Are Cannabis Plants Perennial?

As a cannabis grower, you may be wondering if it's possible to continue cultivating the same plant year after year. In botany, a perennial plant is defined as one that lives for more than two years. In this article, we'll examine whether cannabis can be classified as a perennial plant and discuss the techniques that growers can use to achieve a continual harvest, even if their plants don't qualify as perennials. We'll also consider the potential benefits and drawbacks of cultivating cannabis as a perennial, and explore whether it's a feasible option for those growing the plant for recreational or medicinal purposes.

What is a Perennial Plant and What are the Advantages of Growing Cannabis as a Perennial?

Perennial plants require less maintenance and can produce a more consistent yield over time, making them a popular choice for many growers. Cultivating perennial plants saves time and resources by eliminating the need to purchase new seeds or clones and avoiding the delicate stage of growing a sapling. Additionally, for those growing cannabis for its psychoactive properties, cultivating perennial plants can also skip the step of determining the plants' sex, as female plants produce higher levels of THC.

Most Cannabis Plants Are Annual

Most cannabis plants are annuals, meaning they complete their entire life cycle in a single growing season. This is partly because cannabis plants typically grow from seeds rather than forming a root system that can survive the winter and regrow the following year, like perennials do. Cannabis plants typically begin their life cycle in spring as seedlings, flower during the summer months, and are ready to be harvested in the fall.

While it's possible to attempt to cultivate cannabis as a perennial, doing so may compromise the plant's health and productivity. This is because the plant has evolved to follow a specific growth cycle, and attempting to alter this cycle may cause the plant to struggle. However, the fact that cannabis is a weed means it's well adapted to self-sowing, which helps explain its abundance in certain areas in the wild.

The Typical Cannabis Cycle

Cannabis plants can also be cloned, allowing growers to cultivate clones of the same plant for an indefinite period of time. However, the mother plant must be kept in constant light to prevent it from budding and producing additional flowers. In most cases, cannabis plants thrive in well-drained soil with full sun, but they can also grow well in a variety of climates. Without human intervention, wild cannabis plants typically only survive for one season, lasting between five to 10 months.

Most cannabis strains are photoperiod sensitive, meaning that whether they flower depends on the amount of uninterrupted darkness they receive. If they receive too much uninterrupted darkness, they may not flower at all.

It May Have Once Been a Perennial

Cannabis is dioecious, meaning it is a gendered plant. Other dioecious plants include ginkgos, willows, and African teak. Some botanists believe that cannabis plants may have once been perennial and may have changed as the climate in which they grew changed, forcing the plants to adapt. Based on this theory, it is feasible that perennial cannabis plants may be found in tropical and sub-tropical areas. These plants would flower during the fall before entering a period of slow growth. In the spring, they would return to a vegetative growth stage before flowering again in the fall.

Growing Conditions Are Also a Factor

The growing conditions for a cannabis plant can also significantly limit its ability to function as a perennial. In areas with cold winters, frost can kill the plant unless it is grown indoors in a highly controlled environment.

In areas with more temperate climates, it is more common for cannabis plants to behave like perennials.

Most anecdotal evidence of wild cannabis plants that continue growing year after year tends to be from these regions. However, there are certain strains of cannabis that have adapted to thrive in even the harshest climates. An example of this is ruderalis, which can complete its life cycle quickly and survive Siberian winters despite the sub-zero soil temperatures.

Perennial Cannabis Plants May Exist

Although the majority of cannabis plants are annual, some companies claim to have developed cannabis seeds that can grow the plant for decades. However, these claims are often unsupported by concrete testing and information, and the prices for these supposed perennial seeds are often exorbitant.

One example is BC Seeds' Forever Buds, which are genetically modified but come with a high price tag and minimal evidence of their ability to produce perennial plants.

These buds are reportedly expensive to purchase, with the company claiming that they will last for decades. However, reviews of the buds are mixed, with some people reporting positive experiences and others expressing skepticism about their effectiveness. If you are interested in trying to cultivate perennial cannabis plants, this may be an option to consider, but it is important to be aware that it is a risky and costly endeavor.

You Can Treat Your Annual Like a Perennial

There are several methods that allow you to treat your annual cannabis plant as a perennial. In nature, cannabis plants often retain enough of their leaves between cycles to enter an additional vegetative cycle when the seasons change, potentially repeating this process for up to a decade. However, the caveat is that these methods may not produce the same quality buds and flowers as an annual cannabis plant.

Turn the Plant Into Cuttings

One method for treating your annual cannabis plant as a perennial is by turning it into cuttings.

To do this, snip off flowers as you would for cuttings, including in the areas where you would normally harvest. Immediately after snipping off the cuttings, place the plant back on the vegetative nutrients and schedule you use for the vegetative growth cycle.

Your goal should be to get the plant back into a vegetative growth state, although this can be difficult to achieve. If you are successful, turn the plant into as many cuttings as possible.

This is a better option than allowing the plant to re-flower, as the quality of the buds will be higher. If you simply follow these steps but allow the plant to re-flower instead of turning it into cuttings, the resulting flowers will likely be of lower quality, as the plant will have used all its nutrients and energy in the initial flowering stage.

Avoid Producing Seeds

Another option for treating your annual cannabis plant as a perennial is to grow it as you normally would, but prevent it from producing seeds. Plant scientists have found that when a cannabis plant is fertilized and produces seeds, it also produces a hormone that causes the plant to die. By avoiding seed production, you can prevent the release of this hormone and allow the plant to grow for another year.

Anecdotal Evidence to Treating Cannabis as a Perennial

There is a significant amount of anecdotal evidence online from forums and other sources suggesting that it's possible to treat cannabis as a perennial successfully, although this may require additional effort. This evidence tends to be for indoor plants rather than outdoor ones, although there are exceptions.

Many people have reported that they've been able to get their indoor cannabis plants to re-enter the vegetative phase and then take clones from the plant. Some have noted that the resulting cannabis plant has reduced potency or taste, while others have reported no differences at all.

Based on the conflicting anecdotal evidence, it's possible that the success of treating cannabis as a perennial depends on growing conditions, cannabis strains, or the health of the specific plant. The anecdotal evidence does seem to suggest that growers in temperate climates may have better luck with this approach, and even indoor plants in areas with freezing temperatures may not fare well after their first season.

Overcoming Nature Typically Wastes Resources

While there are methods for attempting to treat cannabis plants as perennials, many growers do not recommend these approaches. In most cases, the results are not as good as if you simply planted a new cannabis plant for the year.

Additionally, you may find that you spend more time and resources trying to trick the plant into growing again than you would on a new plant. The changes in lighting necessary to use many of these methods can also add unnecessary stress to the plant, potentially reducing the quality of the buds and flowers and leading to an earlier death. In many cases, the reduced quality and increased time and resources make it more economical to simply grow a new cannabis plant.

Forced Perennial Success Depends on the Strain

There is some evidence that the likelihood of successfully treating a cannabis plant as a perennial may depend on its strain.

Cannabis sativa plants, which are known for being large and tropical, are more likely to be successfully treated as perennials. On the other hand, cannabis indica plants, which tend to be smaller and have a shorter lifespan, are less likely to be successful when treated as perennials.

The light requirements for cannabis sativa plants also tend to be more conducive to perennial growth. For example, certain strains of cannabis sativa that grow in the tropics may only need about 12 hours of light to stop flowering, allowing them to flower when they receive less than 12 hours of light per day and bypassing the need for a regular vegetative period.

Why You May Want to "Re-veg" the Cannabis Plant

Despite the additional time and resources required to re-veg a cannabis plant, there are some popular reasons why growers choose to do so.

The most obvious reason is that re-vegging allows you to avoid buying new cannabis plants or seeds and starting from scratch with the growing process.

Some growers may also want to re-veg a particular phenotype because of its quality and preserve it by re-vegging if they forget to take a clone before the plant enters the flowering state.

Additionally, re-vegging may be a good option for growers who want to get rid of the mother plant but still have a steady supply of clones. Re-vegging allows them to do this without dedicating significant space to the mother plant.

Instead of Perennials, Try Staggering

If you want to achieve continuous harvesting of cannabis, you may want to consider introducing the staggering technique. This involves planting seedlings in batches, allowing you to germinate and plant the first group of seedlings and then repeat the process in a few weeks until you have filled all your available space. This will allow you to harvest cannabis every few weeks during the appropriate season, even if the plant is not a true perennial.

Calculating Staggering

To determine the best staggering schedule for your cannabis growth, consider your needs and available space. For personal consumption, you may want to plant just one cannabis plant per batch, with several months in between. For commercial growers, larger batches with shorter periods between germination, such as around a month, may be more suitable.

Start by calculating how many cannabis plants can fit in your space, and how long you want to grow them for. Then, consider the maturation period of your chosen cannabis strain and how many full growth cycles each plant location can undergo in a year. Use this information to determine how often you want to harvest, and divide the number of harvests per year by your available space to find out how many plants to include in each batch. Remember that cannabis flowers will degrade if left alone for too long, so it's important not to grow more than you need if you are growing for personal use.

The Takeaway: Cannabis Plants Are Annual

When it comes down to it, cannabis plants are annuals. They typically only grow for one season and then die off after harvesting. There is lots of anecdotal evidence of cannabis lasting more than one season, including in nature, but this is not common and frequently not proven.

You can still achieve a consistent harvest by staggering your planting schedule and germinating new seedlings in batches over the course of the growing season. This way, you can enjoy fresh, high-quality cannabis throughout the year without the added effort of attempting to make your plants behave like perennials.