Water-Wise Gardening Tips

It’s dry out there. We had pretty good moisture over the winter months, but the early spring has been unseasonably warm (OK!) and dry. We’ve come to expect that in New Mexico, and a few days ago, I wrote about the wildfire danger. Today, let’s review a few tips for water-wise spring landscaping that help homeowners here and just about anywhere in the country where drought can be an issue.

  • Set out your rainwater harvesting system. If you live in a climate zone that’s warm enough to leave rain barrels out all winter or have underground cisterns, your system has been efficiently gathering water all winter. In other climates, rain barrels can freeze in winter. Ours are on the south side of the house and should be past danger of long and hard freeze. Now, all we need is rain.
rain barrel in New Mexico
A simple rain harvesting system that came as a kit. All we had to do was shorten our downspout.
  • Update your irrigation system to a low-volume method. The most practical and water-efficient way to hydrate ornamentals is with drip irrigation. When you use spray heads, water evaporates into the air. It also hits leaves and nearby plants. The spray can cause leaf disease in some plants, plus it’s more efficient to soak roots deeply than to water the entire plant.
  • As you plan your irrigation, or check out your current system this spring, make sure to adjust the water amount for the plants or areas where you have bubblers. For example, succulents and many xeric plants need no water at all once established, unless you’re in an extreme drought. You can cap those bubblers off. Too much water can actually harm some xeric plants. Use drips at the base of low- and medium-water flowers and groundcovers. Increase the flow rate for larger shrubs and trees, and add a few extra emitters around trees, especially while they’re becoming established. Remember that tree roots grow out, just like the canopy.
drip system for xeric gardening
A drip system irrigates rosemary, yucca and other plants in this xeric garden.
  • Water in the morning to get your plants through the heat of the day, and when less evaporation occurs.
  • Use raised beds. Raised beds and containers concentrate water, so if you want a few herbs or vegetables or some medium- to high-water ornamentals, confine them to an area that takes a little more water than the others. If you place the raised bed near your drip system, you can add it to the mix and adjust the flow on your emitter if necessary. Just remember, some containers, such as clay pots, dry out more quickly, even though they use less water each time. It’s like having a smaller tank on a fuel-efficient car. It’s not necessarily using more gas, just needing more frequent refilling.
  • When adding plants to your garden, build a small well around them to hold water. This helps the plant soak up the irrigation and keeps water from running down and off the plant, wasting your precious resource.
well at base of tree
This well helps hold water until this small tree is established, especially since it’s on a slope.
  • Use mulch when possible to help retain water and keep roots cool during the heat of the summer.

Finally, automatic irrigation is most efficient, and the consistent, timed watering is best for plants and lawns. But override it whenever you can after a good rain. I used to bemoan the waste when my neighbor’s sprinklers would come on as scheduled while their lawn already glistened with rainwater.

deer in xeric garden
Most of the plants in our xeric rock garden receive no irrigation, just supplemental watering to establish new plants or an occasional drink during drought.

How To Read Plant Label Codes for Watering Needs

Plant tags, labels and catalogs are much more attractive if they use icons instead of text instructions. Much like infographics, it’s a newer direction in communication. I see the good side of it, especially for people who have low literacy or shop with small children and don’t have time to turn the tag around for more information. I could say the drawback is that the more we put in symbols, the less we need writers, but that’s not a rant for this blog post.

As far as I know, water symbols are not standardized. If I’m wrong, I would love to be corrected. I think a standard nomenclature and symbol system for plant watering would be a great service to gardeners.

plant-catalogs-labels
Catalogs, seed packets and plant labels use a variety of methods to give us clues about a plant’s water needs.

Most water requirements are represented by a water droplet symbol that’s empty, partially filled or completely filled. My summary of similar legends, like the one used by the Albuquerque/Bernalillo County Water Authority, provides the following clues to irrigation:

Empty drop: A plant that requires only rainwater or no supplemental watering once established. So be sure to give a new or transplanted tree or bush extra water until it appears healthy. This can be up to a year for trees and some bushes. After that, there’s no need to irrigate the low-water plant at all. Half-filled drop: This is a medium-water plant. It will always need some supplemental water, depending on what Mother Nature delivers. Most medium-water plants need supplemental water once or twice a month during the hottest days of summer.

seed-packet-water-drop
This seed packet shows the moderate water needs of a sunflower.

Full drop: I am not familiar with these plants. Seriously, they usually aren’t going to make it in places that deliver little rainfall, and if they do, it’s not water-wise gardening. But they often can survive in the right climates and conditions, maybe in a welled spot or container, or where there’s run-off from a streambed. Of course, if you live in a tropical area, that’s just not fair. There are additional variations on these labels, like partially filled drops. I’ve also seen use of watering pails as symbols. Most add text alongside the icons, but if in doubt, ask for help from the nursery staff or a local master gardener.

portulaca-bloom
And because I have to include a pretty flower picture, here’s a portulaca bloom. I love these low-water heat lovers.

No matter what the label shows, circumstances can affect water needs, so don’t take your water icon at face value! Aside from plant establishment, wind and unexpected heat waves can dry plants out. Summer monsoons can nearly drown our drought-resistant plants! And welling and mulching around plants helps them retain water, maybe helping you push a half-filled drop to a quarter-filled one…

Xeric Garden Zones

If you’re planning a xeric garden for spring, and especially if you’re planning to take out a grass lawn and replace it with gravel and xeric plants, try planning your garden in recommended water zones.

First, let me jump on my gravel soap box. I’ve said it before and I’ll say it every chance I get: Ripping out grass and replacing it all with gravel represents many homeowners’ idea of xeric gardening. They soon find out that it’s not the best solution when a tree left in the middle of a gravel lawn dies and their home cooling bill skyrockets.

gravel yard
A typical gravel lawn misnamed as xeriscaping. Note the grass creeping up between the gravel, but that’s a future topic.

So let’s consider zones instead.

Arid Zone

You’ll want your most arid zone farthest from your house. Choose native plants that need the least amount of water, hopefully no supplemental watering at all. Here in New Mexico, that might include cacti, yuccas and many varieties of native flowering plants like Kniphofia uvaria (Red hot poker) or Berlandiera lyrata (Chocolate flower). It all depends on your landscape and personal preference.

Cacti-gravel
Cacti can add texture, height, blooms and plenty of interest to an arid zone.

Transition or Middle Zone

Your next zone can blend some lush, medium water areas with drier ones. Here’ you’ll use plants that take low and medium water. They only need water beyond nature’s supply about once a week or less. It’s a great spot for medium-water shrubs and trees, such as Spartium Junceum (Spanish broom) and various native oaks to provide summer shade, but let winter sun shine through.

This lawn is not a perfect depiction of the transition and mini-oasis, but it shows the arid zone with low-water plants, and a Bermuda lawn. Note the unhealthy cypress, planted years ago.
This lawn is not a perfect depiction of the transition and mini-oasis, but it shows the arid zone with low-water plants, and a Bermuda lawn.

Mini-oasis Zone

If you want to keep some grass, here’s your chance. Drought-tolerant grasses like Bermuda, Blue Grama, or Buffalograss need little watering but keep your lawn green and other plant roots cool. When used in moderation, and not to cover huge areas, they’re still low- to medium-water choices for this zone. Add some annual flowers in beds or containers up close to the house. By placing lusher plants and turf that need a little more water closer to your home, you help cool your house and take advantage of water runoff from the roof and downspouts.

xeric landscaping zones
A simple example of xeric water zones.

Of course, the drawing simplifies the concept. Landscapers who understand xeriscaping concepts know how to make your zones appealing and customized for your tastes and gardening ability. And by using microclimates, mulching, welling and other waterwise concepts we’ve discussed in other posts, you can push the limits in some of the zones. The basic concepts are to keep from overusing water and avoiding undermining the health of existing trees, along with the comfort and appearance of your home.