Asparagus Fern is my # 8 in the top Ten heat resistant plants

Introducing the dramatic Asparagus densiflorus.  Even when southern Arizona reaches temperatures above 100 degrees the asparagus fern thrives!  Our desert garden has a subtropical ambience thanks to the ornate asparagus fern. This customary name is somewhat deceiving because the asparagus fern is not a fern at all; but a member of the Liliaceae, or Lily family.

Growing these ferns in containers is easy and low maintenance.  This plant develops large tuberous roots and can become potbound in a relatively short period of time.  Asparagus Ferns are vigorous, fast growing plants that can take extreme heat as long as it receives regular watering.

top heat resistant arizona plants
asparagus fern tropical looking asparagus fern with berries

To encourage new growth I give our asparagus ferns a trim every so often.  In the photo above you will notice several green berries that will turn red by winter.  Since these plants are dioecious, not all of your asparagus ferns will grow berries.

What does dioecious mean? Plants that are dioecious have their male and female parts on separate plants. Both male and female plants must be present for pollination to occur. Asparagus Ferns are toxic to cats and dogs.  Contact with the skin may cause dermatitis so I recommend wearing gloves.

heat tolerant Fern in Arizona desert plants
Asparagus Fern in pots and containers

From a distance, the asparagus fern, Asparagus densiflorus, looks very soft and delicate. This can be attributed to its fine, needle-like leaves.  Make no mistake, putting your hands into an asparagus fern will give you little scratches.

Asparagus Fern is native to South Africa and is an evergreen perennial that is commonly used as a groundcover or in hanging baskets for its showy foliage.

Asparagus Fern and orange honeysuckle in planters
Arizona garden with asparagus fern – tropical plants

An easy way to propagate new Asparagus Ferns is by division.  Using a large serrated knife, you can easily divide up the root ball into half or quarter sections for more new plants.

tropical desert plants in arizona
asparagus fern plants in the Arizona heat

The photo above is one of our potted asparagus ferns that is located in the full Arizona sun.  Other containers are nestled in part shade.  All of the plants are growing well with my only complaint being I need to plant more!

Yellow needles develop on asparagus ferns for different reasons such as rapid temperature change, under watering, over watering, spider mites and possibly a change in light.  Your asparagus fern will need less watering during winter and in low light conditions.

Arizona heat tolerant asparagus ferns in pots
growing asparagus ferns in part shade

Asparagus ferns can be trained to grow as a vine or cascade down a hanging planter. Note:  Sprenger’s Asparagus has been declared a noxious weed in Florida, Hawaii and New Zealand.   Listed as a Class One Invasive by the Florida Exotic Pest Plant Council’s Pest Plant List (FLEPPC).

We love Asparagus Ferns and have grown them in hot, hot Arizona for years with no behavior problems.

Red Geraniums made # 7 in my top Ten Heat Resistant plants for southern Arizona

Zonal geraniums can last for years with the right growing conditions.  The red geraniums pictured in this article are the first plant my husband and I acquired when we were married.    They are very unique and add a velvety, radiant color to our desert garden even with the record-breaking 2012 temperatures.

This red flower is called a zonal geranium.  What is a zonal geranium?  Zonal geraniums are the genus Pelargoniums, and are NOT true geraniums. This species of flowering plants work well in Arizona and Texas because they are drought resistant, perennial and heat tolerant.  Zonal geraniums originated from South Africa and have become very popular as bedding and container plants.

Important fact:  Geraniums, Pelargoniums, are poisonous to dogs and cats.  If your pet eats a geranium contact your local veterinarian right away.

Zonal Geranium in Arizona
planted zonal geraniums in Arizona

I’m always on the lookout for a plant that adds a softness to a thorny, spiky desert garden.  Amazingly, a red geranium can thrive almost as well as a cactus.  We have several throughout our Arizona yard that are either in full sun or sparse shade.  All of our zonal geraniums are doing well; but, the ones with semi shade have larger leaves and more flowers.

zonal geraniums bedding

Caring for geraniums is easy:

  • They love the sun but do well in sparse shade especially with high temperatures
  • Plant Pelargoniums when there is no danger of frost, they do not like the cold
  • In the fall plants may be dug up and brought indoors by a sunny window away from your dogs and cats
  • Water geraniums when the top 2 inches of the soil feels dry
  • Zonal geraniums are critter proof and virtually insect free 🙂
heat resistant geraniums
hanging basket of Red Geraniums in Arizona

Pelargoniums are low-maintenance and a great choice for xeriscape yards.  Grow your geraniums from seed or plant cuttings.

If your geranium has yellow or red leaves it is experiencing stress in some way.  The most common causes of red or yellow leaves are:

  1. your geranium – pelargonium is over-watered
  2. phosphorus deficiencies, are you fertilizing?  If it has gotten cooler at night and the temperature drops below 55 your geranium will not be able to absorb trace minerals.
  3. another possibility is too much sun
  4. or planted too close together

Too diagnose the problem simply look at the exact conditions your plant is growing in.

Red Geranium is a zonal geranium
Pelargonium is a zonal geranium

Even with the best of care a few leaves will inevitably turn yellow; simply remove them along with spent flowers.

In the fall temperatures drop and red leaves on pelargoniums are a sign that it is time to move indoors or to take cuttings from annual cultivars.

October is barely here and I’m already daydreaming about plans for a colorful, lush spring heat-resistant garden.