Using irises in the garden

Our last post was about enjoying your irises; this article is about how to use them to best effect in your landscape design.

Pacific Coast irises can be a bit fussy if they’re not in their preferred coastal climate, depending on which species were used to breed them. Some species come from the foothills, and are a bit more adaptable inland – although you never know how the plants will fare until you test them in your garden.

Generally, irises do better on mounds if you have heavy soil. If your soil drains well, you can place them anywhere. Rich soil isn’t a necessity, and they seem to thrive in poor, gravelly soils where drainage is excellent.

If you’re lucky enough to live where native California species of iris grow naturally, you can pretty much plant them and forget about them other than enjoying the flowers every spring.

You can divide plants in fall, giving the plants time to re-establish themselves through winter and early spring. If you’re really in a native iris area, they may even reseed.

German iris are stars of spring, but virtually disappear in summer and fall during the dry season. It’s their way of adapting to their native Mediterranean climate – and what makes them so easy to grow in California. This makes using dwarf iris at the front of a border problematic, since the plants will fade away and need to be combined with something that lets the planting area look fuller in the drier seasons. The alternative is to have a spring garden full of a rainbow of irises of all colors and sizes that lives in a corner of the garden and simply goes dormant in summer to await the next season’s rains.

Other irises may or may not be Mediterranean. Dutch iris are bulbs and thrive here. Japanese and Siberian iris need constant water and prefer cool temperatures with higher humidity, so they may suffer through long, hot summers – or guzzle water.

Many species live in shallow water, so forget about using them in water conserving landscapes. One, yellow flag, is considered an invasive species in our waterways, so please don’t plant it in your pond.

Removing your lawn to save water?

Thinking of replacing your lawn? Take advantage of the situation to add color, interest, variety – and eliminate having to push around that lawn mower!

Hot lips sage

The Central Valley misses being a desert by only a couple of inches of rainfall per year – in a normal year. During the current drought, we’re well within the definition of a desert. Not the best place for a lawn more suited to cool, wet Northern Europe!

Since we’re in a Mediterranean climate, we don’t get enough rain to sustain a water-loving landscape in summer. High temperatures, low humidity and no rain make it impractical to store rainwater, if any.

The key to saving water while maintaining interest is to choose plants adapted to our climate – hot and dry in the summer, cool and wet in the winter – and our soils, typically heavy clay that does not drain well.

Before ripping out your lawn, you might want to consider why it’s there in the first place. Typically lawns are either play areas or what artists call “negative space”, a uniform color that sets off other elements, like a uniform color in a painting.

If you’re removing lawn, you might be able to add new functions to the space it occupied: sitting areas, hummingbird gardens, paths, vegetable areas, herb gardens.

You can add mounds, since you won’t be mowing your new plants. This lets you gain separation from the street, along with turning a flat landscape into something more interesting. The mounds can be accented with sculptures or rocks, too.

If you want the “negative space” look, there are some alternatives.

  • You can use native sedges such as Carex praegracillis for a grassy, green look. They’re taller than turf grasses, but the up side of this is you don’t have to give them as much water, and you can even integrate other low plants like yarrow and bulbs for a more meadowy look.
  • A local sod company has developed a blend of native grasses that can be put down the same as typical sod for an instant less-thirsty lawn. Once established, these grasses should use significantly less water than a traditional lawn, as long as your irrigation system is properly programed and in good working order.

If you’re creating more of a garden, plan on a mix of plant shapes and species, plant them in masses and think about the look you want to achieve. Remember to use low plants in sight lines from your driveway, limiting taller shrubs to areas where they won’t block views of oncoming traffic.

  • Trendy and modern designs can integrate agaves, desert spoon and red yucca with low shrubs and ornamental grasses. You can incorporate crushed rock paths, boulders, sculptures and l0w-voltage lighting to create something dramatic.
  • More English style gardens substitute water-loving shrubs and perennials for water-wise alternates: California fuchsia, native sages, ornamental grasses, lavenders, rockrose… all can create the effect of an English border without high maintenance or water needs. Bearded iris (and native iris) use little water since they grow during our normal rainy season, going dormant during the dry months.
  • If you’re looking for something more ecological, many California native plants can work well. You’ll have a variety of evergreen flowering shrubs of various sizes, perennials and grasses that often attract hummingbirds, feed native bees and are food plants for native butterflies. If you want to help Monarch butterflies rebuild their population, add some native milkweed into the mix – the plants are becoming more and more available.
  • Annuals and bulbs can work in more out of the way spaces. Although you can mix in some native grasses – like purple needle grass – for a bit of green year round, these plants will set seed and die, leaving you with a straw-colored landscape until the next season’s rains. Weeds can be a problem here, since they tend to blow in and smother your wildflowers over time. Despite the disadvantages, these gardens can be oases of color in spring, featuring California poppies, Farewell to Spring, baby blue eyes, Blue-eyed grass and others. The poppies and blue-eyed grass will go dormant over summer and pop up again with the next season’s rains; the other annuals will grow back from seed if all goes well. Mixing in native bulbs such as brodaiea creates even more variety.
  • Sometimes water conserving landscapes have an image of cactus, rocks, gravel and dust. True, most deserts have bare soil, gravel and rock – but they’re also a mix of plants, of which cacti are normally not the majority. So if you want to go the cactus route, mix them in with water-conserving sages, ornamental grasses and other plants requiring little water. Use agaves as accents, cacti as flowering plants. Avoid giant species like prickly pears and Century plant (Agave americana) unless you have a lot of room – and keep them back from paths where their spines won’t be an issue. Also, if you’re planning a succulent garden, pay close attention to frost tolerance and hardiness. A lot of these plants will freeze solid, especially aloes and newer hybrid agaves.

Done right, your new landscape will be much more interesting than the lawn it replaces, and be something you’ll cherish even after this drought is over.

This is one of those times that a design consult might help get you moving in the right direction. We can give you ideas for style, suitable plants, options and more. If you’re interested, please contact us to schedule a consult at your project site! (or click here for more information about consults).