Chapter 13: Growing Outdoors: Soil, Fertilizers, and Water
Growing cannabis can be a very rewarding and fun experience, but it comes with its own challenges and takes some time and money. For the first-time grower without a lot of resources, growing indoors is likely too costly. The great news is that even the smallest outdoor cannabis garden can provide you with lots of great marijuana without the big expense of creating an indoor garden. All you need is a sunny spot, a rooftop, balcony, or terrace, and you can grow cannabis successfully.
Benefits for Outdoor Growing
There are many benefits to growing cannabis outdoors, but the most common reasons are:
Think About Your Climate
The first thing you need to do before you start growing cannabis outside is to think about the clime of your area. Cannabis adapts fairly well to different conditions, but it can easily be harmed by extremes. When temperatures stay above 86 degrees, it can cause the plants to stop growing, but if temperatures stay under 55, it can damage them and stunt their growth, and possibly kill them.
High winds and a lot of ran can end up causing physical damage to your crops, which will lower your yields. Too much moisture can end up causing powdery mildew and mold, especially during the plant's flowering stage.
Besides weather patterns, you need to have a good understanding of the day length and how it changes through the season. Here’s an example, places at 32° N latitude, such as Savannah, have 14 hours of light on the longest day of the year. Places at 47° N, such as Seattle, have 16 hours of daylight on the longest day of the year.
Having a good understanding of the amount of light you are having during the year is important for making your plants transition from their growing period to their flowering period. If you have experience in growing vegetables, those skills will typically translate easily to growing cannabis.
Choosing a Growing Space
Choosing a space to grow your plants is one of the most important decisions you are going to have to make, especially deciding between planting in-ground or in containers.
You need to make sure that your cannabis plants get as much light as they can get, especially during midday because this is the best quality of light. As fall gets closer, your plants aren’t going to get as much sun, and this is what will help to move the plants into their flowering phase. Some wind is great for the plants, especially if live somewhere hot. If you live in a place that has a lot of high winds, you should think about planting it close to a windbreak of some kind, such as large shrubbery, wall, or fence.
Finally, you will want to make sure that you have some security and privacy. A lot of people want to conceal their cannabis garden from possible thieves and nosey neighbors. Large shrubs, trees, or tall fences are the best way to do this unless you live in a secluded space. Legal states also require that you keep your cannabis plants concealed from the street.
Some people will grow in containers and have them placed on balconies or even on their roof to help shield their view. You can place a heavy-gauge wire cage around them to keep animals and thieves out. No matter what you choose, think about the size you would like your end plants to be. When cannabis is grown outside, it can get to 12 feet in height, or more, depending on what you allow it to do.
Pick Genetics
The success of your plants is going to greatly depend on the strain you choose because you want one that works for your location and climate. If cannabis is grown a lot where you live, then the odds are in your favor that there are a lot of strains that will grow well there, and some strains could have easily been bred just for your area.
Plants that you grow from seed are more hearty as a young plant than those grown from clones. Seeds can be planted directly in your garden during early spring, even if it is still on the cool side. The biggest issue is there isn’t a guarantee of what type of plant you are going to get. If you don’t get feminized seeds, you could have male and female plants, which means you are going to have to sex them out to remove the males.
Even if all of your plants are female, each may end up having a different phenotype. To make sure that you have the best version, you need to make sure that you choose its best phenotype, which can end up taking a while. Most beginners will start out using feminized seeds.
Depending on where you live, you could buy a seedling or clone from a dispensary. There are a lot of growers that choose to avoid these options because they don’t grow up to be as sturdy as those that are grown from seeds. You could also use auto-flowering seeds. They will start the bloom as soon as they reach maturity no matter the light they are exposed to. You could have a quick-growing crop, or have several harvests during a year using auto-flowering seeds.
The problem with auto-flowering plants is that they are sometimes less potent.
Get Some Soil
Picking out soil for your outside grown plants works a lot like picking out soil for the plants that are grown indoors. The plants need the same type of soil, no matter whether they are grown inside or outside. The only difference is if you choose to grow them in the ground.
If the soil where you live is made up of a lot of clay, it won’t drain well and won’t hold oxygen. This means you are going to have to amend it a lot. Around a month before you plan on planting your cannabis, dig into the soil where you are going to plant them and add in worm castings, manure, compost, and other decomposed matter. This will provide it more drainage and aeration and will provide your plants with nutrients.
If the soil is sandy, it may be easy to work with and drains well, but it warms up quickly and does not hold nutrients, especially if it rains a lot. You can do the same thing again, but this time you should add in coco coir, peat moss, or compost that will help bind the soil. Adding mulch on top of the soil will help your plants hold onto water and to keep the roots from getting hot. The ideal growing soil is loamy soil. It holds onto nutrients, moisture, and oxygen, and it also drains well. You won’t need to amend loamy soil.
Fertilize
We already know that cannabis has to have micro- and macronutrients, mainly phosphorus, potassium, and nitrogen. When it comes to outdoor plants, how you feed them will depend on the soil you use.
If you understand them, and how they work, then you can use commercial fertilizers. The first-time growing will likely want to avoid these, especially long-release granular fertilizers.
You can buy nutrients solutions that are made specifically for marijuana from a grow shop, but they tend to be expensive and can end up damaging your soil’s bacteria. They tend to be made up of synthetic mineral salts, and they are meant to be used for indoor growing operations.
Organic fertilization will use the natural microbial life of your soil and will help to minimize any harmful runoff. There are lots of different types of organic and natural fertilizers that you can buy at home and garden stores, such as kelp meal, bat guano, fish meal, bone meal, and blood meal.
Begin with fertilizers that are readily available and inexpensive. Some will end up releasing nutrients quickly, and your plants will easily use them, while others may end up taking months or weeks to release their usable nutrients. If you do this right, you can combine some products together along with your amendments to your soil to make sure that your plants receive the nutrients they need.
Again, testing soil can help this process so that you know exactly what you need to add to your dirt and how much fertilizer you are going to need to use. If you aren’t quite sure how much you should use, be a bit conservative with it as you always have the option to top dress if they start to look like they are deficient in nutrients.
Pick Containers
If you find that you don’t have great soil, you may decide that planting them in containers is the best option. If there isn’t a good place to put your plants straight into the ground, you can use containers and set them wherever you have a good, sunlit area. If you need to, you can also move them throughout the day so that they can be protected from the wind or heat and take advantage of the sun at all times.
When you grow in planters, you are able to use store-bought cannabis fertilizers that you would use if you were growing indoors since you are using premixed soil. This will help to get rid of a lot of the guesswork when it comes to fertilizing
However, plants that you grow in barrels, pots, or buckets will end up being smaller than the ones that get grown in the ground because the container will restrict their root growth. Basically, the size of your pot will help to determine the size your plant will become, although you can grow large plants even if they are kept in smaller containers if you use the right technique.
In general, a five-gallon pot is a great option if you want a medium to small outdoor plant, and a ten-gallon pot or bigger is best for a large plant. Regardless of its size, you are going to want to protect the roots of your plant from getting too hot from the warm weather because pots are able to conduct heat from the sunlight. This can end up limiting the plant’s growth, so you should shade them the best you can when the sun is at its highest.
Water
While outdoor-grown cannabis plants have the benefit of using the rain and groundwater, you will likely still need to water your plants frequently, especially during the hottest part of the year. There are some cannabis plants that are able to consume ten gallons of water a day when the weather is the hottest.
Growers in areas that are arid and hot will sometimes dig down and add rocks or clay below their plants to help slow down the water drainage, or they will plant them in shallow depressions that will help the water to runoff and move towards other plants. To improve water retention, you can also add in water-absorbing polymer crystals. Make sure you water deeply first thing in the morning to ensure they have the water they need during the day.
If you live somewhere where it rains a lot, you may have to take a few precautionary steps to improve the drainage as cannabis roots can develop fungal diseases if they become waterlogged. Some of these techniques include:
Plants grown in windy or hot areas will have to be water more often since winds and high temperatures will force plants to transpire faster. Remember, over-watering is a very common mistake. Water deeply, and then once the top two inches become dry, you can water again. Getting a moisture meter is a good idea.