Permagarden

Check out this tour with Brad Landcaster showcasing this permaculture community outside of Tucson.

Desert Ecovillage Built for the Rain Brad Lancaster leads us on a tour of the Milagro Cohousing Community, completed in 2004. Milagro is located in Tucson, Arizona, and the design is centered ar...

Mistletoe (Phoradendron spp) gets blamed for killing trees. But these hemiparasitic plants don’t really draw much from their host plants. They even do a lot of their own photosynthesis. Trees that seem to be dying and are full of mistletoe are usually dying for other reasons. Mistletoe doesn’t take much more water from their host plants than plants growing nearby in the ground! But since many plant problems are not always visible and obvious, people blame mistletoe for the problems. And there are many people who make money pruning these out of trees and are financially biased. Mistletoe is an important plant for wildlife and they’re also just botanically interesting. When you see them in your plants, celebrate! And if you’re worried about your tree, focus on making sure it’s getting what it needs (usually proper watering is what is needed) …and lay off the pruners!

I ran into caleche when digging a planting hole for this Desert Ironwood tree. I didn’t want to plant the tree on a hard pan of solid caleche which is rock hard. I dug down a good 4ft and still found caleche. At this point I did a water test and filled the hole with water to test how well the drainage was. The water had thoroughly drained by the next morning so I felt comfortable planting the tree from there. I made sure to compact the backfill as I refilled the hole. Then I used a 6ft level to make sure the crown of the tree was not lower than the surrounding landscape. You can see this well by looking at the picture where I filled the basin with water upon planting the tree. Later I filled this basin with compost/ mulch. The end product is a heavily mulched, not-too-deep, seamless with the landscape tree. The broken up backfilled hole with great drainage will promote healthy deep root growth now that there isn’t a solid layer of rock like caleche in the way and the mulch will help retain moisture. All of this is in a basin that will hold water during an irrigation or rain event to store water that is applied faster than it can soak into the ground. AKA passive water harvesting.

A great desert tree, check it out!

When you see a desert ironwood tree (Olneya tesota) you know you are in the Sonoran Desert proper. Found in desert washes and on low hills, often in gravelly to silty soil, below 3,000 feet, the desert ironwood's range is identical to the range of the Sonoran Desert, proper. The only other organism that has such an identical range is the lesser long-nosed bat.

Desert ironwood is also a habitat-modifying keystone species, that is, a species that exhibits strong influences on the distribution and abundance of associated species. It is important as a nurse plant for many younger plants--providing shade and protection as they grow, as well as providing habitat for animals that make nests in the trees, as well as below the trees.

Possessing one of the hardest and heaviest woods in the region, desert ironwood grows slowly but steadily, and some trees are estimated to be about 800 years old! It is remarkably resistant to rotting, perhaps because its heartwood is rich in toxic chemicals that make it essentially non-biodegradable--a dead ironwood tree trunk will persist as long as 1600 years!

Usually a multi-trunked tree, sometimes single-trunked, plants can grow as large as 50 feet tall, but normally much shorter, especially in Arizona. More commonly in our area they get up to about 30 feet tall and wide. They bloom in April - May and are followed by seed pods. Native bees are the primary pollinators of ironwood. The tree is also a larval host to the Rawson's metalmark (Calephelis rawsoni).

For information on using ironwood as food (especially the seed) check out Desert Harvesters page on Ironwood.

Grow ironwoods in full sun with moderate to low water. It is hardy to about 20º F. Ironwood is slow-growing if you rely on rainfall, but on irrigation it grows much faster.

While Ironwood is not endangered or threatened, its populations dwindle annually over tens of thousands of square kilometers.