Once the threat of frost has subsided, it’s time to get your outdoor or greenhouse garden started. But the real work begins earlier as you plan and prepare for the growing season to come. Prior to planting, get the information and equipment you’ll need to succeed.
Selecting and Ordering Seeds
If you plan to grow from seeds, you must select and procure them with enough time to get them started. Take a look at some reputable seed breeders’ websites or catalogs to get an idea of your options.
If you’re in a place with a reduced growing season, you’ll want an indica-dominant strain with a shorter flowering time. If you have a longer season or can extend it with a heated greenhouse, you can grow sativa-dominant strains that may not finish until November or later.
Find a seed company that’s been around for a while and trusted in the community, preferably one with plenty of favorable reviews online. Never have seeds shipped to the location at which you plan to grow.
The key to harvesting big plants in the fall is to start them indoors well before you plan to place them outside or into a greenhouse. This requires having a grow space under lights that are set for the vegetative stage: 18 to 20 hours of light per day. This space should be kept warm (70°F to 75°F), humid (relative humidity near 50%) and clean.
The largest outdoor plants—the ones that are weighed in pounds, not ounces—get their start indoors as early as December. They grow in their vegetative stage for months until they’re placed outdoors after the threat of frost has subsided. Then they continue to vegetate throughout the spring and summer before they flower in the fall.
Preparing Grow Beds or Containers
This is the time to loosen any compacted soil and to add compost and any amendments that may take a long time to break down. Outdoor grow holes can be improved over time by employing the technique of sheet composting. This means adding your cured compost on top of the existing soil and letting the worms do the aerating for you.
Tilling the soil harms the mycelial strands that work in concert with your plants’ roots. Instead of digging up the soil every year, you can allow this symbiotic relationship between roots and fungus to improve the quality of the soil and your plants’ ability to fight off diseases and pests. In this way, the beneficial bacteria and microbes create a “living soil” that gets better every year.
Germination can be accomplished in a number of ways. Some growers swear by the moist-paper-towel method. Seeds are placed between wet paper towels until they pop open, revealing the emerging taproot. Then the seeds are gently placed, root side down, into their medium.
The easiest way to start seeds is to plant them directly into the moist growing medium of your choice. Poke a hole a quarter- to a half-inch deep in your soil mix (or rockwool cube, coco peat, etc.) and drop in the seed. Fill in the hole with medium and keep it moist. Covering the container with plastic wrap will maintain humidity, and you should make sure it doesn’t dry out.
As soon as you see a tiny green shoot emerging, get the seedling under a grow light. A fluorescent, LED or high-intensity discharge (HID) light will all work for this, but you must keep the light at the proper height to prevent the plant from stretching and also to avoid burning the tender young shoots. If you choose to go with an HID, metal halide (MH) is better at this stage than a high-pressure sodium (HPS) light.
The Vegetative Stage
Cannabis grows in two stages, vegetative and flowering. During the vegetative stage, the plant grows shoots that turn into branches. Once a plant begins flowering, it stops growing branches and begins to form buds.
Indoors, the flowering stage can be triggered by cutting back the light cycle from 18 to 20 hours of light per day to 12 hours of light and 12 hours of uninterrupted darkness. Outdoors, this process begins to happen naturally as summer wanes and the days grow shorter.
Vegetative time can be shortened or lengthened artificially by using light-deprivation or light-supplementation techniques. Some greenhouse growers employ dark sheeting to reduce the amount of light and flower their plants sooner. In this way, they harvest earlier and avoid rippers, cops, and the bad fall weather that can ruin crops with mold and rot. Others use lights to extend their vegetative season in order to grow bigger plants.
During the vegetative stage, plants need nutrients that are high in nitrogen. On the NPK rating scale listed on plant foods, the nitrogen (N) ratio comes first, followed by phosphorus (P) and potassium (K). During the vegetative stage, use fertilizers with a high number for nitrogen (i.e., 5-1-1). Healthy green leaves and robust new growth are a sign that nitrogen levels are good, but yellowing leaves point to a deficiency (or possibly a pH imbalance). Burnt leaf tips indicate an overabundance of nutrients, so flush your plants with lots of plain water if you see leaf tips start to get crispy.
It’s important to note that the size of your grow hole or container is directly proportional to the size of your finished plant. “The bigger the root, the bigger the fruit!” as our friend Chris Bliss likes to say. You can’t grow massive plants in 1- or 2-gallon containers, and the smallest I would recommend outdoors would be a 5-gallon bucket. It’s hard to go overboard with the size of your container. Smart Pots (smartpots.com) makes a Big Bag Bed that holds 100 gallons!
The vegetative stage is the best time to foliar-feed your plants. Spraying your plants with water or a mild nutrient solution (such as liquid kelp or aerated compost tea) provides nutrients while also cleaning the leaves of any accumulated dust particles that can inhibit their ability to take in the maximum amount of light.
Foliar feeding is best done in the morning, before the sun is at its highest point, to avoid burning leaves. In the middle of the daytime, hot sun and bright light can force the leaves’ stomata to close up. Avoid spraying close to nighttime or the start of the dark cycle, as the liquid won’t have time to be absorbed and thus will linger on the leaves, creating the perfect place for mold and powdery mildew to develop.
Be sure to spray the mist onto both the tops and the undersides of leaves for full absorption and the greatest benefit. Never foliar-feed your plants indoors without first protecting your light from the moisture, and remember to stop foliar feeding about two weeks into flowering to avoid issues with mold, mildew and bud rot.
The vegetative stage is the ideal time for pruning and training in order to achieve more branches, bigger plants and a much heavier harvest. Once a plant has three or more nodes, you can begin the pruning process. It can be as simple as trimming the tops off growing shoots in order to increase the amount of future branches, but there are several different ways to prune selectively.
Some growers train branches by weighing or tying them down using the low-stress training (LST) technique. This increases the canopy surface area that the light can reach and turns secondary and other branches into main tops. Bushier plants produce much more pot than Christmas-tree-style plants with one main cola and the typical triangular profile.
A sinker like those used in fishing works great to weigh down a main branch without having to cut it. Once the main branch sags below the lower branches, a chemical signal is sent telling these branches that they’re no longer subordinate to a main top, allowing them to each become a dominant branch, thus significantly increasing your yield.
Smart growers introduce a trellising system during the vegetative stage in order to spread their growing branches wide. There are many different types of trellising, from chicken wire to strings or metal bars, but what they all share in common is spreading the canopy to create a more level surface area. Branches tucked underneath a horizontal trellis will produce many more bud sites than branches growing upward, so be sure to use some kind of trellis to get the most out of each plant.
As the growing shoots approach the trellis, bend them to fill the empty holes in the canopy. When they start the flowering process, leave them alone until it’s time to harvest. Take care when removing the branches from the trellis not to damage the delicate trichome glands on the string or wire.
You’ve done the work to give your plants a great start and strong vegetative growth. Once you see flowers begin to form, change your nutrient regimen to a plant food high in P and K (phosphorus and potassium). These macro-nutes contain the building blocks for stacking buds coated with essential-oil-filled glandular trichomes. Soon you’ll be enjoying the fruits of your labors, and you’ll be happy with the work you did earlier in the spring to ensure a successful harvest in the fall.