Each time I go on a landscape consult, it is an adventure.  I never know what to expect. Will there be serious problems with any of the trees and plants?  Or will my help be needed to re-design the landscape, adjust the irrigation schedule or help people learn how to maintain their plants?  Well, life is full of surprises. 

Of course, every time I go on a consult, I always bring my camera.  I am always looking for examples of beautiful plants and problems to photograph.  I then share many of them with you.

Yesterday, was a gorgeous spring day.  The high was 78 degrees and I actually had two consults scheduled, within two miles of each other.  My first client had just bought a new home and wanted help identifying her plants and how to take care of them.  She also had inherited some sick citrus trees and needed help in how to help them.

First the good things that I saw….

white flower

I was greeted by the front entry by this spectacular white flower.  Argentine Giant (Trichocereus candicans), is a cactus that is highly desired.  It produces flowers a few times during spring and summer months.  This particular cactus was absolutely covered in these large blossoms.

identifying plants

Nearby the Argentine Giant, was the smaller Claret Cup Cactus (Echinocereus triglochidiatus) awash in bright orange blooms.

identifying plants

An unusually shaped flowering Twin Flower Agave (Agave geminiflora) caught my eye.  Normally, they produce a single flowering stalk like the one on the left.  However, the one on the right had seven smaller stalks.  I love seeing examples of plants that are doing something out of the ordinary 🙂

Now for the bad….

identifying plants

This is one of the four sickly citrus trees that I was asked to see.  The diagnosis was relatively easy.  Lack of water and nutrient deficiency.  Both problems will be solved by enlarging the basin underneath the tree so that it extends out to where the branches end.  As the tree grows, so must the basin since a trees roots extend outwards where the branches extend.  A new watering schedule and making sure that the water penetrates to 3 ft. in depth should do much to help these trees.

Nutrient deficiencies are corrected by fertilizing citrus trees three times a year – in Feb/Mar, May and September, using either a synthetic or organic fertilizer specially formulated for citrus which contains not only nitrogen, but also micronutrients that are often deficient in our soils.  

More information on citrus care, irrigation and fertilization can be found here.

identifying plants

As I walked the landscape with the homeowner, we started looking at the trees that she had inherited with her new home.  I quickly noticed something very bad.  The previous homeowners had never removed the stake and cables from their tree when it was young.  

The tree ended up growing around the wire and there is no way to remove it now without seriously damaging the tree.  Usually, when wires are left on the tree, they gradually cut off the nutrients to the tree as the “veins” of the tree are located directly underneath the bark.  This usually results in the death of the tree.  However, this Mesquite tree appears to have survived and regrown it’s vascular (veins) system around the wire.  The tree is 11 years old and is the exception in terms of surviving this type of treatment.  

identifying plants

**If your trees are staked, PLEASE make sure to check your wires/cables to make sure that this does not happen to you.  Trees are not to be staked forever, only the first 1 – 2 years after planting.

identifying plants

Now the next bad thing I observed was not immediately obvious, but as I began to focus my gaze upwards to evaluate the trees, I saw a few clumps of mistletoe (Phoradendron californicum) growing in the tree.  Now, this is not the same kind of leafy mistletoe that is often seen at Christmas.  But it is a parasite that will, over time, cause a decline in the tree and stress the tree.  This makes the tree more susceptible to disease, insect infestations and other stresses. 

As an arborist, I have taken part in discussions regarding whether or not you should leave mistletoe in trees.  Mistletoe is part of the natural desert and can be seen growing in trees in the wild. Mistletoe itself will not kill a tree, but does stress the tree and leaves it vulnerable to disease, insects and environmental stresses that will kill the tree eventually.  

 In managed landscape areas I have always had mistletoe removed.  In my opinion, trees do not need any additional stress and the trees are part of a larger landscape design and aesthetics are important.  

I also recommend that homeowners also remove the mistletoe from their trees.  Not only will it help their tree, but will help keep the mistletoe from spreading to their neighbor’s trees.  Mistletoe is spread when birds eat the berries it produces and then they ‘poop’ them out on another tree’s branch and the seed germinates and starts to infect the branch it landed on.

identifying plants

Small clumps of mistletoe are not always obvious, but once you know what to look for, you will easily be able to spot it.  I recommend looking at your tree in the winter, when there are fewer leaves to hide the mistletoe.

There are two ways to remove mistletoe.  To completely get rid of it, you need to cut the branch that it occurs on at least 12″ below where the mistletoe begins.  In most cases, this will completely get rid of the mistletoe.  This works best with smaller branches.  However, if you have a very large branch that is infected, it may not be feasible to remove the branch.  In this case, you can prune the mistletoe off – just take your gloved hand and brush them off of the branch.  It is really that easy.  Doing this will not get rid of the mistletoe, but help to control it.  You will have to continue to do this periodically to keep the mistletoe from becoming larger and spreading.

identifying plants

Now on to my second client of the day.  Overall, is landscape was in good shape.  His citrus trees were healthy as were the rest of his plants.  But, the majority of his concerns were in regards to his irrigation system.  His mature Palo Brea tree (Parkinsonia praecox), pictured above, still had the irrigation emitters positioned by the trunk of the tree.  The same place that they had been place 8 years ago.  The problem is, the roots have now moved.

I explained to him that as a tree grows, so do the roots.  They grow outwards, toward the edge of where the branches extend.  And so as the tree grows, the emitters need to be moved and places around the tree where the branches end.  For this tree, three 2 (gph) emitters evenly spaced around the tree will work just fine.

Well, I had a very fulfilling day working with some very nice people.  I just love help people learn how to care for their trees and plants and spend time outdoors and admiring the beauty in people’s gardens.

As I was leaving, I saw something very ugly….

 Mesquite tree

This homeowner had ‘topped’ his Mesquite tree.  Now, I am not sure why they had this done.  I could tell that from looking at the branches, that it was not the first time it had been ‘topped’.

Now any arborist will tell you that ‘topping’ is bad and there are a number of reasons why.  I will address it further in another post, but will leave you with these few reasons NOT to top your trees:

-It causes the tree to grow more quickly to replace the leaves lost, therefore increasing the amount of pruning needed.

-The new branches will not be firmly attached and will be more likely to break.

-Topping stresses the tree, making it susceptible to disease, insects and environmental stresses.

-If those reasons are not enough, then maybe this one will be….IT IS UGLY.

*For more information on the damage ‘topping’ trees does, you can visit The International Society of Arboriculture.

Thank you for hanging in there with me…I realize this was a long post, but there was so much to ‘talk’ about from my visits yesterday.  I hope you enjoyed the beauty of the flowers and that maybe I have helped people avoid some of the problems that I have highlighted.

“Scary” Pruning Practices and the Unfortunate Results

During a visit to a park, I came upon a beautiful little garden that rests on top of 2.2 million tons of trash.  This small succulent garden is but a very small part of the park which rests upon a recently closed landfill.

beautiful little garden

Newly planted cacti, aloe and agave.  Ocotillo stand in the background. In the background, you can see that the walls are made of wire encased stones.

This landfill was closed in 2005 and the new park has not officially opened.  However, that did not keep me and my husband from exploring.

beautiful little garden

A collection of Mammillaria backebergiana. Many of them were getting ready to flower.

beautiful little garden

 Close-up of the flowers beginning to open. I love how the flowers form a ring around this little cactus.

We hiked to the top of the park, (or should I say, the top of the trash heap), which is the second highest point in the city.  Once at the top, it is very easy to view the surrounding mountains (Superstition, San Tan, South Mountain, the McDowell’s and Four Peaks).

beautiful little garden

A collection of Green Strawberry Hedgehog (Echinocereus enneacanthus engelmannii) and young Aloe.

beautiful little garden

There is just something I love about a boulder with lots of character like this one.  They add so much texture to the garden and you don’t have to water or prune them.

The canal runs by the park and paths for both bikes and horses encircle the park.

beautiful little garden

Mammillaria macdougalii 

As you can see from the photo above, contrary to popular opinion, cacti and other succulents do best when watered initially until they become established.  By using drip-irrigation, it is very easy to just plug up the emitters later or put on an adjustable emitter.

*Note how the emitter is not placed up right next to this cactus – it is placed a little ways away to help keep the roots from rotting. 

young Agave

A young Agave desmettiana and the Mammillaria receive water from the drip-irrigation system. The plantings in the far background look very sparse, but will grow very  quickly. 

Mountain of Trash

 I love how recycled, broken concrete was used to build the walls of this garden.

I love that used recycled, broken concrete was utilized to make the walls of this succulent garden.  

A Garden Arises From a Mountain of Trash

The garden is covered with canvas shade panels which look like they can be easily removed once the cacti and other succulents become established.

*Many cacti and succulents do best when temporary shade is provided when they are moved and transplanted.

I had a wonderful time visiting, but all too soon it was time to leave….for the grocery store.

A Garden Arises From a Mountain of Trash

But, I will be back soon….

*Please click the following link for more information about The Paseo Vista Recreational Area

spines of cactus

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?

spines of cactus

 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.

spines of cactus

 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.

spines of cactus

 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.

spines of cactus

 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.

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.

**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.

young saguaro cactuses

 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!

What Plant Where? Beautiful Plant Combinations

nurse plants

 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. 

nurse plants

 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.

nurse plants

 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.

nurse plants

 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

 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

 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.

Drought Tolerant and Beautiful: Globe Mallow

prickly cactus

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.

prickly cactus

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. 

prickly cactus

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.

prickly cactus

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!

prickly cactus

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?

summer is beginning

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.

summer is beginning

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.

summer is beginning

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.

summer is beginning

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.

summer is beginning

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. 

summer is beginning

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:  Roses should be lightly pruned and fertilized this month (see earlier post for details).

citrus trees

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!

Saguaro cactus

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.

 Desert Plants

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.

 Desert Plants

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.

Care of Cacti

 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. 

Care of Cacti

 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.

Care of Cacti

 ‘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.

Care of Cacti

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'

Care of Cacti, 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.

Pink Crown of Flowers

I just had to share this photo of my flowering Arizona fishhook cactus(Mammillaria grahamii) also known as (Mammillaria microcarpa).

While walking outside in the garden this morning, I caught a glimpse of pink off in the distance. As I went over to explore further, I noticed my little Arizona fishhook cactus in full bloom. I don’t have many cacti in my garden, but even if I did, this little one would probably still be my favorite. 

Fishhook Cactus

Pink crowns of flowers appear off and on throughout the summer months in response to rain much to the delight of native bees.

Fishhook Cactus

I found this little cactus growing alongside a large boulder in an area of desert that was getting ready to be graded for a new house. At the time my crew and I were digging up different types of cacti, like barrel cacti and teddy bear cholla, to relocate them around the site out of harm’s way. I received permission to keep this little one.

One of the things that I love about this little cactus is its flowers off and on during the summer months in response to rain or a small amount of water from my garden hose.

Fishhook Cactus

Look closely at the spines, you can see where it gets their common name with their fishhook shape.

Believe it or not, I can hold this cactus (carefully) without getting pricked.

During the rest of the year, this small cactus fades into the background and is hard to see.  You can find it growing underneath bursage shrubs throughout the desert.

Do you have a favorite flowering cactus in your garden?

New Perennial Discovery and a Baby