Tag Archive for: Trees

Embracing Vibrant Fall Foliage in Arid Climates

Before you lament a fall season devoid of colorful fall foliage in the arid West and Southwest regions of the U.S., here are some favorite water-wise shrubs and trees that will add glorious color in varying shades of orange, red, and burgundy to your arid autumn landscape.

Fall Foliage we enjoyed on a trip to Williamsburg, VA several years ago.

we enjoyed on a trip to Williamsburg, VA several years ago.

Have you ever traveled somewhere else to find colorful fall foliage? What if you could have fall color in your own landscape?

A Splash of Fall Foliage Color in the Arid Desert

Like most water-wise plants, the following do best in well-drained soil. The watering guidelines given are approximate and may need to be adjusted in response to variables such as sun exposure, soil, and climate. In general, drought-tolerant plants do best when the soil is watered deeply and then allowed to dry out before the next watering. Plant in fall or wait until spring, and enjoy fall color for years to come.

Pink Muhly (Muhlenbergia capillaris)

Pink Muhly Grass (Muhlenbergia capillaris)

Autumn Pink

In spring and summer, this ornamental grass provides an attractive backdrop with its graceful green foliage. As temperatures begin to fall and days begin to shorten, burgundy-pink plumes softly wave above the green blades, and pink muhly grass takes center stage in the garden. Its color slowly fades to a lovely wheat color in winter. Plant it in groups of three, five, or seven for the greatest effect.

Growing Conditions

Where it will grow: Hardy to 0 degrees Fahrenheit, or minus 18 degrees Celsius (USDA zones 7 to 9; find your zone)

Water requirement: Low to moderate; can survive on little water, but flowering is improved with regular summer irrigation. Water every 10 to 14 days in summer, every two weeks in spring through fall, and monthly in winter for the best flowering.

Light requirement: Full, reflected sun to filtered shade

Mature size: 3 feet tall and wide

Planting notes: Plant in well-drained soil in full sun or filtered shade; cut back to the ground in late winter; apply a slow-release fertilizer in spring.

‘Sticks on Fire’ Milk Bush (Euphorbia tirucalli ‘Sticks on Fire’)

Unexpected Bursts of Orange

Orange splashes of color come from an unexpected source with this drought-tolerant succulent. ‘Sticks on Fire’ differs from the green-colored parent plant in that it is smaller and new growth has a bright orange color. The color fades to yellow and then green in summer only to turn orange again when temperatures cool. In cooler climates it can be grown in a container and brought indoors when temperatures dip below freezing. Milk bush can easily be propagated from cuttings. Be sure to wear gloves when handling this plant, as its milky sap can irritate skin and eyes.

Growing Conditions

Where it will grow: Hardy to 30 degrees Fahrenheit, or minus 1 degree Celsius (zones 9 to 11)

Water requirement: Low; water every three weeks spring through fall and monthly in winter. In the low desert, water twice a month spring through fall.

Light requirement: Full sun to filtered shade (full sun is needed for it to develop the orange color)

Mature size: 4 to 8 feet tall and 3 to 5 feet wide

Planting notes: Plant in well-drained soil in full sun.

Chinese Pistache (Pistacia chinensis)

A Burst of Fall Foliage

Chinese pistache is for those who are looking for a tree that produces colorful fall foliage and will thrive in dry, arid climates. It is widely grown throughout the Northwest and the southern half of the United States, and is a go-to tree for reliable autumn color in the Southwest. In fall, bright green leaves give way to shades of yellow followed by orange and red, providing much-desired fall color for the drought-tolerant garden. Female trees produce berries that attract birds. This tree isn’t fussy about soil, as long as it’s well-drained, but it does need room to grow to its full size.

Growing Conditions

Where it will grow: Hardy to minus 10 degrees Fahrenheit, or minus 23 degrees Celsius (zones 6 to 9)

Water requirement: Low to moderate; water to 3 feet every 10 to 14 days in summer, every three weeks in spring through fall and monthly in winter

Light requirement: Full, reflected sun to filtered shade

Mature size: 30 to 60 feet tall and 30 to 40 feet wide

Planting notes: Plant in well-drained soil in full sun or filtered shade; prune in winter to shape.

flowering shrub

Firebush (Hamelia patens)

N

A Blaze of Color and Fall Foliage

The allure of firebush goes beyond its stunning orange-red spring and summer blooms, which are a magnet for hummingbirds. It saves its grand finale for fall when its lush foliage transforms into a vibrant shade of red, creating a fiery spectacle. In tropical climates, this heat-loving shrub can grow into a small tree, while in drought-tolerant landscapes, it remains a manageable and colorful shrub. Although it dies back when temperatures dip into the 20s, it resurfaces in spring. In zones 7 and below, it can be grown as an annual.

Growing Conditions

Where it will grow: Hardy to 10 degrees Fahrenheit (zones 7 to 11)

Water requirement: Moderate; water 18 inches to 2 feet deep weekly in summer, every 10 to 14 days in spring through fall, and every three weeks in winter

Light requirement: Full and reflected sun to filtered shade (full sun is best for flowering)

Mature size: 4 to 5 feet tall and wide

Planting notes: Plant in well-drained soil; prune back in spring, after the danger of frost has passed.

‘Krauter Vesuvius’ Cherry Plum (Prunus cerasifera ‘Krauter Vesuvius’)

A Regal Purple Masterpiece

This plum tree species is renowned for its regal burgundy-purple foliage that graces the landscape from spring through fall. Despite being a plum tree, its fruits are typically small or nonexistent, as its true value lies in its captivating foliage. Pale pink springtime blossoms are soon followed by the emergence of dark-colored leaves. While several cherry plum varieties exist, ‘Krauter Vesuvius’ stands out as the most drought-tolerant, making it ideal for enduring hot, dry summers.

Growing Conditions

Where it will grow: Hardy to minus 20 degrees Fahrenheit (zones 5 to 9)

Water requirement: Moderate; water 2 to 3 feet every 10 to 14 days in summer, every two to three weeks in spring and fall, and monthly in winter. In the low desert, water weekly in summer and every 10 to 12 days in spring and fall.

Light requirement: Full sun to filtered shade (full sun is needed for maximum purple color)

Mature size: 15 to 20 feet tall and wide; smaller cultivars are available

Planting notes: Plant in well-drained soil; prune during winter dormancy.

Heavenly Bamboo (Nandina domestica)

A Bamboo-Like Marvel with Radiant Red Fall Foliage

Heavenly bamboo, often likened to true bamboo due to its fine-textured leaves and upright stems, unveils a delightful transformation in fall and winter. The new growth takes on a charming burgundy tint before transitioning to a bright spring and summer green. As cooler temperatures grace the landscape, the foliage transitions into enchanting shades of red. Additionally, small flowers give way to clusters of red berries in autumn. While moderately drought-tolerant, it thrives in arid regions, maintaining its vigorous growth in controlled environments.

Caution: Heavenly bamboo can become invasive in regions with abundant rainfall, especially in the eastern U.S., and all parts of this shrub are toxic.

Growing Conditions

Where it will grow: Hardy to minus 10 degrees Fahrenheit (zones 6 to 9)

Water requirement: Low to moderate; water 18 inches to 2 feet twice a month in summer, every three weeks in spring and fall, and monthly in winter. In the low desert, water weekly in summer and twice a month in spring and fall.

Light requirement: Full sun to filtered shade (prefers filtered to full shade in the low desert)

Mature size: 4 to 6 feet tall and 3 feet wide; smaller cultivars are available

Planting notes: Plant in well-drained soil; selectively prune older branches at the base in late winter or early spring.

Do you have a favorite plant that gives you fall color?

 

 

Drive By Landscapes: Winter Beauty in the Southwest Garden

When you visit a nursery, do you wonder which plants are drought tolerant as opposed to those who will wilt if not given enough water?

There are a few different traits that many drought-tolerant plants share.  For example, did you know that small leaves and gray foliage can be signs that a plant may be drought-tolerant?  

I recently shared several traits to look for when shopping for drought-tolerant plants for Houzz.com

I hope this article will help you to create a beautiful, drought-tolerant garden!

How to Spot a Drought-Tolerant Plant

Citrus Trees Need Sunscreen

Last week, I was visiting one of my favorite clients when I noticed that one of her citrus trees was showing signs of sunburn, which led to me explaining to her that even citrus trees need sunscreen to prevent sunburn in many cases.

Citrus Trees Need Sunscreen or they can become sunburnt like this tree

Recognizing Sunburn Symptoms

You can see the lighter-colored bark and some cracks as well along the branch. It turns out that citrus trees are very susceptible to sunburn.

Why Sunburned Citrus Trees Are a Concern

So, why is a sunburned citrus tree something to be worried about?

Well, when a tree becomes sunburned, it often forms cracks in the bark and within these cracks, damaging insects or fungus can find a nice home.  Frost damage can also cause cracks in the bark.

In recent years, I have had to deliver bad news to people whose citrus trees became infected with sooty canker, which is a fungal disease that affects the branches and trunks, which takes root underneath the cracked, flaky bark.

Citrus Trees Need Sunscreen and often develop sooty canker without proper protection

Managing and Protecting Your Citrus Trees

Several times, I have had to tell homeowners that their much-loved citrus tree was badly infected with sooty canker and had to be removed.  You can read more about the signs and treatment of sooty canker, here. Citrus can have many types of concerns. Sunburn is a concern as well, but you can protect your trees.

Preventing Sunburn; Citrus Trees Need Sunscreen

Thankfully, there are things we can do to reduce or eliminate the chance of sunburn to our citrus trees. Citrus trees need sunscreen.

Citrus trees with full rounded growth

1. Encourage Lower Branch Growth

Allow citrus trees to grow their lower branches. They will help to shade the trunk.  A bonus for citrus trees grown this way is that the most fruit is produced on the lower branches that also tastes sweeter.

Citrus Trees Need Sunscreen painted base

2. Use Protective Measures

Protect exposed trunks and branches by using citrus paint (available at your local nursery) or by simply mixing white latex paint water so that the resulting mixture is 1/2 paint and 1/2 water. You can also purchase tree wraps made from burlap, which can also help to protect them. Avoid using oil-based paint.

However, if you allow the lower branches of your citrus tree to grow and the trunk is shaded, than you don’t have to paint them. 

over pruned citrus trees

3. Prune Wisely

Don’t over-prune your citrus trees.  The photo above, is an EXTREME example of what not to do.

Citrus trees should be pruned in March, and concentrated on removing dead, diseased or crossing branches. Avoid pruning more then 20% of its foliage in any given year. Remember, that the leaves make food for the tree, which will in turn, produce delicious fruit. If pruning leaves you with exposed branches, then coat them with citrus paint.

**See how to protect citrus from the damaging effects of a heat wave – here.

Even Citrus Trees Need Sunscreen to Prevent Sunburn

A little note about sun exposure: I always wear sunscreen whenever I venture outdoors.  Years spent in California at the beach as a teenager, trying to tan my fair skin did not work.  Now, I try very hard to protect my skin from the desert sun.  I do however, often forget to wear my hat as it does mess up my hair 😉

It may be awfully hot outside, but my garden is awash in brightly colored flowers from my single bougainvillea, Arizona yellow bells and ‘Rio Bravo’ sage, which shrug off the summer heat.

Summer Edible Garden

Last year, we decided to create an edible garden along the side of our house.

This was a large underused area that we look out at from our kitchen, family room and bedrooms.

To get it ready for planting, we had our ghost gum eucalyptus tree removed.  It was a beautiful tree, but was quickly outgrowing this area with its overhanging limbs.

The next step involved pulling out some of the flowering shrubs along the back wall and along the side of the house.  We kept the flowering shrubs along the side wall, because they add beauty and help to break up the bare expanse of the wall.

This is what the side garden looks like today…

Summer Edible Garden

The centerpiece of the edible garden is the vegetable garden.  Right now, it is filled with corn, zucchini, tomatoes, cucumbers and sunflowers.

In front, is my colorful container filled with a variety of herbs including basil, parsley, sage and thyme.  I bought an inexpensive plastic container and spray painted it a bright blue.  The container is connected to the drip system of the vegetable garden.

Arizona sweet orange tree

In the foreground (not pictured) is our new Arizona sweet orange tree.  We planted it last year and are excited to have three oranges growing on it.

You may be thinking that three oranges is not much to be excited about, but the first couple of years after a citrus tree is planted – you are lucky to get any fruit at all.

Newly planted citrus trees shouldn’t be fertilized during the first year, because you want them to focus on root growth, not upper growth when there is not a substantial root system for them to rely on.  Since it has been a year since we have planted it, we will fertilize this year.  

new peach tree

In front of the vegetable garden are a pair of new peach trees.

I love peaches and have enjoyed the fruit from my mother’s peach trees for years.  I finally decided that I wanted to grow my own.

We got 18 peaches this year, which is a lot considering that we planted them in January.

Notice the green plant at the base of the peach tree?  It is a gourd plant that will quickly grow and cover the ground.  This will serve as a ‘living mulch’ and help to prevent weeds and shade the roots of my peach trees.

sunflower

Inside the vegetable garden, sunflower seeds are beginning to form.  It is so fun to see the birds hanging upside down trying to get to the seeds.

You can allow the birds to eat the seeds or if you want to save them for yourself, simply tie a paper bag around the flower to keep the birds away.

I’ll probably save some flowers for ourselves and let the birds enjoy the seeds of a couple of unprotected sunflowers.

zucchini plant

A large zucchini plant is growing in the background and as anyone who has grown zucchini will tell you, it is prolific.

The slightly wilting plant in the foreground is a pumpkin plant.  If you want a pumpkin for fall, then June is when you want to plant them.

It is normal for the leaves to wilt slightly during the heat of the day.  They will return to normal later in the day.

zucchini plant

Zucchini can hide underneath the large leaves of the zucchini plant.  I’m going to use this one to make my chocolate chip zucchini bread.  It’s delicious and your kids will never know there is zucchini in it 😉

I found the recipe on Pinterest and have already made it once.  My family keeps bugging me to make more.  Here is the link to the recipe, if you are interested – Chocolate Zucchini Bread

Summer Edible Garden

My tomatoes are flourishing in the natural shade provided by my sunflowers.

cherry tomato plants

One of my cherry tomato plants has even decided to expand a bit outside of the garden.

two apple trees

Behind the vegetable garden are my two apple trees, planted this January.  One is a Anna apple tree and the other is a Dorsett Golden. These apple trees do well in the desert and although they will produce apples if planted alone – they will produce more apples because they will cross pollinate each other.

It will take a few years for any apples to appear, but the blossoms in spring are just lovely.

Summer Edible Garden

Behind the apple trees are six blackberry bushes.  This year, we enjoyed the berries so much and are hoping for even more next year as they grow larger.

Blackberries won’t produce the first year after planting because the berries appear on 1-year odd canes.

Did you know that there are now thornless varieties of blackberries available?  I have one….I only wish that the other five were thornless 😉

Well, that is what I have growing in my side edible garden.

Tomorrow, I’ll share what is growing in my original vegetable garden.

What do you have growing in your garden right now?

A Summer Edible Garden: Part 2

Last Saturday was a day that we had long prepared for.

My husband and I had spent countless hours sitting alongside my youngest daughter, Gracie, helping her practice for her piano recital.

She was nervous, but looked so cute in her new dress and shoes.  

 my youngest daughter, Gracie

The recital was held at the Mesa Arts Center and Gracie was playing along with her entire class.

As we were waiting for our turn to go inside, I saw something rather unusual in the distance.

The Mesquite trees looked rather colorful.  So, I walked a bit closer….    

 knit scarves

No, my eyes weren’t deceiving me.  These trees had knit scarves covering parts of their trunks.

Knit Scarves for Trees

Now, I like to knit scarves for loved ones – but this was the first time that I had ever seen them on trees.

Knit Scarves for Trees

Even the Pine trees had colorful, knit scarves.

I couldn’t imagine why anyone would spend so much time knitting scarves and then ‘sewing’ them around tree trunks.

The trees don’t need protection from the cold.

I needed some answers, because I was pretty sure that they didn’t cover this in my Trees class in college or when I took my Certified Arborist exam.

I spotted a security guard walking nearby and asked him why the trees had knit scarves.  He explained that the trees were the focus of a group to beautify the urban landscape.

What they did is referred to as ‘Yarn Bombing‘, which is described as “The Art of Knit Graffiti.”

‘Yarn Bombing’ is occurring in urban areas throughout North America in an effort to add beauty to urban areas.

Well, I must admit that I thought the trees looked quite nice.

Knit Scarves for Trees

But, I think they might get a bit ‘warm’ as the temperatures begin to rise 😉

They will soon be taken down, so if you live nearby – stop by before the ‘knit graffiti’ is taken down.

****************************

While we were at the recital, we got our first phone call from my daughter, Rachele, who is away at basic training for the Navy.

It was so good to hear her voice!

She is homesick and is trying hard not to be discouraged.  She has finished one week of basic training and is learning how to do things “the Navy way”.

Rachele joined up with a division that had already been there a week before and needed a few more recruits.  So, she has less time to learn how to do things.

Learning how to make their beds and folding clothes a certain way is hard and they come around with a ruler and if you are 1 cm off, you get in trouble.

I can see why this would be hard for her, since most of her clothes never made it into her dresser at home 😉

It has been cold there (outside Chicago) and they have three different jackets and knit caps that they wear when they have to march from building to building (2 miles).

She was given good advice before she left by her then boss, who is a retired Army colonel.  He said to do your best to blend in and don’t volunteer for anything.  It just makes basic training that much harder.

So far so good, she said.  Her RTC doesn’t know her name, which is supposed to be good.

She has passed her swimming test along with many of her other physical tests – so that is good news.

The recruits aren’t allowed to talk to each other.  But, some try to talk to each other at night after lights are out.  However, some get caught and have to do extra exercise.

We are doubling up on our letters to keep her spirits up.

From what we hear, everything she is experiencing is normal, including the homesickness.  It is supposed to get better around week 4, once they start to get used things.

As for me, I was a weepy mess after I spoke to her.  I do miss her so much.  But, I believe that she will make a wonderful sailor 🙂  

landscape consults

What is wrong with the picture above?

A few days ago, I decided to start writing about some of the “landscape no-no’s” that I see when I am doing landscape consults.

From time to time, I will focus on a particular “landscape no-no” and its solution.

My hope is that it will help you to avoid or fix these problems.

My first “landscape no-no” post, featured the photo above.  Readers were invited to figure out what was wrong and leave a comment.

Quite a few of you left comments, correctly identifying the problem.

But, for those of you who aren’t sure what is wrong with the tree above – look closely at the drip emitter….

The problem is that the emitter is too close to the trunk of the tree.

Initially, when trees are first planted, it is a good place for the drip emitter to be.  The roots are primarily near the trunk.

However, as a tree grows, so do its roots.  The single emitter next to the trunk of a mature tree, isn’t doing it any good.

The roots grow outward and their ends are concentrated where the branches end. The reason for this is that when rain falls, the majority of it drips off the ends of branches – so that is where roots tend to grow out to.

So, if your tree and emitter(s) look like the photo above; how can you ‘fix’ it?

landscape consults

As your tree grows, you need to add more emitters, equally spaced around your tree.  They should be located where the tree canopy (branches) end. (I do recommend burying your drip line – it looks better 🙂

Below, is a photo of a large tree and I have drawn in recommended emitter placement…

landscape consults

You can see the emitters are widely spaced around the tree and are located where the tree canopy ends.  As your tree grows, you need to continue to move the emitters outward.

The Arizona Municipal Water Users Association has a great, free publication that guides homeowners through landscape watering, including recommended watering schedules….

landscape consults

The diagram above, from “Landscape Watering By the Numbers” shows recommended emitter placement along with how deeply trees should be watered.

It’s important to note that trees do not need to be watered as often as your other plants.  But, they do need to be watered more deeply – 3 feet.

(Here is a link for how often to water your trees and other plants if you live in the greater Phoenix metro area).

**If you don’t have a separate irrigation line for your trees, you can periodically deep water your tree by turning your hose onto a slow trickle and let it slowly soak into the soil.  Move the hose until the entire outer canopy of your tree has been watered.

So, do you have this “landscape no-no” in your garden?  Don’t worry – now you know how to fix it 🙂

**Stay tuned for our next “landscape no-no” soon!**

To receive your own copy of “Landscape Watering By the Numbers”

simply click the link above.  You can also view it online.  Note – this publication is written for residents of the greater Phoenix area, but the information is very helpful to anyone who lives in a hot and dry climate.

landscape consultation

Do you ever wonder if you are doing things right in your landscape?

If a plant or tree doesn’t look too well, do you wonder if it is something you are doing wrong?

When I am called to do a landscape consultation, my client usually has a primary concern.  But, part of my job is to also look at the landscape as a whole and point out other problems – hopefully before they affect the plant negatively.

So, I decided to start posting photos of problems I have spotted during consults in hopes that I can help you too.

Below, are two pictures of a very common landscape mistake that I see constantly.  Usually the homeowner/client has no idea that they are doing anything wrong.

Can you tell what is wrong?

landscape consultation

It isn’t always super obvious…

landscape consultation

 I’d love to hear what you think is wrong – just send me a comment, below.

I’ll post about this ‘landscape no-no’ and what problems it causes and how to correct it in my next post 🙂

Okay, I must begin this by admitting that I have no idea what to post about today….

Maybe I shouldn’t admit this to you, but there are times when I have nothing.  I think it may be because there is so much going on in my life. 

hot Southwest summer

– My three youngest kids start school on Monday (we have a modified year-round school calendar).  My daughter Ruthie, begins Jr. High and is understandably nervous.  We went shopping yesterday for some new clothes and shoes.

– We have guests arriving tomorrow from Kansas City who we will be entertaining for the weekend.  There is a very special story behind these people and my daughter Ruthie.  I can’t wait to share it with you later 🙂

– I just finished writing 4 gardening articles and have one more left to go.

– We are busy helping my in-laws each week with miscellaneous tasks around their home.  My father-in-law is continuing to suffer more debilitating effects from ALS.

However, with all of this going on, my garden is thriving.  I thought that I would share with you some summer things that you should do in your garden.  

It is from an article that I wrote earlier this month for a local community newsletter.  I hope you enjoy it 🙂

hot Southwest summer

Thankfully, there is not a lot of things to be done in the garden during the hot Southwest summer, but there are some tasks that are important this time of year.  

I recommend going out into your garden during the early morning hours to do these tasks, as I do, or at dusk, once the sun begins to set to avoid the extremely hot period of the day. So, put on your hat, sunscreen, gloves and sunglasses and let’s get started.

hot Southwest summer

Hot Southwest summer

Succulents: Cacti, agave, yucca and other succulent plants can suffer from both the extreme heat and sun of summer, especially on the side of the plant that points toward the southwest. Signs of heat damage include a yellowing of your succulents. If your succulents are not connected to your irrigation, they need to be watered to a depth of one to two feet. Larger succulents such as saguaro, ocotillo and yuccas need to be watered to three feet deep. Do this once this month and again in August. 

This can be easily done by simply placing your hose next to the plant and barely turning the water on so that the water trickles out slowly. Leave the water on for at least an hour and then check to see if you need to leave the water on for longer.

Shrubs: Make sure that your shrubs are receiving enough water. They should be watered to a depth of 2 feet each time you water. Avoid fertilizing this time of year since this creates more stress for your plants, which are struggling to handle the heat of summer. You can deadhead spent flowers from your shrubs to promote additional bloom, but avoid pruning away any foliage at this time of year. Spider mites can become a problem this time of year. Look for any tiny webs, which are a sign of these tiny mites. Controlling them is easy since they like to hide in the dust, so spray your plants every few days with water to help keep the mites from becoming established.

hot Southwest summer

Hot Southwest summer

Trees: Avoid planting any trees this month, except for palms. Mature, established trees require deep watering this time of year, especially if they are not connected to your irrigation system. This should be done once a month in summer, watering to a depth of 3 feet. Using a hose, allow water to slowly trickle out around the drip line of the tree (where the branches end, not against the trunk) which is where the roots are located. You may need to move the hose so that you water around the entire tree. You can skip one watering if you receive 1 inch of rainfall, which replaces a single irrigation. 

As the increased humidity, (25 – 33% humidity is considered high in the desert), makes it more uncomfortable for us to go outside, it helps to keep in mind that plants just love the extra moisture even if it is only in the air around them.

**I hope you find this helpful.  I wanted to also tell you about a fabulous sight that I saw on our vacation.  I blogged about it on my Birds & Blooms blog.  

Ficus nitida

Ficus Nitida simply the wrong plant, and usually in the wrong place.

I think this photo probably speaks for itself…..

But, I will add to it by saying that it is vital to realize that the little, spindly tree that you plant WILL GROW. Be sure to check the mature size of any tree, (or any plant for that matter), before you plant so you can be sure that there is ample room for growth.

By the way, the tree above is a Ficus nitida, which is a beautiful, dark green tree. But, it does grow enormous, as does its roots, making it unsuitable from most residential landscapes.