When you hear or talk about cacti, you spontaneously visualize a tall green central post with several other green posts emerging from and growing upright on its body. Some of you may know the name of this iconic cactus while some others may not – this is Saguaro cactus! Saguaro or Carnegiea gigantea belongs to Cactaceae family and happens to be the largest and most exquisite cactus in the United States. In this first part of this article, we’ll know more about this beautiful giant!
Although it has many other uses like for building fences, furniture and roofs, and as a food and water source for birds and even humans, and building nests for birds, it can also be grown as an ornamental plant, both indoors and outdoors. It also grows beautiful flowers which have got the honor of being the state wildflowers of Arizona. Saguaro cactus needs very little maintenance and hence you should consider giving it a place in your cactus collection.
Characteristics of Saguaro Cactus
Saguaro is native to the Sonoran Desert which consists of Arizona, California and Mexico. Some of the characteristics of saguaro cactus you’ll have to remember while growing it are as follows.
Perhaps the most unique characteristic is its shape. It features a central cylindrical body with several peripheral arms, known as ‘spears’, emerging from the body and growing upward.
Often saguaro grows lateral stems after around 75 years. Some of them don’t develop these arms at all in their life.
Saguaro has a slow growing pace (they take anywhere from 20 to 50 years to reach a height of only 1 meter (3.3 feet)) but has got a huge lifespan of more than 100 years.
It’s a huge-sized cactus attaining a diameter of 75 cm (30 inches) and height of 16 meters (52.5 feet). The tallest saguaro cactus recorded so far is 23.8 m (78 feet) tall.
The skin of saguaro is coated in a thick wax to prevent water from escaping through transpiration.
Saguaro spines can be very sharp and can grow up to 1 mm (0.03 inches) every day and can attain a length of 7 cm (2.8 inches). Hence curious kids and pets should be kept away from saguaro. The plant stops growing spines after its first growing season.
Saguaro has a single taproot, extending up to around 5 feet inside the ground to reach the groundwater. The rest of its root system is located close to the surface, around 3 inches below the ground to collect rainwater.
After collecting the water, saguaro doesn’t use it immediately. Instead it soaks it up and stores it in its sponge-like interior.
If the plant gets more water, its skin expands to allow more storage space. This becomes possible by its interior ribs and exterior pleats that contract and expand with the plant as it stores and depletes water.
From April to June, saguaro develops creamy-white and waxy flowers that have a pungently sweet delightful melon scent.
The flowers open completely after the sunset and close the next midday. They start producing nectar after sunrise.
Animals like moths, bees, white-winged doves and hummingbirds are attracted towards the nectar and in turn help in the process of pollination. They get covered with pollens while sucking the nectar and then transport those pollens to other flowers.
However, the real help in pollination is done by long-nosed bats as the night blooming schedule of saguaro is a perfect time for bats whose brush-tipped tongues extract large amounts of nectar and the bats in turn bring about pollination. The bright white color of saguaro flowers is also helpful for the bats to spot them at night.
Saguaro flowers mature into attractive red fruits after pollination. They split open when ripened. The flesh is bright red and contains around 200 seeds.
The fruits are edible. You can eat them raw or boil and strain them to make sweet syrup which you can use in candies and jellies. You can even dry and preserve them or turn them into jams.
This cactus prefers growing at lower altitudes because it’s not very tolerant to cold temperatures and prolonged periods of frost.
How to Grow Saguaro
You can grow saguaro indoors as well as outdoors. Although it grows very slowly, it is very easy to grow and maintain, and doesn’t need much attention. However you should remember that if you live in colder climates or higher altitudes, saguaro may not be right for you.
When to Plant
Ideally you should start the planting process in late spring or early summer months.
Saguaro thrives in full sun; however, prolonged periods of hot and bright sun may burn it. Therefore while growing it outdoors, you should choose a site for them which would receive bright and partial light in the summer. It also grows well in a heated greenhouse.
While growing indoors, choose a spot before a south-facing or west-facing window.
Saguaro loves warm climate and cannot withstand frost conditions. It cannot enjoy temperatures dropped below 60° F (15° C). Therefore remember to bring them inside (if you plant them outside) in early fall. In the cold temperatures or winter, saguaro will be just fine at average room temperatures.
Since saguaro is a desert cactus, it prefers a neutral, loamy and well-draining soil. It’s a good idea to plant it in a potting mix that is particularly created for succulents and cacti or to add some additional grit to an all-purpose potting soil. Optimal growth can be achieved even by adding a top layer of gravel or pebbles, because this will reduce the moisture levels of the soil and help the cactus establish as it grows taller.
Similar to all other cacti, saguaro stores large amounts of water in its stem; so it can tolerate long periods of drought. However, if you water them sufficiently, they grow and bloom much better.
It’s recommended to avoid using a watering can or any overhead watering device to water saguaro. Since the plant’s roots are near the surface, such a watering technique may cause overwatering. Instead you can funnel a small hose into the ground surrounding saguaro (around 5 feet away from the main body of saguaro) and soak the ground around 1 foot deep.
After planting, it’s recommended to avoid watering for around 2 weeks. During the summer months i.e. from May to October, saguaro will need a deep watering once every 2-4 weeks.
During its growing season i.e. from late March to September, this cactus needs regular watering. During its dormancy period i.e. in winter, you can water it once or twice per month or can avoid watering altogether. The frequency of watering depends directly on the temperatures in which your saguaro is growing.
Regardless of what climate or season is, you always should check the soil before the next watering. It’s recommended to let the mix dry out slightly before you water it again.
To check if your saguaro has or hasn’t got enough water, check its exterior pleats. If they have a space of less than an inch between each two pleats, it indicates that the cactus is underwatered. You can even check its skin. If its skin is not firm, it needs more water.
As such saguaro doesn’t need fertilizers often. However, you can feed it once a year in spring. Using cactus food as a fertilizer is also fine as it can help the cactus to complete their growth cycle. But if you want to encourage growth, you can use a light liquid fertilizer once every 2-3 weeks during its growing season. Overfertilizing or fertilizing during the dormancy period should be avoided.
The most common pests that can attack saguaro are scale insects and mealy bugs. If you notice any signs of infestations, you should immediately quarantine your saguaro and wipe it carefully with a clean cotton rag dipped in rubbing alcohol. Using organic insecticides or pesticides regularly can also prevent these infestations.
Saguaro can often fall prey to bacterial infection. But the infection can be easily treated by excavating the infected part and applying a mixture of 10% bleach and 90% water to it.
How to Repot Saguaro
The success rate of saguaro repotting is inversely proportional to the size of the plant. This means that the smaller (younger) the plant, the higher are the chances of its survival. Actually, it’s virtually impossible to kill a saguaro which is two feet or shorter. On the other hand, very large saguaros of height 25 feet or taller hardly survive. There are several reasons for this. One is their own weight which often causes crushing of tissues which in turn starts rot. Secondly they have to be planted so deep that new roots cannot reach the surface. And thirdly the trauma of repotting may speed up conditions within the plant that would have killed it without repotting.
While repotting a reasonably sized (less than 20 feet of height) saguaro, careful handling, a perfect planting spot and appropriate watering practices are the keys to success.
Careful Handling: This has two factors – protecting the saguaro from damage and protecting yourself from the saguaro. For saguaros shorter than 8 feet, you can do the relocation on your own if you’ve many strong and willing friends to help you. However, you should be realistic about your abilities since a healthy saguaro can weigh as much as 100 lbs. per foot of height.
For exceptionally large saguaros and saguaros more than 10 feet tall, it’s recommended to take help of a professional.
If you want to move the saguaro from one property to another, you’ll also have to obtain a trip permit from the Arizona Department of Agriculture. Without the permit you may incur a fine or confiscation of the plant.
To do it carefully, you should first dig around the plant at around 30 cm (1 foot) away from it until you find several roots. You should cut the roots at the bottom of the dug hole, keeping most of them intact. Now remove the plant gently and cut any unhealthy parts with sharp pruning shears. Shorten the taproot to a diameter of around 3”-4” so it’ll be strong enough to support the plant. New roots emerge from the fleshy ring around the roots’ woody core. Hence it’s important that your cuts be clean.
Before repotting, you should leave the plant to let the roots dry for a few days. In hot dry climates the cuts usually dry out within a few hours. But if it’s cold and humid, but you can’t wait for better weather, you can apply a 10% bleach solution to disinfect the cuts and soil sulfur to accelerate drying.
The site where you’ll replant your saguaro should be well-draining, safe, without overhead obstructions and accessible if in the future removal becomes necessary.
Before digging a hole in such a site, you should first call utilities free Blue Stake service to avoid cutting an electric line of telephone cable.
The hole should be a few inches wider than the widest dimension of the roots. Its depth will depend on the overall size of the plant.
You should not water your saguaro immediately after relocation. This is because the stress of transplanting may cause some rot in the roots. If the soil is dry, the rot won’t develop further. Then you should give the plant another 6 months for its best chance of survival.
If, after this period, the plant looks dehydrated, you can water it by digging a small shallow well near it to which you should add not more than 2-3 gallons of water if the plant is large and somewhat less if the plant is less than 8 feet in height. Then give the plant around 5 gallons of water once a week. However, never start watering in winter; wait till the temperatures rise to the 90s’ range.
But if the plant is not dehydrated and its color is looking good, there is no need to water it ever!
The easiest and safest way of propagating saguaro is from seeds, although it will give results after a long period. However, you can prepare the propagation environment in just a few minutes.
Take a small to medium-sized container with drainage holes and fill it with potting soil. This can be any well-draining mix or just the one suitable for growing succulents and cacti. Now make several tiny holes in it with a sharp pencil with a gap of 1 inch between them and bury your saguaro seeds in the holes. Now cover the container with plastic wrap and poke some small holes in the plastic wrap.
Place the pot in a warm spot that will receive enough light but will protect it from extended periods of full and direct sunlight. Water the seeds once every 10 days. Remove the plastic wrap after 4 to 6 weeks. Once this period is over, you can water the cactus once every month.
Tiny saguaro cacti will start emerging in around 1 or 2 years. They can be moved in their own pots.
Growing your own saguaro is sheer joy. I’m sure, you’ll enjoy even more when in the second and last part of this article, you’ll read about some amazing forms of saguaro created from cresting. Till then, don’t forget to share your opinions and bye bye!