When growing cannabis, there is a big difference between outdoor and indoor cultivation. Most growers prefer one or the other and have valid reasons for their preference.
There are pros and cons for both growing locations. Indoors provides a more controlled environment and the ability to easily manipulate light intensity, temperature, and humidity, as well as supplement the environment with additional carbon dioxide. Outdoors, plants are more susceptible to the elements. A passing hail storm or strong winds can have a devastating effect that the grower didn’t plan on. Pests and thieves also are a valid concern outdoors.
These uncontrollable factors make predicting the harvest and ultimate outcome of the outdoor grow less certain than an indoor grow. Outdoor cultivation usually falls during a clearly defined grow season in North American temperate zones, while indoor grows can occur year-round. These are the negative aspects of outdoor growing that warrant consideration on the part of the grower, but there are many positive factors of outdoor growing as well.
The Benefits of Outdoor Growing
On the plus side, outdoor cannabis cultivation often allows the grower to increase the number of plants grown, as well as the space in which to grow them. Another huge advantage to the outdoor grower is that they don’t have to invest in expensive lighting system or pay lofty electric bills every month—they’re able to harness the sun’s natural rays, and you can’t improve on Mother Nature when it comes to growing plants.
To ensure a successful harvest, outdoor cannabis growers should start their plants during the spring once the temperatures begin to climb and the days grow longer. To predict the eventual harvest as best as possible, growing clones or seedlings from feminized seed will allow the plant count to remain constant, with no males to remove. Planting in the spring will allow for several months of growing, and outdoor plants can grow very large, so be sure to provide enough room between the plants if planting directly into the ground. Topping is often more necessary outdoors to limit height and promote robust lateral growth—which is often substantial compared to plants grown indoors.
Growing plants directly from the earth makes it easy to provide nutrients to the plants from compost. If you’ve never made your own compost and want to grow outdoors, give some serious consideration to making this superior soil additive yourself for free. Topping off soil with compost throughout the grow will allow your plants to flourish with natural, organic material. While most growers choose to grow organically because of the superior terpene experience and flavors that result, some growers prefer to use alternative fertilizers and additives because a constant reliable source of compost is not easily available. There is much to be said for some of the commercially available additives available from nursery companies like Fox Farms and others. These products are almost completely organic—as organic as you can get out of a bottle.
You may notice that your plants begin to grow at a slower rate outdoors than they do indoors. As long as the plants are receiving at least eight full hours of unfiltered, direct sunlight per day, there is no cause for concern. The plants will soon grow at a faster rate and greatly increase in size. After summer solstice—the longest day of the year—daylight hours gradually begin to shorten. By summer’s end, the plants will have revealed their sex, which will be female if growing from clones or feminized seed. If growing from normal seed, the males will reveal their sex soon and should immediately be removed from the grow and destroyed because of the devasting effect they will have on the females you plant to harvest.
Once the garden contains only female plants, the flowering process will be slow at first and gradually pick up speed as the days continue to grow shorter.
Planning for the Harvest
Female plants differ from males by the presence of calyxes and pistils, which first appear at the juncture where branches meet the main stem. What was initially a few will soon grow into hundreds, then thousands of pistils, which appear to be white hair-like structures. The pistils and calyxes will begin to grow in clusters that are the female flowers. The largest flowers (colas) are located near the top of the plant.
Plants can increase quite a bit in height during the flowering phase of growth. When outdoor plants are at their peak in growth and bud development, they will consume more water and nutrients than at other times of their lives. Follow the feeding chart for the nutrients you use. Most cannabis growers do not feed the full amount recommended and scale back to about three-quarters the amount, with very good results. Many fertilizer and nutrient companies sell specialized additives to use at specific times during the growth cycles, so be sure to read the instructions. It’s not unusual to use three or four formulas during a grow. Most growers discontinue feeding nutrients for the final two weeks of growth. They slightly increase the amount of water given to the grow to flush residual nutrients from the soil and root systems of the plants. This helps ensure that the aromas and flavors of the flowers are expressed to their fullest potential.
The exact time to harvest an outdoor grow depends on some key variables like geographical location and the specific strains that are grown. Various growers often differ in opinion when it comes down to the perfect time to harvest cannabis plants. Plants harvested too early will lack full terpene development and lack full flavor and cannabinoid potency, while those harvest too late will also lack in optimum flavor and will have a heavier, narcotic-like effect when smoked.
Cannabis plants grown outdoors are typically ready to harvest in the fall, during September or October. Indica plants mature and are ready for harvest sooner than sativa plants. Some pure sativa strains will take as long as two to four weeks longer than a pure indica to mature. Hybrid strains will fall somewhere in the middle when it comes to harvest time, with sativa-dominant hybrids taking longer than their indica-dominant counterparts. The overall vigor and health of cannabis plants that are approaching harvest will take a downturn. Some of the leaves will begin to yellow and curl—and this is completely normal.
To determine when plants are at their peak for harvest, closely examine the flowers. As the plant ages, the flowers grow and swell until the calyxes (the pod-like structures from which the pistils emerge) reach maximum size. During the final couple of weeks prior to harvest, the flowers don’t increase as dramatically in size, but they continue to add to the sticky layer of trichomes (the small, transparent resin glands shaped like small mushrooms that appear on the flowers and small leaves near the flowers).
To determine the best time to harvest, let the pistils and trichomes be your guides. To examine the flowers up close, use an inexpensive jeweler’s loupe (a magnifying glass will do in a pinch). The loupe will allow you to see the pistils and trichomes much better. Most growers want to see approximately 75% of the pistils turn a reddish brown from their original bright white coloration. When trichomes first emerge from flowers, they are transparent, and they gradually turn milky, then amber, as they age. Most growers want to harvest when the majority of sticky trichomes are milky white or amber. Waiting until all the trichomes are amber is too long, and the plants are past their prime. Following harvest, the cultivator should hang the plants in a dark room with moderate humidity for approximately five to seven days for a basic cure.
Any cannabis grower—even seasoned professionals—should take pride in harvesting an outdoor crop. Being able to do so means that the plants received the proper care and pampering they require in a sometimes-unpredictable outdoor environment. So, when the last plant comes down, give yourself a pat on the back for a job well done!