Ocotillos and visitors

So, the original idea here was to talk about how Ocotillo plants (Fouquieria splendens) in bloom seem to host bird or pollinator visitors at almost any time of day.

It seemed like a good idea to do at least one random sample of observation before declaring this.

And sure enough, during a 3 minute segment one spring afternoon, a few days into full bloom for the ocotillo, there were two bird visitors and several pollinator insects. Now this was just one casual observation, but it indicates how often you see creatures near or on these plants.

As noted in an earlier post, Verdins, (Auriparus flaviceps) the very small birds with yellow heads, are frequent visitors, apparently looking for insects. Finches are also common. And hummingbirds can be seen throughout the year.

It is amazing that any birds can find a firm foothold on the thorny stems. Clever feet.

Remember that the ocotillo is not a cactus, although it may look like one during some parts of the year. It’s in a completely different group. In fact, for most of the year, it looks like a bundle of dead sticks, and if you first saw one for sale in a garden center, you might wonder what they were trying to sell.

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Limiting factors in the desert

In some ways the term “limiting factor” is almost a definition of deserts, because deserts lack one or more essential ingredients for the survival of most kinds of plants and animals.

First, a desert is, by definition, a place with very little available water, either because there is little rainfall, or because it evaporates so fast. It may also be that most of the precipitation is unavailable because it is frozen most of the year, as in the far north or south, or in some high altitude regions.

Some areas may get bursts of moisture, even flooding, but it is episodic and not dependably available most of the year.

Temperature is another limiting factor. Many deserts get too hot for most organisms. Some deserts near the north and south poles are too cold. And yet others have wide swings in temperature.

Wind is another. There are few trees or shrubs to stop the wind. Desert mountains, river-courses or other sheltered areas may harbor small oases in their wind and sun shadows.

One unusual limiting factor is lack of sunlight. This can occur in deserts near the poles.

Especially interesting are the adaptations that plants and animals have developed to deal with these limiting factors. Many of them are what we talk about here.

Leafing again: the strange case of the ocotillo

One of the odder native residents of the Sonoran desert is the ocotillo bush. It typically consists of several spindly branches, vertically striped and spiny, up to 20 feet tall, that are leafless for long periods, only to sprout thick lines of small leaves within a few days after a rain.

Ocotillo branches with few leaves

Its desert adaptation of dropping leaves and playing possum is so complete that ocotillo plants for sale, in their leafless phase, with their branches tied in a bundle and roots bare, look thoroughly dead.

Ocotillo branches with many leaves

In the spring, they produce numerous red tubular blossoms at the ends of the branches that attract insects and birds of many species. They make great landscape plants because of their sparse sculptural look, and extremely low water requirements, and striking seasonal changes.

Choose native plants for your desert landscape

One way to figure out what plants will be suitable and attractive in your desert landscaping is to go to a nearby natural area and see what is growing wild.

Make sure you select a location that is similar to yours in exposure, dryness and altitude.

Take photos or make a list of plants you find attractive. Never dig up native plants! They are fragile and rare, and in most places it is illegal to do so.  Almost everything you will see is available in plant stores. Photos will also help you arrange your landscaping, showing which plants grow together, and how much space they need.

Then go to the web or in plant books to learn about the plants you have found, or take your photos to a local nursery that specializes in native plants, and decide which are for you.

The variety of desert plants is surprising: cacti, shrubs, vines, spring-flowering annuals, many kinds of perennials. A big virtue of native plants is that they  require little in the way of extra water and plant food, and are easy to maintain.

One thing to keep in mind about native plants–some of them grow very slowly, so it may take a while for your landscape to mature. But there is nothing to match their beauty, and their ability to attract native fauna.

Why does the cactus look like that?

The first thing you notice about a cactus is generally the spines. Some have short, nasty little almost invisible fishhooks, some inches-long needles. Then there’s the form of the plant. Most cacti are plump, rounded, often stubby. They tend to be grayish-green in color. And they usually do not have obvious leaves.

Why?

Whenever you come across questions like this, think about the ecosystem where the organism lives. Cacti live in dry climates with a lot of sun, and few other plants, especially leafy ones.

So keeping cool is an issue. A light neutral color does not absorb a huge amount of the sun’s heat. There are very few plants with dark bark, or skins, or leaves in the desert.

Retaining moisture is perhaps the most important issue for a desert plant. The blunt, compact shape of cacti, their thick skins, and lack of leaves are all moisture-conserving features.

And lastly, toothsome, moist leaves would attract all kinds of herbivores. So the lack of leaves discourages plant-eaters, and the big spines and tough hide protect any soft, moist tissue a cactus does have.

Plant your own desert landscape

There are obvious as well as more subtle things to consider when planting a landscape around your desert home.

Not surprisingly, the number one limiting factor in the desert is water.

Domesticated cactus

The number two limiting factor is shade. Some desert plants can’t tolerate any, some need it.

Other factors such as temperature, predators, and wind vary by specific location.

Interestingly enough, as well as enduring brutal heat, many parts of the North American desert reach temperatures below freezing at least a few days a year. The thorns and armor on many desert plants attest to their predators, ranging from insects to grazing mammals.

See what the experts have to say about useful and well-adapted plants that conserve resources:  www.amwua.org:plants_index.html

With a little knowledge, you can enhance your landscape naturally.