Early-Season Outdoor Cannabis
Growing cannabis outdoors is one of the most rewarding experiences any cannabis cultivator can have, however, care must be taken during the early outdoor season to reap the maximum yields from outdoor plants come harvest time.
Although significant strides have been made toward efficiency and effectiveness in artificial horticultural lighting, there is absolutely nothing on Earth that compares with the power of the sun. Cannabis plants grown outdoors experience what Mother Nature has always intended for them: an abundance of light and fresh air. During the earliest part of the outdoor growing season, there are a few things cannabis growers should do to establish healthy plants. Hardening off, transplanting, supplying the proper nutrition for the early stages of growth/root development, and prevention/treatment of early-season pests are all imperative when establishing a healthy outdoor cannabis garden.
Hardening Off Cannabis Plants
Hardening off is the process of slowly acclimating young cannabis plants or seedlings to a new environment. In other words, hardening off is a method used by gardeners to gradually condition their plants to the comparatively harsh conditions of the outdoors. Please keep in mind “harsh conditions of the outdoors” is a relative term. Cannabis plants are supposed to grow and thrive outdoors. However, when a plant has become accustomed to the cozy, consistent conditions of an indoor garden or greenhouse, the conditions of the outdoors are relatively harsh and can literally shock a plant to death.
The average last frost date in a gardener’s geographical location is a good indicator of when plants can be safely transitioned outdoors with a lower risk of frost. The three biggest factors affecting a plant’s transition from an indoor to an outdoor environment are direct sunlight, wind, and temperature. Each of the three factors below can adversely affect cannabis seedlings and/or young plants when transitioning (hardening off) from an indoor to an outdoor environment.
Even plants grown under high-intensity discharge lighting will have a hard time transitioning into the power of the sun’s rays. Tender seedlings and young cannabis plants grown indoors must be gradually transitioned into sunlight. Start by placing the seedlings or young plants in a shaded area. After a couple of days in the shade, the plants can be incrementally introduced to direct sun.
Remember, increasing gradually is the key to success in the hardening off process. Each day, a grower should increase the amount of time the seedlings and/or young plants receive direct sunlight. Typically, young cannabis plants should be acclimated to direct sunlight in about a week.
If there is a strong wind present when a gardener is hardening off his or her cannabis plants, it is a good idea to create some sort of wind block. Even with a wind block, the plants will still be able to acclimate to the ambient humidity and temperature. Cold frames or mini-hoop houses are valuable tools for the hardening off process and can offer additional wind protection for transitioning plants. When introduced gently, the wind outdoors will help build up the overall structural integrity of the newly established cannabis plants.
Temperature (Cold Nights)
Many gardeners start the hardening off process when the night temperatures are still too cold for seedlings or young cannabis plants. It may be necessary to bring them back inside each night until the nighttime temperature increases or the plants become acclimated to the colder temps. Cold frames, or other temporary structures offering cover, can also be used to protect the seedlings and/or young plants from the cooler overnight temperatures.
After the plants have hardened off, it’s time to transplant them into the prepared soil bed or outdoor potting container. Transplanting cannabis plants can be very stressful for young plants with tender roots so it is very important to be cautious and minimize any adverse effects.
If possible, avoid transplanting at times when the plant is experiencing other stresses. Plants experiencing a pest insect infestation, excessive heat or cold, drought, or nutrient deficiencies, or that have not been fully acclimated to the outdoor environment, will be affected more adversely. Transplanting causes stress. There is no way to avoid it completely, but by taking extra precautions it is possible to keep transplant stress to a minimum.
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Nutrition for Early Stages of Growth Outdoors
A well-balanced, living soil is the best way to provide long-term nutrition to outdoor cannabis plants. Supplying additional beneficial microorganisms to the soil prior to transplanting is a great way to increase the soil’s overall biological activity. In addition to beneficial microorganisms, there are some soil amendments that specifically affect the early stages of root development and plant growth.
Incorporating some or all of these ingredients in a living soil will help give young cannabis plants the boost they need to establish solid structural integrity and a healthy root mass; both of which create a strong foundation for prolific yields down the road.
Blood meal is a fast-releasing, rich source of nitrogen. It is a great additive for cannabis plants and other plant varieties requiring high amounts of nitrogen. Fish meal is another fast-releasing nitrogen source that also enhances the microbial life in the soil. Fish meal contains a significant amount of phosphorus, which helps trigger early root development.
Another phosphorus source capable of promoting strong root development is bone meal. Bone meal is also a great source of calcium. Fish bone meal has the same beneficial qualities as bone meal, except it is derived from fish and provides both phosphorus and calcium to developing plants.
For early-stage potassium, kelp meal and langbeinite are excellent choices. Kelp meal is a source of readily available potassium along with a variety of micronutrients and plant hormones. Kelp meal can also increase overall plant health and vigor. Langbeinite (sold under many different brand names) is a naturally occurring mineral that is water soluble. Langbeinite is a good source of potassium, sulfur, and magnesium in the early and late stages of growth.
Calcium is just as important to plant development as nitrogen, phosphorus, or potassium, and should be specifically supplied to young cannabis seedlings or plants. Oyster shell is an excellent organic source of calcium that will accelerate root development and, in turn, improve nutrient uptake. Oyster shell also works as a pH buffer, preventing the soil from becoming overly acidic. Dolomite lime is a rich source of calcium and magnesium, which is very important for all growth stages of the medical marijuana plant.
Dolomite lime is also a stellar pH buffer for any soil composition and, as with oyster shell, ensures the soil’s pH doesn’t turn too acidic.
Early Season Pests
Pest insects aren’t as common during the early growing season as they are in mid to late summer, but that doesn't mean a cannabis garden will be pest free. In the early weeks after planting, a seedling’s or plant’s most destructive enemies are slugs, snails, or cutworms. These critters usually inflict their damage during the night hours by cutting small plants down to just stalks, completely obliterating seedlings, and/or leaving a trail of eaten leaves on larger plants. To protect a cannabis garden from slugs, snails, and cutworms, growers can implement a variety of defenses against these nasty critters.
Diatomaceous earth can be sprinkled around the perimeter of the garden or around each individual plant to create a barrier of protection. Diatomaceous earth is a popular insect deterrent among organic growers and works on a variety of pests, including slugs, snails, and cutworms. The skeletal remains in diatomaceous earth act like tiny razor blades which lacerate the pests as they pass over.
Like diatomaceous earth, crushed eggshells act as jagged razor blades that cut open the slugs, snails, or cutworms as they crawl over and cause death by dehydration. Growers can place crushed eggshells around the perimeter of the garden or in each planting container.
Another great and inexpensive defense against snails is sand. Snails and slugs do not like to cross sand. As with diatomaceous earth and eggshells, a barrier of sand can be placed around the plants to deter any snails or slugs from entering the garden. The sand should be spread at least a quarter-inch high and fine-grade sand seems to work the best.
Once a cannabis plant is properly acclimated to its outdoor environment, it will be able to live up to its full potential. After transplanting, the plants will become established and early season pests, such as snails, slugs, and cutworms, will no longer pose much of a threat. In fact, once cannabis plants are established outdoors, they have a naturally heightened resistance to pests and pathogens. This, combined with the presence of natural predators, makes pest control in an outdoor cannabis garden relatively easy compared with indoors.
Cannabis plants that are properly hardened off, carefully transplanted, and supplied with the proper nutrition for the early growth stages and root development will form a healthy root mass and have strong structural integrity, which will be the foundation for enormous cannabis flowers. Patience and attention are required of a gardener in the early stages of the outdoor growing season.
However, if the time is taken to properly acclimate his or her plants, provide them with optimal nutrition, and prevent pests, the cannabis cultivator will be rewarded in spades come harvest time.