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Have you ever made a discovery that was literally under your nose?  

I did.

Earlier this month, I embarked on a tour of low-water gardens that displayed sustainable design throughout the greater Phoenix area.  

The earlier parts of our tour showed examples of water harvesting using cisterns along with man-made arroyos.  Then we viewed a creative example of sustainable design for a beautiful parking lot that needed no supplemental water and little to no maintenance.


I mentioned last week that I had saved the best for last and I can’t wait to share with you this jewel in the midst of a desert city.

The last stop on our tour of low-water and sustainable gardens was the Scottsdale Xeriscape Demonstration Garden.
 
The garden is just over 5 acres and sits hidden from the street next to Chaparral Park in central Scottsdale.

Over 200 different types of plants are used throughout the garden, all of which are drought-tolerant and well-adapted to our hot, dry climate.
 
My friend and fellow blogger, Pam Penick, came with me to this beautiful garden (you can see her at the top of the terraced planters).
 
One of my favorite parts of the garden included this innovative design, called the ‘Terraced Cascade’ which creates the appearance of water traveling down between terraced planters filled with Palo Blanco trees (Acacia willardiana) and Desert Marigold (Baileya multiradiata).  
 
 
 Water does flow down discretely hidden steps between the terraces during times of heavy rainfall toward the water harvest basin where it waters existing plants before flowing underground toward the nearby lake.
 
 
Raised planters were filled with flowering Ocotillo  as well as Birdcage Evening Primrose (Oenothera deltoides).
 
Birdcage Evening Primrose (Oenothera deltoides) in the foreground and Mexican Evening Primrose (Oenothera berlanderi) growing against the Ocotillo.
I must admit that I was surprised to find this garden in an area that I used to spend a lot of time in.
 
Years ago, before the garden existed, my husband and I would take evening walks around the nearby lake with our daughter.  Believe it or not, before there was a garden, there used to be a miniature golf course in this location. 
 
 
I love stone walls and would have some in my own garden, if I could afford them.  The stone walls were capped with flagstone and had rows of round stones, which added an unexpected touch of texture.  
 
 
From our vantage point, we could see to the other side of the garden where a tall, dead tree stood.  Trees like this are called a ‘snag’, which is a dead or dying tree.  This tree provides a home for hawks, which help keep the rabbit population down. 
 
Baja Fairy Duster (Calliandra californica) and Desert Marigold (Baileya multiradiata)
Gabion walls were used along pathways to created terraces to help slow down storm water in order to reduce flooding while watering the plants.
 
The demonstration garden is located next to a water treatment plant and part of the garden sits on top of a reservoir that contains 5.5 million gallons of treated water.
 
Deer Grass in the foreground.
 
One of the things that I enjoy about demonstration gardens is that they ‘demonstrate’ different gardening methods as well as showcasing plants.
 
In this case, I was impressed with the collection of plant species used, which aren’t typically seen in residential or commercial landscapes, which is a shame.
 
 
As we walked down the main path, we came upon a man-made, mesquite ‘bosque’.  The word ‘bosque’ is used to refer to stands of trees nearby rivers or washes throughout the southwestern United States.  Usually, you’ll find these bosques made up of mesquite trees.
 
This bosque was planted with Honey Mesquite trees (Prosopis glandulosa), which is simply stunning in spring when it’s bright-green leaves reappear.  A warning though – it has thorns.
 
Palo Brea (Parkinsonia praecox) trees and gabion walls line the main walkway.
 
Plants are maintained just the way I like them – no shearing or over-pruning.  
Gold Mound Lantana, Orange Bush Lantana and Pink & White Globe Mallow.
 
The main pathway parallels the local dog park.
 
 
There is little that can compare to the beauty of the  new spring leaves of mesquite trees.  I love how the coral-colored variety of Bougainvillea and the yellow flowers of Aloe Vera look like brightly-colored jewels along with the leaves of the mesquite.
 
 
Nearing the end of the trail, I couldn’t help but marvel at this beautiful garden and its creative design.
 
Throughout the garden were educational signs talking about a myriad of gardening subjects that were clearly illustrated by the garden itself including planning and design, plant care and desert habitat.
 
 
A large cistern was located on one end of the trail, which was filled with the average amount of water that a household uses in 1 week.  
 
Around the outer border of the cistern is an American Indian saying that says:
 
“THE FROG DOES NOT DRINK UP THE POND IN WHICH HE LIVES”
 
Those are words that all of us who live in the dry, southwest should all ponder…
 
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The Scottsdale Xeriscape Demonstration Garden is located at Hayden and McDonald Roads in Scottsdale.  It is open from sunrise to 10:30 at night.
 
I hope you have enjoyed these posts of our tour of sustainable, southwestern landscapes in the greater Phoenix area.
 
Pam and I drove about 170 miles in one day and we weren’t able to see all of the great examples of sustainable landscaping.  However, if you are interested in seeing examples of sustainable gardening, then I would recommend starting at the Desert Botanical Garden, which is filled with arid-adapted plants that thrive in our climate with minimal water and fuss.
 
If you haven’t visited Pam’s blog, Digging, I encourage you to do so.  Many of the plants that she grows in Austin do well in our climate too.  Did I also mention that she is an author?  She has a fabulous book called Lawn Gone!: Low-Maintenance, Sustainable, Attractive Alternatives for Your Yard, which I highly recommend.
Desert Botanical Garden Plant Sale
 
I enjoy attending plant sales hosted by botanical gardens.  
 
Here in the southwest, you can often find the newest succulents including those that are hard to find as well as old favorites.
 
There are a few tips that I’d like to share with you the next time you are buying a succulent whether at a plant sale or your local nursery that can save you money.
 
 
1. Avoid purchasing agave in 15-gallon containers or larger.  
 
Why?  Well, almost all species of agave will flower toward the end of their life and then die.  That is what agave do.  
 
Flowering is triggered by the age of the agave.  Different species live for differing lengths of time – some live less then 10 years. If you buy a 15-gallon or larger boxed agave – it is safe to assume that they are much older then those in smaller pots and will flower and die much sooner.
 
So my advice is to purchase agave in 1 or 5-gallon sizes – they will last much longer and you’ll save a lot of money.
*Sometimes, you can find more then one agave growing in the same nursery container – that’s like getting 2 for the price of 1!
 
 
Better yet, ask a friend or neighbor for a volunteer (pup) from their agave.  Many agave species produce volunteers that can be transplanted.  To learn how, click here.
 
My husband and daughter checking out the young saguaro cacti.
 
2. Buy smaller cacti rather then larger.
 
Columnar cacti are beautiful, but expensive.  The price is usually based on the height of the cactus.  Saguaro cacti are priced based on each foot in height plus arms.
 
The price for a 1 ft. high Totem Pole cactus was $48.
 
The reason that I recommend starting out with a smaller columnar cactus such as Mexican Fence Post (Pachycereus marinatus) or Totem Pole (Lophocereus schottii ‘Monstrose’) is that they will begin to grow at a faster rate once planted in the ground.  
 
In fact, smaller plants have an easier time becoming established then larger ones.
 
Many columnar types of cacti grow faster in the landscape then in the wild due to the presence of water – that includes saguaro cacti as well.
 
 
Like agave, you can start some species of columnar cacti from cuttings.
 
I planted this Mexican Fence Post cactus in my garden 11 years ago.  It started out as a 2 foot cutting given to me by a client from their large cactus.
 
Look how much it has grown!
 
You may notice on the lower right side that there has been a section cut off.  Soon, I’ll show you how to take a cutting from an existing cactus to create a new one!
 
 
3. Have a plan in place for planting your new cactus/succulent.
 
If you hadn’t noticed, many succulents are prickly.   So, it is a good idea to plan on how you are going to plant it.  Decide whether you can do it yourself or if you will need to hire someone to plant it for you.
 
For small cacti, you can use a towel to help you plant them without getting pricked.  See how here.
 
For larger cacti, you can use pieces of carpet or rubber straps.  But when in doubt about whether you can plant it yourself, hire an expert.
 
 
*As a golf course horticulturist, I used to transplant Teddy Bear Cholla (Opuntia bigelovii) from areas that were to be built upon.  I would use rubber straps to carry the cholla and regular kitchen tongs to pick up the pieces that dropped off.  I would then plant them elsewhere.
 
 
4. Keep an eye out for discounted plants.
 
Often, not all plants will meet the high standards of the nursery.  Sometimes, this can be mostly cosmetic damage, but occasionally you will see a succulent that has not been watered correctly or placed in too much or too little sun.
 
This can be a great way to save money and provide a little TLC to new succulents.  Research online how to care for that particular plant and soon you will have a healthy succulent growing in your garden that cost you a lot less.
 
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I hope that these tips will be helpful to you the next time you are shopping for succulents.

Now, you may think that I am talking about soft, cuddly puppies finding a new home.  But, I am actually talking about my agave pups.  The word ‘pups’ refers to the small agave offsets that sometimes form from the adult agave.

 Agave americana surrounded by her ‘pups’.

Some agave species produce quite a few pups, while other species rarely do.  I do try to stay from agave species like Agave americana because they produce so many pups that it becomes quite a maintenance chore to constantly remove them all.  But that being said, I have many friends and clients who just love this particular agave.

Well, the day finally came in my garden for my agave pups to move away from their childhood home.
Can you see them?  There are 4 in the picture above.  Three are quite small still, but more then ready to leave their mother, my Agave parryi.  I am actually quite excited to be getting pups from this agave because in my experience, they do not produce many pups.  It may be that this one has because it does receive overspray from my lawn sprinklers.
Okay, this may seem obvious, but you would be amazed at how many people just start digging in the middle of their gravel (granite) without clearing it away first.  Believe me…you want to clear it away first or else you will be left with a mixture of rock and soil mixed together.
 
Aren’t they cute in a prickly sort of way?  They really are quite tiny.
I carefully removed the soil around the pups, leading to the mother plant because the pups are still attached to her by a thick, fleshy root.  You can see that the pups are beginning to form their own roots, branching out to the side.
Just cut the root connecting the pup to the adult agave….that’s it.  It is really very easy.
Now, this same adult agave also has another pup, which has grown much closer to home then these tiny pups.
 
This one did not want to leave home, even though it was quite grown up.  When the pups are growing right up alongside the adult plant, just insert a shovel and push down firmly, cutting the connecting root.  **Sometimes you have to be a bit forceful in getting some pups to leave home  😉
I was able to harvest 5 pups.  I was so happy and had fun selecting where I wanted to put them in my garden.
Before you plant them, you need to put them in a dry, shady spot for 4 – 7 days so that the cuts have a chance to dry first.  This helps to prevent rot when they are planted.  Don’t worry about them surviving without water for a few days….they have plenty stored inside – they are succulents after all.
Once you have planted them, they will need supplemental water to help them establish and grow roots.  Agave do best when given supplemental water, even when mature.  Most are connected to my drip irrigation system.  The others receive overspray from my sprinklers, which is enough for them.
If you haven’t noticed this before, I am not a perfect gardener and am likely to tell people, “Do as I say, not as I do”.  But, I do not profess to be a perfectionist and so I will show you one of my larger agave, whose pups should have left home long ago…
smooth-edge-agave-pups
This is my Smooth Leaf Agave (Agave desmettiana).  I love this type of agave.  It is medium size, and the sides of the leaves do not have thorns.  The thorns on the tips can easily be cut off if desired for a more pedestrian friendly agave.
As you can see from the photo above, the pups are quite large and should have been kicked out long ago.  So, I brought in the muscle (my husband) to help get them out.
Because the pups were growing close to the parent plant, a shovel had to be used to separate them.
 
Agave desmettiana is known for producing offsets (pups), but in my experience, there are not too many.
Actually, the adult agave below was grown from a pup.
A proud parent and her 8 offspring.  I planted a few and gave some to my mother, Pastor Farmer, of Double S Farms.
There were times when I worked on golf courses that my budget was tight, so I would ask residents to bring their agave pups to me so that we could use them in landscape areas around the courses.  The residents were very generous and after a while, we had more then we knew what to do with.  So, if you have some agave pups, plant one in a pretty container and give to a friend or donate them to your city, church or other organization.
**My son continues to do better each day.  We did have a little bit of a setback on Saturday, but yesterday and today, he is feeling much better.  Thank you again for your support and prayers!

What comes to mind when you think of cactus?  

Perhaps the first thing you think of is the spines. If you have ever been unfortunate enough to have been pricked by a cactus, you’ll likely never forget that most of them have needles.  
*Did I ever tell you about the time I worked on golf course landscape and backed into a teddy bear cholla and got an entire piece lodged in the back of my leg?
 
Besides being painful to those who get too near to cacti, did you know that there are important reasons that cacti have spines?

Golden barrel cactuses (Echinocactus grusonii)

First, let’s look at the spines of cactus for what they are – the main part of cactus often functions as a modified stem, and its needles are the leaves.
 
The most obvious function of cactus spines is to protect the cacti from animals and people. There are, however, a few animals who aren’t deterred by the sharp spines of cacti such as javelina, tortoises and pack rats.

Saguaro cactus (Carnegiea gigantea) spines

 
Suprise, the primary function of the spines are to actually shade the cactus.
 
Although just one small spine would hardly provide shade, thousands of them can provide enough.
 

Why is sun protection needed for the surface of cacti? The shade from the spines let the cactus lose water through the atmosphere. This helps keep the cactus temperature relatively low.

Black-spine prickly pear (Opuntia macrocentra)

 Another function that the spines serve is that they help certain species of cacti such as cholla to root and spread.

Teddy bear cholla (Opuntia bigelovii)

Spines of the Cholla are specialized to detach and attach onto anything that comes to close. There are tiny barbs at the tips which grab on to anything that gets too close. It almost appears as if they ‘jump’ off of the main cactus as they latch on the unlucky recipient.

Segments of the Cholla are usually moved and then fall off and grow in better conditions. If you have ever seen cholla growing in large groups, this is why. 
**If like me, you are ever unlucky enough to find a piece of cholla embedded in your clothes or worse, your skin – you can use a comb to help pull out the barbs.  When hiking in the desert, it is easy to get them stuck on your shoes.  I usually grab a rock and use it to push off the Cholla segment.  When all else fails, a good pair of needle-nose pliers works.
 

Two young saguaro cactuses are emerging from the shelter of a creosote shrub.

Hopefully, you have a new appreciation for cacti and their spines.  But, it’s still important to be careful because it hurts when you get pricked!
Young saguaro cactus were peeking out from its bursage nurse plant.

As you walk through the desert, there are many opportunities to view some of the striking cacti and their unique shapes.  What is not initially apparent, are the many examples of plants helping young cacti survive.  However, if you look closely, it is all around you – desert shrubs and trees sheltering growing cacti from the harsh desert climate. 

Young barrel cactus underneath a bursage nurse plant
Despite their tough, prickly appearance, cactus are quite vulnerable.  Of the thousands of seeds that are released by each cactus, only a tiny fraction grow into new cactus plants.  Most would not survive if it were not for “nurse plants.”   These plants provide much-needed protection from the sun, cold temperatures and predators (including humans).  Nurse plants also provide much needed additional moisture for the new cacti.

Mammillaria microcarpa 

It is easy to walk by and not even notice the presence of the small cacti growing underneath nurse plants.  Most of the year, the fishhook cactus (Mammillaria microcarpa), pictured above, are almost impossible to see.  It is only in the spring when they are blooming that you can spot them.

Hedgehog cactus outgrowing it’s bursage nurse plant.

For the smaller cacti species, bursage (Ambrosia deltoidea) most often serves as the nurse plant.  It also often serves as the first nurse plant for saguaro cacti.

 
Two young saguaro cacti outgrowing their creosote and bursage nurse plants
 
Creosote (Larrea tridentata), palo verde, mesquite or ironwood trees often serve as the nurse plants for larger species of cacti.  As it grows larger, it requires more water and nutrients from the soil, which leaves little for the nurse plant.  So frequently, the nurse plant will decline and die as you can see from the photo above.

Young buckhorn cholla emerging from its bursage nurse plant.    

So next time you have the opportunity to take a walk in the desert, look around….you will most likely see examples of this unique relationship of plants helping young cactus survive.


Do you like prickly cactus?  

I have a few favorites, one being santa-rita prickly pear (Opuntia violaceae var. santa rita). The color contrast of their blue-grey pads and the shades of purple are so striking in the landscape.  

This cactus makes a beautiful accent plant for the landscape. Both the pads and fruit are edible, (but you might want to remove the spines first ;-). Cold temperature and drought intensify the purple color.

Santa-rita prickly pear is native to the Southwest regions of North America. They can grow as large as 6 ft. X 6 ft., but can be pruned to maintain a smaller size.  Pruning is done carefully, by making pruning cuts at the junction where the pads connect.


Lovely yellow flowers appear in spring followed by red fruit in the summer months.  Javelina, rabbits and pack rats will sometimes eat the pads. Pack rats use the pads to make their homes.

The pads of the prickly pear are covered with clusters of 2″ spines as well as tiny spines known as glochids. Glochids are incredibly irritating to the skin and detach from the pad very easily. Their tips have a small barb, which makes them difficult to remove from your skin.  If you need to handle them, use a few layers of newspaper or a piece of carpet. Do not make the mistake of touching the pads with gloves because the glochids will attach to your gloves and render them useless, (I ruined a perfectly good pair this way). 
 
 **There are different ways to remove these small spines, including applying Elmer’s glue (letting it dry and then pulling them off), but many people have reported greater success using duct tape. 

 

 
USES: In addition to serving as an accent plant in the landscape, this prickly pear species can also be used as a screen. Some may be surprised to learn that they also make excellent container plants, just make sure they are not near any foot traffic areas. They do well in full sun or light shade in well-drained soil.
 
MAINTENANCE: Prickly pear is very low-maintenance plants. I always use tongs to pick up the pads that I have pruned, or you can use newspaper.  
 
Although they are incredibly drought-tolerant, watering once a month during the hot summer months, in the absence of rain, will be appreciated and will improve the appearance of your prickly pear. Shriveled pads indicate acute drought-stress.
 
 

Many people believe that the appearance of white, cotton-like areas on the pads is a sign of a fungal infection. However, it is caused by a small insect that secretes the white cottony mass, called cochineal scale.  Control is straightforward – simply spray off it with a strong jet of water from the hose – that’s it!

 
PROPAGATION: Prickly pear can be planted from seed, but there is a much easier way. Just cut off a pad that is at least 6 inches tall. Put the pad upright, in a shady, dry place for at least about two weeks. This allows a callus to form at the bottom.  
 
Plant with the cut end down, do not water for the first month because the bottom is susceptible to fungal infections. After the first month, water every 2 – 3 weeks until established.  If planted in the summer, provide shade until established (about three months). *I generally do not recommend planting in the winter but encourage waiting until spring when the soil warms up. 
 
If you have a large prickly pear, you can prune it, or you can start over by taking it out and cutting off some of the pads and plant them in the same place. Many of my clients have done this and been happy with the results.
 
INTERESTING HISTORICAL FACT: The Aztecs would cultivate prickly pear cactus infected with cochineal scale because the insects secrete a dark red dye with crushed. This was used to dye cloth. The Spanish exported this dye from Mexico back to Europe where it was used to dye royal garments and British military uniforms. The dye was highly valued by the Spanish, next to gold and silver. It takes 70,000 insects to produce 1 pound of dye.
 
*This is but one of many beautiful prickly pear species available to the home gardener.   Do you have a favorite species of prickly pear cactus?
 
 There are some signs that summer is beginning to fade and that fall is around the corner.  The stress that the high temperatures of summer bring has caused many plants to slow down their growth.  
 
However, the slightly lower temperatures in September bring on a flush of new growth for many trees, shrubs, and succulents in the garden.  I enjoy being out in my garden this time of year and seeing many of my plants rejuvenated.
 

With the somewhat cooler temperatures, I am now seeing many gardeners venturing outside and taking stock of the condition of their landscape.  Fall is a busy time in the desert garden because it is the ideal time to install many types of plants, which will be discussed in a separate post in early October.

  
SHRUBS: I just finished lightly pruning my ‘Rio Bravo’ sage (Leucophyllum langmaniae).  Summer flowering shrubs that are cold-hardy look their best when lightly pruned at this time to help reign in rangy, sprawling growth. This should be only done with hand pruners only.  Do not use a hedge trimmer and shear your shrubs.  They should have a pleasing natural shape when you are finished.  Do not prune back frost-sensitive plants at this time.
 
 ANNUALS:  Although the local nurseries are abundant with winter annuals, I don’t recommend planting them now.  The temperatures are still quite hot, and there is a good chance that they will not make it.  
 

In the past when mid-September came, I would load up the truck with 100+ flats of annuals to plant around the community where I worked as the horticulturist.   I would then spent the next four weeks making repeated trips to the nursery to replace dead plants that just could not handle the heat of early fall.  From then on I would wait until October to change out summer annuals and replace with winter annuals.  As a result, we suffered very little plant loss.

TREES:  Mesquite and Palo Verde trees that are overgrown can be lightly easily pruned back.  Resist the temptation to heavily prune at this time.  January and February is the time for heavy pruning to occur for these trees.
 
SUCCULENTS:  Cacti, agaves and other succulent plants do best when planted when soil temperatures are warm, which makes September a great time to install them before cooler temperatures arrive.   Prickly Pear cactus can be pruned back this month if needed.  Problems with agave may show up this time of year. 
 
If your agave suddenly collapses, there is a good chance that they have gotten an infection with agave snout weevil.  There is no cure and the agave should be removed, it will be smelly due to the decay the weevil causes – and not just a little stinky.
 
One of my (least) favorite memories happened years ago when I worked as a horticulturist on a golf course.  One year, we had to remove countless agaves throughout the landscapes due to a large infestation – the smell was awful.  If this happens to your agave, do not plant another agave in the area – use another type of plant instead.
 
ROSES:  Roses should be lightly pruned and fertilized this month (see earlier post for details).
 

CITRUS:  Make sure to fertilize your citrus trees if you have not already done so (see earlier post for details).

 
NEXT MONTH – get ready for planting and wildflower garden preparation!
 

In the past, people have asked me how long does a saguaro cactus arm take to grow back. The commonly held belief is that it takes 100 years before they will develop an arm.

However, as with much plant information, this answer is not always correct, it actually takes less time for a saguaro cactus to grow its arm back in a landscape setting than it’s native habitat.  

The most critical factor in determining the timing of when a saguaro will start to grow an arm is the availability of water. Put simply, the more water a saguaro receives, the more quickly it grows. In a landscape setting where irrigation is present, a saguaro will grow much more rapidly then they do in their natural desert habitat. Saguaro cacti that grow in southern Arizona (near Tucson) grow more quickly than those in the western areas of the Sonoran desert because there is more rainfall in southern Arizona. 

A saguaro growing in its native habitat can take 50 – 100 years to grow arms. In a landscape setting, arms often appear much earlier.

The saguaro cactus is one of the most iconic plants of Arizona, (Carnegiea gigantea), it is perhaps the most recognizable trademark of the Sonoran desert with their tall arms reaching toward the sky.

Although, saguaros are only in some regions of the Sonoran desert. The vast majority are found in Arizona and Mexico. They are often found growing on the south side of the mountains due to the warmer air temperatures.
Another iconic Sonoran desert plant is the ocotillo (Fouquieria splendens) with its leaf covered canes topped with brightly colored flowers. Sometimes, people, mistake ocotillo as a type of cactus, but they’re actually a type of shrub.

Ocotillo produces beautiful vermillion blooms that attract hummingbirds and their canes leaf out occasionally in response to humidity and rain.
Agave macroacantha with ‘Firesticks’
 Succulents are some of my favorite types of plants. I especially like the smaller agave species such as Agave parryi, Agave victoria-reginae, and Agave bovicornuta to name a few.

Let’s talk a little about how to care for cacti and succulents. 

Silver Spurge (Gopher Plant)

Agave, cactus, yuccas, as well as other succulent plants, can continue to be planted during this month. Warm soil temperatures are necessary for succulents to grow and they do best when planted during the warm season.

‘Baby Rita’

Contrary to popular opinion, newly planted succulent plants need to be watered in order to become established and grow a healthy root system.

Established cacti appreciate some supplemental water during the summer months, (especially this summer with our non-existent monsoon). I typically water large cacti with a garden hose about once a month in the summer unless we have had a lot of rain.

Lophocereus schottii ‘Monstrose’

Some cacti and agave plants may show signs of yellowing in the summer. This is usually due to high temperatures. Be sure to give them some supplemental water if you notice the yellowing. Usually, the yellow color disappears once temperatures cool down in the fall.