Should Pine Trees be Grown in the Desert?

The major uses of pine trees in desert landscapes are for visual barriers, sun protection, windbreak, or mark property boundaries. 

Problems with Pines

They oftentimes become too large for the property. Cute when they are small. That is the problem now, they are large trees so you need a lot of space to grow them. And they use more water as they get bigger. And they need to be watered deep to improve their anchorage during strong winds. There are plenty of other choices that are smaller trees for shade and for visual barriers. As windbreaks? Put windbreaks close to where they are needed,  not on boundary lines.

Pine trees are frequently planted for shade but out of scale when they mature.

The two pine trees most commonly planted here, are the more formal looking Afghan (Pinus eldarica, sometimes called Eldarica or Mondell or Mondale pine) and the loosely structured and informal Aleppo pine (P. halapensis).

Aleppo vs. Mondell

The less formal looking Aleppo pine (P. halapensis)

The more formal looking, Christmas tree-like, Mondell pine (P. eldarica)

These can be fairly large trees at 40 feet tall and above and can easily dwarf a single story home. They can use quite a bit of space and, at those sizes, can use quite a bit of water when they get bigger. Its not a question about whether they will grow in the Mojave Desert but where will you put them?

Aleppo Pine Blight

They can look quite similar sometimes and telling them apart can be difficult. All pine trees can cross pollinate and are wind pollinated. But most of the time they are easy to recognize. One method I use to differentiate the two is the presence of winter physiological disorder called Aleppo pine blight. It only is present on Aleppo pine. It usually causes isolated browning of new growth in a patch or two here and there. In some cases, it can cause tree death but it is rare in Las Vegas.

Aleppo pine blight occurs during the winter and is a disorder that oftentimes causes isolated browning of new growth in Aleppo pine only. It can get so bad in some regions that it causes severe browning and suspected of tree death.

Chir Pine?

A vert large (60+ feet) and graceful pine sometimes used is the Chir pine (P. roxburghii). But this pine is a bit tender to winter cold (and in severe freezing temperatures (low 20's) can be damaged. Like many other plants, in its wild native habitat in the lower elevations of the Hindu Kush (northern India, Afghanstan and northern Paksistan) survives fire and will "sprout" new growth from its trunk if scaffold limbs are killed by fire or cold. Not to be confused with a very similar looking, long needled, but more winter tender pine called Canary Island pine (P. canariensis) heralding from...you guessed it...the Canary Islands.

Chir pine, considered perhaps subtropical, can be a bit tender in the Las Vegas area but it has a very graceful appearance if it survives the winter cold every 15 years.

Chir pine is one of the "long needled" pine trees that can have a very graceful appearance in the landscape but not nearly as tender as its very close relative, the tropical Canary Island pine and similar in cold hardiness to some of the more tender citrus like naval orange (P. canariensis)

This Chir pine survived but some of the branches froze. The mass of its trunk survived the freeze and sent out these suckers from epicormic buds embedded in the trunk. Fire and freezing temps can cause the same reaction.

Japanese Black Pine

Japanese Black pine is oftentimes recommended for planting in urban landscapes because it is a smaller pine (25+ feet) with an interesting form for landsapes. But when was the last time you saw one growing here? Nearly all of them planted here have died. Beware!

Japanese black pine.

Two Nevada State Trees

Bristlecone pine (P. longaeva) and Pinion pine (P. monophylla) are the two state trees of Nevada. Pinion pine occurs at around 4500 foot elevations in Nevada. Bristlecone pine much higher. For this reason, Pinion pine would  have a better chance in the hot, lower elevations of the Mojave Desert than the 6000+ foot elevation Bristlecone pine. Pinion pine occurs in the wild along with Utah juniper. The problem? Availability. It was popular for Mojave Desert landscapes about 25 years ago and disappeared from nurseries.

If you choose to grow pines in the desert:

1. Give them plenty of room to grow because they will be big trees.
2. Amend the soil in every direction around the trunk about 2 to 3 feet and a foot deep.
3. Cover the soil after planting with 3 to 4 inches of woodchips.
4. Water them with a coil of drip tubing or basin filled with water. 
5. Water them deep when you water - three feet deep!

Shade Cloth and Other Effects of Light on Plants

Sunlight can be very strong in the desert. In other parts of the country where sunlight is more "normal", shade cloth might not be needed. Desert sunlight can be very intense at times. It makes sense with some plants to reduce light intensity with shade cloth? But how much? Which plants?

Intensity

The effects of sunlight (or light) can be broken down into the quantity of light plants receive and the quality of this light. Light quantity refers to its intensity, or how strong this light can be. 

Intensity of sunlight refers to the quantity of light plants receive. Some vegetables give us better plant parts with a little bit of shade. This is 30% shade which is about right for a lot of leafy vegetables growing in the intense desert sunlight. This may be too much shade for some flowering vegetables like okra.

The 30% shade cloth was doubled over to give 60% shade in this darker area of the grow tunnel. Usually anything above about 40% shade will prevent a lot of vegetable growth and production.

Light Color

The color of light can also affect plant growth. Red light promotes flowering while solid blue light discourages flowering. Research has demonstrated that different colors of light in combination can promote certain types of plant growth. Should you as a homeowner use different lights? Probably not but it might be worthwhile if you grow plants commercially.

For more information look at https://sensing.konicaminolta.us/us/blog/can-colored-lights-affect-how-plants-grow/

At Dave Wilson Nursery near Modesto, CA, here red shade cloth is applied to influence plants.

How Long Light Shines (Photoperiod)

Plants will do different things sometimes at different times of year (mostly in cold climates, rain can play a similar role to light in tropical climates). Sometimes this is tied to how much night time there is or how much rain. Plants cant move around so they are much more "in tune" with their environment and "reading" it.

At this marijuana production facility light is used to provide the energy needed for plant growth. A certain light intensity is needed if any kind of production is needed.

Although not done here, a specific color of light could be used that enhances root production of these cuttings. Some decisions are better made considering the economics of production.

Crop Calendar for Yuma, AZ, USA.

 Yuma AZ is warmer than Las Vegas. Yuma sits on the border of Arizona and Mexico. Its latitude sits between 32 and 33 degrees North latitude (Las Vegas is closer to 36 degrees north of the equator). 

Yuma's elevation is only about 140 feet above sea level (Las Vegas is about 2000 feet above sea level). Both elevation and latitude play major factors in determining winter low and summer high temperatures.

Latitude and Longitude map of Arizona. Yuma AZ is near the border with Mexico and at 140 feet of elevation above sea level. Tucson AZ, even though lower in latitude than Yuma, is at 2400 feet of elevation above sea level which accounts for most of  its colder winter temperatures and warmer summers. https://www.mapsofworld.com/usa/states/arizona/lat-long.html

Because of its warmer winter temperatures, Yuma can grow some of the more tender nopales (such as Copena V1 and F1 and better tasting!) from Mexico than we can in our colder winters in Las Vegas. We can grow cold hardy nopales but they are not as tasty as the more tender Copena types. Winter freezing temperatures affect both pad (nopales, nopalitos) and fruit (tuna) production.

Freeze damage to Copena nopales growing in Las Vegas during the winter of 2007-8.

To make the planting/harvesting adjustment from Yuma to Las Vegas, consult local temperatures but it will be about 6 weeks forward in the spring months and about 6 weeks backward in the fall months.

Even though this crop calendar is for seed production, the planting dates would be the same.

 "Contracting" refers to the business arrangements needed for seed production to begin. "Sowing" refers to planting time.

https://www.condorseed.com/contract-production/ 

Are Food Forests the Right Thing to do In the Desert?

 Come join me in this podcast about exploring Food Forests in the Desert. Should we pursue this permaculture concept in desert landscapes?

Moringa leaves on our farm in the Philippines. We use the leaves of this tree for food and as a spice nearly on a daily basis. They are a commonly planted tree now in Southern Nevada due to food forests. But is it the right thing to do?