GARDENING WITH NATURE

Article by Sigrie Kendrick

Use Fire-smart Plant Choices to Resist Wildfire

When designing landscapes in wildfire-prone areas, homeowners face the challenge of finding a balance between creating beautiful outdoor spaces while maintaining crucial fire protection for their homes.

Fortunately, several native plants offer both aesthetic appeal and FireSmart™ qualities.

Three standout choices, Mock orange (Philadelphus lewisii), Smooth Sumac (Rhus glabra), and Saskatoon Serviceberry (Amelanchier alnifolia) demonstrate that fire-wise landscaping doesn’t mean sacrificing beauty.

Visit the FireSmart website to learn about the best fire-resistant choices for your landscape.

MOCK ORANGE

Philadelphus lewisii, our native Mock Orange, is a deciduous shrub that typically reaches six to 10 feet tall, producing masses of white, fragrant flowers in late spring that evoke the scent of orange blossoms.

It earns its place in fire-smart gardens through several key characteristics–

• From a fire-safety perspective, Mock Orange excels because of its high moisture content and low resin levels. The plant’s broad, green leaves retain substantial water content throughout the growing season, making it less likely to ignite quickly.
• Unlike many ornamental shrubs, Mock Orange doesn’t accumulate significant dead material within its structure, reducing the fuel load when properly maintained. Its deciduous nature means it naturally drops leaves in fall rather than accumulating layers of dry, flammable debris as pyramid cedars tend to.
• Mock Orange responds well to pruning, allowing homeowners to maintain open spacing between branches that helps to prevent fire from easily moving through the plant’s structure.

Position Mock Orange 1.5 to 30 metres away from a structure where it can still provide privacy and beauty without endangering your home.

If you garden in a small space, consider the diminutive cultivar ‘Snowbelle’ which reaches only three to four feet tall and wide.

SMOOTH SUMAC

Rhus glabra, or Smooth Sumac brings both striking ornamental value and practical fire resistance to Okanagan landscapes.

This native shrub features compound leaves that turn brilliant shades of orange and red in autumn, followed by persistent crimson fruit clusters that feed overwintering birds.

Growing eight to 15 feet tall, Smooth Sumac spreads through rhizomes to form colonies, making it excellent for erosion control on slopes.

The fire-smart qualities of smooth sumac lie in its structure and composition–

• The plant maintains relatively high moisture levels in its foliage and stems during active growth.
• Its leaves are broad and flat, with smooth surfaces that don’t trap heat or encourage rapid flame spread.
• While Smooth Sumac does produce some woody material, it lacks the volatile oils found in many drought-tolerant plants.
• This species naturally self-prunes lower branches as it matures, creating vertical separation from ground fuels, a critical feature in fire-safe landscaping.

Regular maintenance enhances Smooth Sumac’s defensive qualities. Remove dead canes annually and thin colonies to prevent excessive density.

Space individual clumps of plants at least 10 feet apart to create natural firebreaks within your landscape.

SASKATOOON

Amelanchier alnifolia, commonly known as Saskatoon, is also suitable for planting along the perimeter of the intermediate zone, which is 1.5 to 10 metres away from a structure. It possesses several characteristics that make it a valuable addition to FireSmart™ landscaping.

This native Okanagan shrub is considered a fire-resistant plant due to its high moisture content in leaves and stems, which helps slow the spread of flames.

It maintains relatively lush foliage throughout the growing season, contributing to its lower flammability rating compared to many conifers or plants with resinous leaves.

Additionally, the Saskatoon can be pruned and maintained at a manageable height, allowing homeowners to keep it as a compact shrub rather than allowing it to develop into a taller bush, which could provide ladder fuel that may carry fire from ground level into the tree canopy.

When planted as part of a well-maintained FireSmart™ landscape with adequate spacing, Amelanchier alnifolia can serve both aesthetic and protective functions, offering beautiful white spring flowers followed by edible berries while contributing to a defensible space around structures in our wildfire-prone valley.

All three of these plants share critical FireSmart™ characteristics– high moisture content, low volatile oil production, deciduous habits that prevent excessive dead material accumulation, and growth habits that make them amenable to maintenance pruning.

Combine them throughout your defensible space, maintaining adequate spacing that prevents fire from jumping between bushes.

Remember that even fire-resistant plants require proper maintenance, such as regular removal of any dead material.

With these three beautiful fire-smart plant choices, you can create a landscape that’s both defensible from fire and drought-tolerant.

Sigrie Kendrick is a master gardener and executive-director of the non-profit Okanagan Xeriscape Association.

Use Native Plants to Create a Natural Garden

Article by Josh Smith, Xeriscape Endemic Nursery (XEN)

Consider transitioning a section of your landscape to native plants, where you can reduce both maintenance and water use, conserving a vital resource in this arid valley, along with your own energy.

A side benefit is that you are providing valuable feed and habitat for all sorts of indigenous wild things– from insects to birds, to small and large mammals– by your restoration.

Do not embark on this project unless you are prepared to accept that you are collaborating with your environment, not conquering it.

Rabbitbrush, Eericameria nauseosa

WHAT ARE NATIVE PLANTS?

Native vs Endemic vs Exotic vs Naturalized vs Invasive
The scientific definition of a native species is an organism that occurs naturally in a region without human introduction, having evolved there or arrived via natural dispersion over evolutionary time.

• NATIVE plants belong here.
• ENDEMIC plants belong ONLY here.
• EXOTIC plants are introduced by humans from elsewhere.
  *NATURALIZED plants are exotic plants that behave themselves.
  *INVASIVE  plants are exotic plants that are ecologically harmful.

CONSIDERATIONS FOR CHOICES

Consider first where a plant is native— Canada, B.C., or the Interior. Winter cold, summer heat, humidity/precipitation, and competition are all factors in limiting where exactly a plant is native.

Lots of plants native to B.C. are completely inappropriate in the Okanagan, so they’re unlikely to thrive here.

Then, within the Okanagan, first you must also consider whether a plant is native to our particular region of the valley; then, in which ecoregion it belongs: upland, riparian, high elevation, etc.

Further, consider whether it would thrive on a dry silty slope, a creek edge, or in a bed of clay.

Provenance (original seed source) and site matching (right plant, right place) matter more than just choosing a native plant.

Within the Okanagan, there are extremely diverse ecosystems in close proximity to each other, and ignoring sub-regional differences can cause failure unless you are careful to plant native plants in their natural environment.

Elevation, temperature, sun exposure, drainage, and soil texture often matter more than region.

In general though:

• The South Okanagan is hot and dry and of low elevation
• The Central Okanagan is transitional
• The North Okanagan is cooler and wetter

Pre-settlement landscapes in the Okanagan featured native plants that evolved with disturbance, not with watering, fertilizer, or mulch, such as we use on our man-made landscapes. This is a fire-adapted ecosystem that consists of drought-tolerant plant communities in patchy, disturbed, open landscapes.

Many native plants expect stress and respond poorly to pampering, so, as gardeners, we should take advantage of these attributes.

Showy Milkweed, Asclepias speciosa

ADVANTAGES OF NATIVE PLANTS

LESS WATER
The use of native plants in your landscape reduces the amount of supplemental water needed, but it does not necessarily mean they require no water. All plants require enough water when first planted to help them to settle in, so at least for the first year, they are likely to need some supplemental water over the summer and during drought.

LESS MAINTENANCE
Over the longer term, inputs such as fertilizer, replanting, chemicals and other maintenance are greatly reduced with native plants grown in a natural garden. Plants that evolved here are used to our weather swings. This is their home, and they are climate-resilient.

SUPPORT LOCAL ECOSYSTEMS
Native plants also support the local ecology, including pollinators, birds, mammals, and beneficial microorganisms, as well as their companion native plants.

Native plants overwhelmingly provide better habitat than non-native ornamentals and are the entry point for energy into our local ecosystem. They are the foundation of all food webs and feed everything, or everything’s food. Birds depend on insects as part of this food web: over 95% of land-based birds in North America feed insects to their young, and this includes species of birds that exclusively eat seeds as adults.

Birds cannot survive without insects, and insects are highly-specialized and often have evolved specific digestive enzymes and life cycles that require native plants as food or as a larval host for reproduction.

For an extreme example, the Okanagan has some species of butterfly that are at risk or endangered because they have evolved to only use one specific plant, or plant family, as a larval host.

Behr’s Hairstreak Butterfly depends on Antelope Brush; Monarch Butterfly larva can only survive on Milkweeds (Showy Milkweed is the only native here), and the Mormon Metalmark Butterfly relies on Buckwheats.

Human activity and climate change have reduced the population of these plants, which results in a reduced butterfly population, which in turn reduces pollination and seed production for these plants. This type of negative feedback spiral is often the cause of species extinction.

Pollinators also require native plants. Most ornamental, non-native flowers produce nectar that can be used by native adult bees as food, but the 500-600 species of bees native to BC are often pollen specialists that require specific plants or plant families for the pollen they need to feed their larva. Although the bees are very important, flies, other insects, and birds also do their share of pollinating plants.

In addition to pollination services, these insects and birds also often provide pest control, such as being predatory on pests like aphids.

GARDENING WITH NATURE

Article by Sigrie Kendrick

Creating Vital Food Sources

The Okanagan Valley’s unique climate and ecology make it a crucial habitat for both year-round resident birds and winter visitors.

By thoughtfully selecting and planting native trees and shrubs that provide food during the harsh winter months, homeowners and landowners can create vital food sources for local bird populations while maintaining our region’s natural biodiversity.

Snowberry (Symphoricarpos albus)

Landscaping Tips

Care and Maintenance

While native plants generally require minimal maintenance, some care during the establishment period ensures long-term success. Water deeply but infrequently during the first two growing seasons to encourage deep-root development. Avoid fall fertilization which may promote late-season growth vulnerable to winter damage.

Resist the urge to prune away all berries and fruits in fall cleanup. These food sources become increasingly valuable as winter progresses and natural food becomes scarcer. Similarly, leave some leaf litter under shrubs and trees, as ground-feeding birds often forage for seeds and hibernating insects in this natural mulch.

Beyond providing crucial winter bird food, establishing native plants creates year-round habitat value. These plantings support native pollinators during flowering periods, provide nesting sites in spring, and offer summer shade and shelter. As plants mature, they become increasingly valuable components of the local ecosystem, contributing to the Okanagan Valley’s biodiversity while providing endless opportunities for bird watching and nature appreciation throughout the winter months.

Check our Plant Database for more information on the plants mentioned above.

Sigrie Kendrick is a master gardener and executive-director of the non-profit Okanagan Xeriscape Association.

GARDENING WITH NATURE

Article by Sigrie Kendrick

It all starts with the seed

Whether you buy blooming plants and tall trees for your landscaping or plant seedlings and seeds—it all really begins with the collection of seeds from mature plants.

We all have the means to do that right in our own back yards. But, like so many things, it’s actually a bit more complicated than that. Working with Okanagan Xeriscape Association members and volunteers in the Xeriscape Demonstration Garden, we spent a couple of hours collecting seeds from the garden’s perennials and annuals. It’s a fun and inexpensive way to ensure the plants that thrived in their given environment this year will be around for future seasons.

As we were collecting the seed heads and labeling the storage bags, one of the volunteers peppered me with questions– How do you know when the seeds are ready to harvest? What conditions do you need to store them, and in what?

Quite a heated discussion ensued among everyone present, as, with so many gardening tasks, there is often more than one answer.

When and How to save your seeds

Annual and perennial seeds are ready to harvest when the flowers have finished blooming and the flower petals have turned brown or fallen off.

Collect the ripe seeds from the flower heads and lay them on wax paper away from sunlight to dry for a week or so. You can use a variety of storage vessels, plastic bags, wax, or paper envelopes. My personal favourite are the compartmentalized plastic containers my mechanic uses to store nuts and bolts and such.

Proper storage of your seeds will go a long way to keeping them viable for longer. Ideally, seeds prefer a dark, dry, cool environment between 35 F (1.6 C) and 40 F (4.4 C) with a humidity as low as possible.

While your refrigerator can supply the cool and dark environment, the high humidity inside is not ideal. If you do choose to use your fridge for seed storage, make sure to use airtight containers such as mason jars.

Wherever or however you choose to store your seeds make sure to label them properly, specifying the date and the plant from which the seed was collected. I can’t tell you how many times I’ve thought I would remember which seeds were which, only to scratch my head in the spring when I opened each compartment.

Many seeds benefit from a chemical change which mimics what they experience in their natural environment, such as freezing winter weather, burning temperatures or scarring or cutting from being exposed in the outdoors, or gnawed by an animal.

Scarification is the process of opening the seed coat and can be done mechanically, chemically or thermally in order to allow water inside the seed coat. Typically, this method is used on seeds with an extremely thick outer layer and is achieved unnaturally by scratching, filing, breaking, puncturing or burning the seed coat.

Stratification uses temperature to break the dormancy of the seed and it can be achieved by subjecting the seeds to periods of cold, either dry or wet cold. It is often achieved by storing your seeds in either the refrigerator or an outbuilding for several months.

One of the seed varieties that I’m most excited about is the Echinacea purpurea “Cheyenne Spirit” seeds, which we collected from the West Kelowna Xeriscape Spirit Square Garden. Many of the fancy new Echinacea cultivars have to be cultivated by vegetative means, and as such are expensive. Echinacea “Cheyenne Spirit” can be easily cultivated from seed and comes in a dazzling array of colours including red, purple, pink, orange, yellow and cream.

This xeriscape perennial has performed very well in the garden even during the challenges of severe water restrictions imposed during the summer season. I look forward to start propagating more of these tough beauties ready for purchase at our annual spring plant sale.

Check our Plant Database for more information on the plants mentioned above.

Sigrie Kendrick is a master gardener and executive-director of the non-profit Okanagan Xeriscape Association.