 3 areas between
deep waterings. Many plants from the Four Corners States are most comfortable in Water Zone
2. They do well in transition areas between Water Zones 1 and 3.
Get to know your plants better. Many nurseries, including native plant nurseries, provide
information about water needs for individual plants (read the labels carefully). Consider the
water needs of each plant before you purchase it. Visit water-wise and native plant gardens for
inspiration and information. Use the Water Zone information on our garden’s plant signs to
help you choose plants that are right for your garden.
In summary, the trick to saving water is to view your yard as containing several different
‘gardens’, each with its own water requirements. Using Water Zone principles makes this
possible. Creating areas that get ‘less than regular’ water allows you to use plants that actually
require less water. You can spend your ‘water budget’ on the plants that matter most to your
family, save money and create a more interesting garden – all at the same time!
You can e-mail your Water Zone questions to: monaturesmontrosegarden@gmail.com