Best Garden Blog in Arizona?

Well, I'm amazed. Designing in the Desert has been nominated for the 2009 Blotanical Award of Best Garden Blog in Arizona. I'm honored and amazed. Thank you all so much, who voted so far. I've been working so much, I wasn't even aware of the awards or my nomination until another blogger sent me a congratulatory "tweet" this afternoon.

Which brings me to another point, the competition.... I don't have a chance.

Mo at Green Desert and Aiyana at Water When Dry both have excellent blogs. I enjoy reading them before any others and highly recommend them to you. They both have been much more faithful posters and great about sharing their lives and garden interests with us then I have been. ...And they both have better cameras, but I digress.

The other two, A Garden in the Desert and The Desperate Gardeners are both fairly strict garden blogs of the edible variety and where I like to visit when I'm in the mood for Az veggie garden info.

Never the less, I am fairly competitive. Since I don't have a chance at winning this thing straight up, I'm going to call on my enormous networking and Web 2.0 clan to create a landslide of votes and bury those two wonderful gals under tons of peat.
Four days left to buy votes.... Good luck Ladies! Bwa ha ha ha ha!

Step 2) Wetting the Root Zone

Ok, in this step we will discover how to properly cover and wet the root zones of your plants and trees. Not vertically like we did in the last step, but horizontally.

Remember, in the last step we figured out how many minutes it took to water your plants to the proper depth. Now we are talking width.

Why width? Because plants naturally send out roots to the drip line, or foliage line. The leaves and branches will naturally direct rain water away from the trunk towards the outside rim of foliage.

We want to place our emitters at about the same place to take advantage of the natural tendencies of the plant

Remember the illustration below? You can see how plant root structure stretch out from the trunks. We want to place emitters so the water wets as much of the root system as possible. We also want to encourage new plants to spread their roots out, as well.

You can also see how some larger plants will need more then one emitter, and trees can need numerous emitters to form health root growth.

In the drawing below, you can see a couple of examples of emitter placement as it relates to the canopy of plants and trees

The small canopy might be a small ground cover or accent plant like a Lantana or maybe Penstemon. One emitter wets a large amount of the root area.

However, when we move up to a larger plant, say a Sage or maybe Ruellia one emitter wets only a small part of the root area. At least two are needed.

You can see that even a small tree then can easily require eight or ten emitters to water the root area evenly.

Don't forget, as the plant or tree grows and spreads it's canopy, so do the roots. Your emitters will need to be moved out or new emitters added to evenly wet the root area and deliver enough water for the size of your plants.

Adding emitters to trees can be a real chore, especially if you're not experienced. I like to use the 5/8" drip tubing to loop around the tree and if you add an emitter every 2' to 2 1/2' you get a fairly even wet zone.

Here we have dug out a hole for a 15 gallon or 24" boxed tree. We have looped the tubing around the edge of the hole. the placement of the tubing is important because you must wet the root area that has been in the container, but also encourage the root to expand and anchor the tree. Right on the edge is perfect.

I like to use five 2 gallon per hour emitters on a 24"boxed tree. Four around the edge of the container and one on the base of the trunk.

You can use the smaller 1/4" tubing or "spaghetti" to fine tune the exact drip point where the water will enter the soil. Again, as this tree grows, you will need to move these emitters out and add a few more.

In this image you can see the emitter placed on the 5/8" tubing and the spaghetti leading up from it. The spaghetti tubing can be up to 10' long before you begin to lose volume.

Soil composition is important here also. The more dense or clay like your soil is the more the water will spread out as it percolates down to the roots. You may not need to add two emitters to medium sized plant because the water spreads out nicely. On the other hand, sandy soils usually require more emitters because the water doesn't spread much at all. It can run straight down with only a small wet spot on the surface.

We'll talk a little bit more about soils and also about irrigation timing on the next step.

Step 3) Cycle and Soak.

Rain Water Harvesting - The Good, the Bad and the Bunyips.

The Monsoons are supposed to be coming, hopefully. When they do, how much water will remain on your property? Will it cause problems on your property like flooding, erosion or foundation settling? If it happens to be a big rain, how long till you turn your irrigation system back on? Two, maybe three days?

I recently attended a very interesting seminar here in Phoenix. The topic was Rainwater Harvesting. If you live in Phoenix you may not know much about rainwater harvesting. We seem to have the attitude that water is cheap and plentiful, and it is thanks to the CAP. But this isn’t the case most everywhere else in Arizona. Tucson, for instance will be mainstreaming rainwater harvesting into their city development plans very soon. Starting this January all commercial projects in Tucson will have to provide 50% of the landscape irrigation through rainwater harvesting.

This is big news and no small step for any municipal water district. But what do you know about rainwater harvesting? Would you like to know more?

Well, the seminar was basically an introduction to an on line information module just now available for free through the University of Arizona, The Technology and Research Initiative Fund (TRIF), and The Water Sustainability Program. The actual module site was created by the Arid Lands Information Center team: Carla Casler, Theresa Crimmins, Damian Hammond, Chris Hansen, and Katherine Waser.

The goal of the site is to provide Arizonans who are new to rainwater harvesting with the tools and information they need to begin planning their own rainwater harvesting system. They discuss some of the most useful backyard water harvesting strategies, including some that you can implement yourself without a lot of expensive equipment or tools. They even offer a How-To video on Bunyips.

A bunyip is a mythical creature from Australian folklore, but also a very old and useful tool for grading. Personally I’ll stick with my laser level, but bunyip is such a cool word, I had to work it in.

You must register, but use of the module is free. Check it out: Simple Techniques for Back Yard Water Harvesting.

Have you ever noticed how happy your plants look after a good rain? It isn’t your imagination. Your plants prefer rainwater. I encourage you to get your feet wet (pardon the pun) and try a small project. If you have children, they will love it and it might get them away from the game console for a little while.

Landscape Irrigation without the Numbers – Step one.

Step 1) Discovering your watering rate:

Basically in step one, we want to figure out how many minutes it takes your system to wet the root zone of your plants.

First we need to let your yard or garden dry out a bit.

Then you will water it once for the normal amount of time.

Then you will measure the depth of the wetted area under your plants.

Let the soil in your yard or garden dry out for the regular interval between irrigation cycles, plus maybe one or two extra days. Watch your plants carefully. You may need to hand water certain plants, especially your pots and containerized plants that begin to stress.

When you are satisfied the ground is dry, or when many of your plants are beginning to wilt, turn your irrigation system back on manually for one cycle. Everything should get the normal drink of water. If your plants normally get 30 minutes, run it for 30 minutes. The best time to do this is early in the morning or just after the sun sets. Wait about an hour after the normal watering cycle is finished, then grab your soil probe. You are going to gently push it into the soil about 4” - 6” away from the drip emitter or bubbler of each plant. Remember, I said gently.

**** But first, a word of caution. ****

Every yard has utility lines, water, electric, phone, cable TV, natural gas and sewer. Add to that, landscape irrigation pipe and hoses, pool piping, landscape lighting, electrical for outdoor kitchen, patios, fountain pumps, drainage line, etc. Anytime you dig or push a soil probe into the ground, you should understand where these things are and take proper precautions not to hit any of them. There is a chance that you could make contact with an electrical line and receive a lethal electrical shock. Never use a hammer or anything to drive or pound your soil probe into the ground. Also make sure your probe is rounded or blunt on the tip. This way, if you do bump a drip line or pipe, your probe will probably slide off rather then puncture or cut the line.

Always call before you dig or excavate! Arizona Blue Stake will mark your utility lines in your yard for free.

The soil will be wet so the probe should push in easily. My wife can do this with one hand. If you have very little hand and arm strength, you might need to use two hands, but be careful. If the probe doesn’t go into the soil easily, don’t force it. You can move to the other side of the plant and try it, or move to another plant and try it again. I have been using soil probes for a very long time and I have never damaged anything. However, I use them very gently as if I expect I might hit a drip hose or pipe.

When the probe hits dry soil, it will be become harder to push it down. Don’t force it. You are measuring the depth of the wet soil only. Hold your finger, or mark your probe at ground level and then pull it out. This is the depth of the wet zone or soil reservoir your irrigation system has provided for your plant.

The 1, 2, 3 rule works well for mature plant root zones. Here in the desert, ground covers have a root zone about 1 foot deep. Shrubs feeder roots will usually run about 2 feet deep. Tree feeder roots usually run about 3 feet deep. Lawns should be watered to about 8”.

Adjust your timer till you have the right wetted depth for most of your plants. You don’t have to be perfect, just get close and write down your results. I usually make a simple drawing with the wetted depth for each plant along with the number of minutes used on the timer. This is very close to the amount of minutes you will use to irrigate each given zone or valve.

Don’t go out and buy a bunch or drip emitters and try to balance each plant just yet. In the next step we will talk about proper wetting of the entire root zone and balancing the water rate at each plant. You may need to change or add some emitters in this next step. That will be when you can go out and buy stuff.

Work through your watering depths and check back here for Step 2. Wetting the Root Zone.

Landscape Watering by the Numbers

Ok, it’s mid July and the Monsoons haven’t made much of an appearance yet. Recently we’ve had the hottest days of the year (so far) and some of your plants are probably looking a little sick. Many of us actually over-water this time of year because we worry about our plants out there suffering in this heat. So, in the spirit of hot air and since July is now Officially National Smart Irrigation Month, here is the beginning of a series on how to water your plants.

There are some pretty good guides and pamphlets out there that cover the subject very well.

This is the best pamphlet I’ve seen so far and you can download a PDF here.

The problem is these guides take time and to read and follow and we are all busy, right? Sometimes it’s just easier to add more time to the controller. And so this is how it happens that people get big water bills and many times sick plants from over watering.

Would you like a quick start guide? OK!

I have a fairly simple process that is part of a program I use on almost all of the properties where I manage the Landscape Irrigation. I have developed this process because everyone’s yard, garden and landscape is unique. Every yard is a micro-climate all its own. Plus the irrigation system is almost always different too. Sometimes they need some work, but I’ll cover that in another article.

However, the goal is almost always the same. We must deliver just enough water to wet the root area of the plant plus just a tiny bit of extra. Then to let the root zone dry a bit, then repeat. I’ll show you how to do that in your yard in three steps.

You will need a soil probe for this process. I think every gardener should have one. It doesn’t have to be spiffy. A very long screw driver or a piece of rebar with a point on one end works great. A three foot long soil probe is best, but a 24” probe can work. I use an old piece of rebar with a “T” welded to one end and grind stripes every 6”.

Here is a picture mine. It’s old and not real trendy.

You don’t need a “T” on the end. Rebar bent to an “L” on the end will also work great. I think almost any hardware store that sells rebar, sells shorter pieces and can bend an “L” on one end for you. Concrete installers use bent rebar all the time to brace concrete slabs. Very long screw drivers are cooler looking but they can be expensive.

**** A word of caution. ****

My soil probe is all metal. Yours doesn't have to be all metal. I have used all metal soil probes for many years without a problem. Used properly, they are about as safe as any other tool. However, there is a chance you or I could make contact with an electrical wire, conduit, irrigation line, sewer line, or water line that has been buried in your yard. There is a chance you could come into contact with a lethal amount of voltage. If you decide to use a soil probe of any kind, use it at your own risk. Never use a hammer or anything else to drive of force your soil probe into the ground.

In the next article, I will cover the proper use of a soil probe. Used properly, I believe they are about as safe as any other tool. There are some really cool soil probes on-line that range from $80. on up. There are a number with fiberglass shafts that should insulate you in the event you strike a high voltage line on your garden.

So go find one in the garage, build one or buy one and then come back for step one.

Will the REAL Mexican Bird of Paradise, please stand up?

I was thinking of Blooming Tuesday and set off on my morning appointment with camera in tow. Lots of plants are blooming in Phoenix right now and one of the most colorful are the Caesalpinia pulcherrima. So much color!

Notice the flower color and the leaf size.

Some of you right now are thinking, “Oh yeah, the Mexican Bird of Paradise. I love those”. Well guess what? This isn’t a Mexican Bird of Paradise. This is the actually the “Red” Bird of Paradise.

The distinctive element that separates this Caesalpinia from the others is the red flower color. Hence the common name, Red Bird. It grows to about 6’ and is root hardy to about 15 degrees. Although it likes to be cut back to 8” to 12” annually in the winter or very early spring.

There is a Pulcherrima “Yellow” Hybrid which makes it even more confusing. You'll see why shortly.

Since the Red Bird and Yellow Hybrid look pretty much dead or frost burned in the winter months, you will want to place it near or behind something that will be prominent during that time of year. I like to place them three or four feet behind boulders. Planting these right next to a sidewalk like above, probably isn’t the best location.

There are actually four Caesalpinias that are popular here in the Phoenix area; all of them are beautiful but, slightly different. Here is the next one.

This is Caesalpinia Mexicana

Again notice the flower color and leaf size.

The Caesalpinia Mexicana, the real Mexican Bird of Paradise is a larger plant, has larger leaves and can be pruned into a small tree up to about 12’ or 15’, is hardy to 18 degrees, and is a native to Mexico. Hence the name, Mexican Bird of Paradise. You can even buy them in 24” and 36” box containers now that the tree form has become more popular.

You can see some great examples of the “Mexican” bird of Paradise in the shopping center parking strip on the north east corner of Tatum and Shea. Hopefully they haven't been hacked up by an eager maintenance person.

One interesting use is in a partially shaded oriental garden. The Mexicana adapts well to shade and opens up into a beautifully delicate and graceful patio tree. This is the best I could do for a picture as this one hasn't been pruned and cleaned up. However you can see how the Mexicana responds to limited sun and how it will fit into a tight spot. The more shade the more open and to me, more graceful it will become.

Curiously enough some of you right now might actually be saying, Oh yeah, the Cascalote, I love that tree. Well guess what? This isn’t a Cascalote. Funny isn’t it. The Cascalote or Caesalpinia cacalaco is a slightly larger tree yet.

As you can see, they look very similar to the Mexicana. The leaves are a bit larger yet (impossible to see here), and the flower looks virtually the same, which is probably the reason for the confusion. However, if you look closely you will notice the bark is bumpy, thorny, and darker. Sort of a reddish-brown. They grow slowly to about 20’ or maybe a bit larger and are hardy to about 20 degrees, slightly more frost sensitive then the Mexicana.

There is another Caesalpinia and it is just as beautiful in its own way. The Caesalpinia gilliesii or Desert Bird of Paradise.

Again, notice the flower structure and color.

You can see this plant is similar in size to the Red Bird but, more open and graceful. The flower is yellow but, with very prominent red stamens. It grows to about 8’, is root hardy to 15 degrees and is a native to Argentina. Like the Red Bird, it likes to be cut back annually and re-grows fairly quickly.

I’m told that all parts of this plant are toxic. I don’t have any direct experience with this issue so I can’t advise you. People do grow and love the Gilliesii. Similarly I have heard that Oleander is said to be poisonous. However, I have planted, trimmed, pruned and probably even inhaled lots of it without a problem. I’m not sure how exactly the toxic issue with the Gilliesii manifests, but be warned, just the same.

All of the Caesalpinia are low water users and adaptable to part shade conditions. They like well drained soil so they are happy in the rocky and sandy soils found around greater Phoenix. The Mexicana and the Cascalote can make a great patio area tree in tight back yards, side yards and even entry ways. They are happy planted in full sun or part shade. Don’t expect everyone you talk to will know the difference. But you will.