In contrast to group planting, individual cactus are more frequently used in desert environments. The majority of plants, including cactus, look better when planted in groups, though.
Cacti species frequently colonize a region in the wild. In these colonies, plants of all ages and sizes are arranged in a haphazard fashion with varying distances between one another. By choosing and planting cacti of one species in a range of sizes, you can mimic the growth of such a natural colony.
Urban gardens benefit most from cactus groups of small to medium size. A small number of plants arranged in odd-numbered groups of three, five, seven, or nine are the most aesthetically pleasing and in scale with the majority of house landscapes.
Cactus clusters with species that have rounded or spreading forms are the most beautiful. These include the devil’s tongue, fishhook, and golden barrels.
Cactus in low, spreading shapes can create a pleasing “clustering” look in a landscape. By basal branching, hedgehogs, claret cups, and flying saucers spread. They all have lovely flowers.
Choose a spot for your cactus colony where there will be shade during the hotter parts of the day and in the late afternoon. Any area where heat is reflected, such as along south and west facing walls, should be avoided. With modest sun protection, the majority of imported cactus species, like golden barrels, thrive well. A palo verde tree’s gentle shade provides the perfect planting location.
It might be necessary to visit numerous garden centers to find plants of a single cactus species in a variety of sizes. Even though they will cost more, it’s crucial to include a small number of larger specimens to mimic the randomness of an actual colony.
Cactus can best be planted in the summer. High temperatures and monsoonal rainfall will help cacti establish and develop more quickly.
Keep in mind the final size that each cactus will grow to. Cactus can be a little close together. Just keep in mind that if they get too crowded, some may need to be eventually removed and relocated.
To get ready to plant the colony, till the soil. If there is a hardpan of caliche present, it should be removed or another location should be picked because cacti like well-drained soil. Use a spade to till the soil about a foot deep. As you progress, remove stones and rocks. Do not modify the soil with organic matter. Our native desert soils are best suited for cactus growth. Dig holes big enough to fit the cactus’ root systems after removing the earth, then plant it and add the removed soil back in.
Right after planting, properly water the soil. Irrigate once every three to four weeks throughout the hot summer after this initial watering. Water only if normal rainfall is absent in the winter, and even then, only sparingly. Overwatering causes more issues for cacti than underwatering does.
Tips on plantings and growing cholla cactus
Mark Sitter and Chris Monrad, two cholla cactus enthusiasts, offer advice on how to cultivate and plant the plant.
- Chollas are significantly simpler to plant while they are young.
- If you wish to plant a cholla, make sure the area is big enough for its eventual growth. If it becomes too large, transplanting won’t be a good idea.
- Cholla shouldn’t be planted close to a path or any other place where people or animals could bump into it.
- A cholla can benefit from the summer rains by being planted in June, allowing it to grow swiftly.
- To help it develop even more quickly, water it. They’ll really take off with only a little more assistance with passive water gathering, according to Monrad.
- May, June, July, and August are the months without a “R” that Monrad uses to apply a time-release cactus fertilizer.
Cochineal scale insects
I have a cochineal infestation on a prickly pear in my backyard. Does that require medical attention? When do these guys leave on their own? Do they even pose a threat to the cactus?
A: Prickly pear cacti’s sap is sucked by cochineal scale insects (Dactylopius species), and big populations of these pests can weaken the plants. Treating them is not required. The females produce cottony wax to cover themselves and their egg masses, which makes them visible and partially shields them from the environment and insecticides. The eggs develop into crawlers, which feed for around three weeks before settling down and going motionless. They disperse their population on cactus plants during the crawler stage. Once established, they begin to create the waxy substance that protects them from weather and predators. Every year, several generations are created. Although these insects feed on the plant, the damage is typically minimal. You can remove the worst pads from a plant that is heavily infested and displaying indications of deterioration and throw them away (always prune at the joints). Use a high-pressure hose to blast the rest of the plant. The insects should become more vulnerable as a result. Next, apply an insecticidal soap or horticultural oil to the scale that has been exposed. The negative impacts on beneficial insects will be reduced by these low-toxicity insecticides. Since the crawlers are the weakest link in their life cycle, it is better to treat them when they are active. For the first generation of the year, this frequently happens in the late winter or early spring.
Can I dig up a saguaro?
A saguaro in my yard contracted a sickness, died, and then fell down. I now want to dig up one that is in the yard of a different house I own. Can I transport the saguaro that is still alive to the yard where the saguaro died by digging it up?
A: To move or dig up an established saguaro, you often need some form of permit from the city or possibly the state. So make sure to double check it before relocating the plant, otherwise you risk receiving a fine. Your saguaro appeared to have bacterial necrosis, a common condition that can spread to the cactus’ roots. In some instances, the diseased area can be removed to prevent it from spreading to the roots.
Black splotches on prickly pears
One of my prickly pears has black splotches all over it. The pad seen in the accompanying photo is an average pad, however there are many worse ones at the bottom of my garbage can. I am aware of how nature works in balance and the advantages of coexisting, yet this plant had to be removed since it was an eyesore. I believe that a fungus is the root of the issue. It should be swapped out for an Engelmann’s prickly pear. Additionally, some of the pads appear to have had their outer edges eaten by a rat. If it is a fungus, can you identify it? How long does it linger in the soil? If it persists, can I apply a fungicide to the soil to prevent the fungus from spreading to the young prickly pear? Is it more likely that a packrat or a Harris’ rock squirrel—both of which we have—caused the chewing damage?
A number of insects or diseases can lead to lesions on prickly pear, but the most prevalent is Phyllosticta pad spot, which is persistent in our region. Given that it is indigenous to the desert and widespread, I am concerned that no amount of fungicide would be able to eradicate this. It is challenging to control and spreads by releasing spores that are carried by the wind and rain. As you already do, severely infected pads or plants need to be removed from your landscaping. There isn’t much else you can do. Any of the local rodents or javelinas, if you have them, may have caused the chewing damage.
Fungus, mildew and rot can take a toll
A: I’m hoping The Garden Sage can assist me figure out what went wrong with my Beavertail Cactus, which is three years old. It is not irrigated and is planted on a 3-foot high berm. I only noticed it bending over this week, and upon closer inspection, I saw that the stems are rotting. The rot appears to be advancing into the pads from above. The ground is arid. I am unable to explain the issue. Now what?
A: Root rot is most likely the cause of the decaying that is occurring from the base up. Although excessive watering may be a factor, the plant was probably exposed to a bacterial pathogen through a wound of some kind. The entry site can be if there are any wounds from insect bites, pruning, or other abrasions. The infection might have easily originated during the monsoon season when we had a lot of rain, even though the soil is dry now. If it seems like the entire plant is harmed, you might want to give up and replace the cactus with something else that is more resistant to the environment it was exposed to.
Growing prickly pear
What would be the best way to try to grow them? I have a jar of prickly pear seeds that were harvested from prickly pear fruit a year or two ago.
A good article on this subject was written by my retired colleague Jack Kelly and is titled “How to Propagate Agaves and Cacti from Cuttings and Seed.” You can find it online or on our website by searching for the title or AZ1483. The publication is too big for this area, but to get you started, here is the first section. If you’re interested, you can get the remainder for free!
Start with brand-new, clean seed every time. The seed should be planted in shallow, broad containers with sufficient drainage, air, and some organic matter to hold moisture and nutrients. The best mixes are those that typically include 50% inorganic material, like perlite or pumice. Sphagnum peat or organic material that has been properly composted should make up the other half of the mixture. Avoid using animal manures since they could prevent seedling germination. 65 to 70 degrees at night are ideal for optimal germination and growth. Spread the cactus seed uniformly across the pot’s surface, and then, taking care to avoid burying it too deeply, lightly cover with coarse sand. Put the container in a water-resistant tray and fill it with water until it is half full, enabling water to seep into the container’s bottom and moisten the medium within. Place the seeded pot outdoors in a well-lit, warm area, but out of direct sunshine.
Bugs enjoy tasty prickly pear
My prickly pear cactus pads have some odd marks on them, can you explain? Please explain the cause and the appropriate course of action.
A: One of the most prevalent cacti in our region is the prickly pear cactus (Opuntia species). A plant bug species known as a cactus plant bug is responsible for the devastation you are currently witnessing (Chelinidea vittager). They are close relatives of the leaf-footed bug and resemble squash bugs in size and appearance. They eat the cacti by sticking their mouthparts through the surface of the plant and sucking off the sap. You are only witnessing little bodily injury as a result of this damage, which poses no severe threat to the plant.
Watch out for that saguaro!!
A noticeable tilt in the top reach of the main stem (trunk?) of my saguaro has appeared over the past few years. At the inflection point, it has already begun to fracture. Should I be worried that the top might fall off completely? If it does, could the entire saguaro be brought down? Should I get the saguaro topped if this is going to happen?
A: Indeed, you should be concerned, particularly if everything close is at risk of being harmed. According to the pictures you gave, it appears to be dangerously close to your driveway. Because they are so hefty, saguaro cactus could easily cause harm to you or your property. I advise hiring a trained arborist to visit your property and provide you with an estimate of the risks that may exist, your options, and the cost to address the issue. To ensure you receive the greatest pricing as well as a second and third opinion, you might obtain multiple estimates.
Gnats feast on saguaro fungus
In my parents’ yard, there is something encroaching on a saguaro cactus. But I was curious as to your knowledge of the “black stuff.” I found it strange that when I disturbed it, some gnats flew from it.
A fungus is developing on the dug cactus pieces that were thrown out of the hole and adhered to the spines. The fungus gnats you saw flying out of the fungus are simply feasting on that; they pose no threat to the cactus.
Thirsty or dying of thirst?
Is my saguaro dead or dying? It is eight years old and roughly four feet tall. It was moved two years ago from its previous location, which was only a few feet away and facing the same direction. It doesn’t have any drips and only gets wet when it rains. I really could use your assistance in deciding whether or not I should replace it.
A: Your saguaro appears to need water. Cacti should be watered 12 to 18 inches deep once every 10 to 14 days in the summer and once every 21 to 28 days in the spring and fall. You can stop the irrigation if the temperature at night falls below 60 degrees Fahrenheit. The majority of cacti can survive the winter without additional irrigation. Another suggestion, though it’s too late in this case, would be to give recently transplanted cacti some shade cloth. Any plant that is being transplanted experiences stress, and providing shade from the sun is one approach to lessen that stress. Cacti that have received excessive sunburn turn yellow, and in some cases, the damage might be fatal. If you can give the irrigation, it appears as though your plant will survive, but only time will tell.
Saguaro with termites
A: The base of my saguaro and the tree next to it appears to be covered with a brown stuff. Termites, are these? If so, how can you proceed or is it already too late?
A: It’s difficult to tell from the photo, but the saguaro might have termites. In older saguaros, when there are dead woody areas, desert encruster termites (Gnathamitermes perplexus) will typically inhabit the outside. They bring their mud environment with them, so the base of the cactus may appear to be caked in mud. If you remove a little of it, the tiny white termites may flee for safety. The live part of the cactus is protected from injury because termites only feed on dead wood.
Protecting your cactus
A: Six years ago, at an outdoor wash area where I live in the Tucson Foothills, I planted three San Pedro cacti. Every winter, at least seven days can easily pass with temperatures below freezing. Can I leave the green exterior frost protection drop cloths I bought from Home Depot over each San Pedro cactus from late December to mid-February without harming these plants? It is getting harder and harder to cover and uncover each 5-foot-tall San Pedro cactus. When should outdoor San Pedro cacti be covered and shielded from frost damage, according to you?
A: If the ice cloth lets light through, you can leave it on without a problem. In our region, frost danger often lasts from mid-November until late February. Of course, this is only a recommendation. The risk of frost is highest from mid-December to mid-January and is closer to 10% at the early and late ends of this period. When local weather forecasters indicate a risk of frost, I advise covering delicate plants. As you are aware, there are certain winters that are rather mild and allow you to avoid covering your plants, and then there are years like 2011 and this one that are colder and keep us on our toes.
Non-flowering Christmas cactus
A Christmas cactus I own did not bloom during Christmas last year. Despite being incredibly vigorous and lush, it lacks blossoms. Epsom salts: Should I use them? I was informed that would be beneficial.
A: Epsom salts can enlarge a plant’s blooms, but they won’t result in flowers. Your plant could definitely benefit from frequent fertilizer. Fertilizing is typically required in the spring and summer. After that, allow the plant to rest for a bit in October and November. After nightfall, stow it away in a closet and leave it there. Only allow it to have indirect light when you take it outside throughout the day. Put it in direct light once the buds start to form, and it should start blooming in time for Christmas. A Christmas cactus is a tropical plant, not one that grows in a dry desert. Although it prefers moist soil, it dislikes being overwatered. Putting your plant in a slightly bigger pot might also be beneficial.
Getting flowers on toothpick cactus
A: My toothpick cactus has produced five blossoms for the first time in 12 years. If it’s possible, how would I go about propagating a toothpick cactus?
A: Cuttings or seeds can be used to spread the toothpick cactus (Stetsonia coryne). To take a cutting, simply use a sharp knife to slice off a portion of the top of the stem at a 45-degree angle, keeping the parent plant’s wound dry. Its dimensions might range from three inches to six feet. The cutting should be squared off, dusted with sulfur and/or a rooting agent, and left in a dry, airy area to develop a callus. Depending on the weather, this may take one to four months. The best time of year to complete this portion is from August through October. Next, plant the cutting in a typical cactus container with a standard cactus mix composed of 50% pumice or perlite and 50% peat or compost.
Plant it deeply enough to prevent tipping, then add fine gravel to stabilize it. Water the mixture every a month or so to prevent rot while preventing complete drying out. Place the pot somewhere bright.
Even if some take longer, the cutting should root in a month or two. The cutting can be transplanted after it begins to show signs of active growth into a larger pot or directly into the ground where you want it to grow. If you use a one- or two-gallon pot, there is no rush. They can develop there for as long as a year.
Think about a Christmas cholla early
The flat-leaved succulent with spectacular flowers that most people associate with Christmas cactus originated in Central America.
However, there is a different variety of Christmas cactus that grows in the Sonoran Desert and is known by the scientific name Cylindropuntia leptocaulis. It’s a cholla for Christmas.
Director of Desert Survivors Native Plant Nursery Jim Verrier refers to it as “One of our few small chollas, and a wonderful plant.
The red fruit on the pencil-thin joints, which develop from November till as late as March, is how it gained its name.
The only cholla that regularly bears fruit in the winter is this one. It has a diameter of two to three feet and a height of two to four feet.
In the spring, tiny blooms that range in color from creamy white to yellow to green blossom. Little green fruits start to grow when they ripen and fall off in May. The fruit begins to turn purple and then scarlet around November.
The best places for Christmas cholla to grow are in low-traffic areas far from humans and animals because it has both long and little spines. Give it room because portions frequently fall off and new plants can be easily established.
The Christmas cholla is simple to plant, develop, and spread because it is a native of the Tucson basin.
It can be found at nurseries that focus on native or desert plants. Verrier thinks that spring is the ideal season for planting.
Take a 3- to 4-inch piece from a Christmas cholla if you know someone who has one and plant it.
“Gene Joseph, a co-owner of the Plants of the Southwest nursery, advises planting a small clipping in well-draining soil in a container.
You may plant it in the ground after about a year, and it will develop into a resilient, drought-tolerant, and sun-loving cactus, according to Joseph.
Although chollas aren’t particularly common landscape plants, Joseph thinks the Christmas cholla is worth including in the yard.
It’s a fantastic little specimen, he says.
It provides you with a really lovely floral display, is practically carefree, has bright fruit in the winter, and they feed the birds that are active at this time of year.