Water-Wise Gardening

Water-Wise Gardening

As Summer quickly approaches, and record heat and drought visit the West, water is on a lot of our minds. The years are getting progressively warmer, fire seasons longer, and water shortages increasing. Learning to garden with less water is not only time and money-saving, and more environmentally friendly, it's quickly becoming an essential skill for gardening in the West. It's not too late to plan for reducing water needs in your garden this year through a variety of simple means - accessible to any gardener.

1) Native or Climate-Adapted Plants

The first step to any water-wise gardening plan is choosing your plants wisely. Plants that are native to your bioregion are time-tested to thrive in your garden with little to no additional water needs. For example, in a Mediterranean climate like ours, many native plants are naturally-adapted to dry summers, and after establishment, require little to no water during the dry months. Whenever you can, consider a native plant when you make your garden addition - whether it be for food, beauty, or wildlife.

If you'd like to garden with non-native plants, no problem, just look to their water requirements first. Where do they grow naturally, and what is the climate like there? Don't just look for overall inches of rain per year, but seasonal distribution, as well.

Given the trends of climate change, many gardeners are taking their preparation a step farther, planting species from drier regions nearby. For example, here in Western Oregon, given the die-off or burning of millions of acres of Douglas Fir forest, some forward-thinking gardeners are considering Southern Oregon or Northern California native species for their backyards.

No one knows exactly what will happen, but we all need to think creatively about the best solutions for our local area.

2) Storing water in the Soil

Regardless of what you plant, the shape of your landscape and the structure of your soil make a huge difference in water retention (or lack thereof). Let's start with shape:

We all probably know that soil on hillsides drain water quicker than valleys. This basic principle applies to any ups and downs in your garden. A low spot holds water longer, a mound shorter. Creating small depressions or ditches for planting can allow you to get away with weeks less of watering. This is especially true if you can direct seasonal rainwater into these places directly. You might make small "irrigation ditches" diverting water run-off (i.e. swales), or simply planting closer to seasonal water sources that hold moisture longer.

Regardless of the ups and downs of your garden patch, the absolute best place to store water is in the soil itself. This might sound a bit odd, but different soils hold dramatically different amounts of water, depending on their composition. The most important and most affordable element to add to any type of soil is carbon - in the form of organic matter. Soils high in organic matter hold moisture much longer than those without.

There are numerous techniques for increasing organic matter in your soil. The most important first step is to reduce tilling or turning of your soil. Every time you till, you exponentially increase the breakdown and release of carbon, not to mention water vapor. The secret to less tilling is in the next section on mulch.

If you do decide to till, remember to mix compost back in every time you turn the soil. If you have time to wait till you grow in the soil, you can "compost in place" by adding straw and plant material and food scraps directly to a garden bed before tilling.

3) Mulch, Mulch, Mulch

Like so many sustainable gardening ideas, the idea of "mulch" is taken directly from the observation of nature. What does a forest do? It rains down mulch, and over time, creates a protective covering over the soil and all the life within it. Mulch is simply any organic matter that can be laid over the surface of the soil. It's doubly beneficial because it not only adds organic matter to the soil, increasing soil water retention, but it also shades and protects the ground, reducing evaporation. In addition, the microbes it protects loosen the soil for us, so much less tilling is needed.

The first mulch I also like to mention is the one people often think about the least: living mulch. All the plants in the forest are living mulch. They shade the soil and drop organic matter onto it. Generally speaking, the more plants you have in your garden shading the earth and putting living roots down into it, the better. This is especially true for perennial plants and trees, like those we sell here at the nursery. If they can form shade and living cover, they do much of the water-wise work for us.

This bit of knowledge can get us to plant more densely, like nature often does, and also help us to see the "weeds" a bit differently. Even though we dislike weeds in our gardens, (although many weeds are edible or medicinal), they are doing work of protecting and building the soil.

Regardless of plant cover, making a heavy mulch layer is essential for water-wise gardening. Consider what would naturally be mulch in your region. In Oregon, an easy option is woodchips. A little goes a long way, but we've experimented with depths of up to 18" for incredible soil building and water retention effects.

For those in drier areas, your mulch of choice could even be rock. Look under a rock during the heat of the summer in a dry area. It's often the most moist place you can find - that's why all the bugs and snakes and critters are hiding there! Plant a shrub next to a big rock and you'll be sure it's root zone will stay moist, and likely harbor some beneficial wildlife for your garden.

4) Drip Irrigation

Despite employing various water saving techniques, you may still find yourself needing to irrigate your garden. This is true even for a native garden the first few years. And when you do, the way you irrigate has a big effect on your water use overall, and on the plants themselves. Drip irrigation, though uses plastic, is often the most efficient and effective.

Drip irrigation uses small amounts of water in a specific location right at the soil over a longer period of time. This reduces waste and evaporation, and allows the water to enter deeper into the soil. This, in turn, encourages plant roots to follow it down, establishing deep root systems that make plants more resilient. Infrequent deep waterings train plants for future droughts and deficits.

Regardless of how you water, it's always most efficient to water when the sun's not out - generally overnight or early morning.

5) Rainwater catchment

Last, but not least, you might live in a climate where rain catchment makes a lot of sense. If your area gets irregular rains, catchment can help you provide water during the dry times. In our region with dry summers, we store water in cisterns for occasional watering during the long summer drought. This is especially true if you don't have access to a good well, or it's beginning to run dry.

This has been a brief overview of simple ways you can get wiser around water usage. Thanks for considering!  

(Photo credit: https://www.stuff.co.nz/life-style/homed/garden/112749516/sustainable-gardening-using-permaculture-principles)