Growing

Vegetative Stage

So if you started with the cloning section, technically you should end up here next.  I’m going to go into a lot of things about growing the crop all the way through flower in certain areas of this section, only because it’s stuff you need to think of before you begin the growth phase even.

Germination

If you ignored my plea to get a clone and want to plant your dumb seeds, germination is the process by which a plant grows from a seed. Like plants, a seed also needs light energy, moisture, oxygen, and the right temperature to undergo germination. To keep seeds healthy and viable for germination, they must be kept at the right conditions. Ideal storage conditions for seeds are low humidity (25%-35% relative humidity) and the temperature ranging from 40-50˚ F.

How to test if your seed is still viable:

No matter how perfect your storage condition is, it is important that you still test their viability if you didn’t use them in their first growing season. To test a seeds viability, first place a any number of seeds between 2 rolled and wet paper towels, place them in a sealable plastic bag. Store them at a temperature between 70 -75 ˚F and keep them moist. If the number of seeds that germinate is 0%, then the seeds are no longer viable.  Whatever percentage success rate you get, do the math to figure how many seeds you need to plant in each hole to be sure at least one sprouts there…

Generally seeds will start to germinate with warm and moist environments. Because of this, choosing the media to sow your seeds is very important. The ideal media has good drainage, fine texture, low soluble salt level, and is pathogen free. For optimal germination in most seeds, the soil should be between 75 -78 ˚F.  Temps lower than 75 ˚F or higher than 78 ˚F will result in slow or possibly no germination.

Watering your seeds should be uniform and done regularly. Intervals should be too long to prevent your soil from drying out between watering. The water you use should also be free of particles and PH controlled to somewhere between 5.5 – 6.2.

After you seeds have germinated. It’s time to transplant them. Be careful as you may damage your roots during transplantation. You can transfer seedlings into pots after they have grown their first set of leaves. If you are transplanting from larger set ups, then its best to wait for the plants to grow enough roots to fill their current pot. Timing is important. If you do it too early then you may end up damaging the “root ball” and your plant will either die or have low production when the root zone is damaged in the growing medium. If you transplant too early then the plant will have a lot of problems such as stunted growth, stem elongation, vulnerability to disease, and more. This will result in a low yield.

Indoors or Outside?

I’m certain amateur outdoor cannabis growing is generally illegal unless you have a greenhouse with a lock and framed construction, or you are growing hemp with a THC level of less than 0.3%.

Outdoor Garden Location

Scan your outdoor area for the idea location for your garden. Take note of the sun and wind patterns in that location. The location should have at least 5 hours of direct sun, but at least 8 hours is ideal.

Wind can damage and dry out your crop, especially when combined with heavy rain(or hail like we get in Colorado). Make sure that there is enough shelter from the wind such as buildings, fence, or any structure that can provide cover.

Also consider that location of your garden to have easy access of water as you will need a lot of water to maintain your garden.

And maybe try not to let the neighbors see it…

Soil Condition

            Soil quality is also very important in any plants growth. In Denver, we have high levels of clay in our soil that doesn’t allow good drainage or nutrition.  So I always say to prepare your soil before you start planting to have healthy growth. I don’t care how good your dirt is wherever you are, it can always be better.  Clear the area of any weeds, rocks, sticks, and any trash. Rake the surface to smooth it out. Till your garden to soften the soil.

Organic matter is vital for the growth of your plants. If the soil does not have enough nutrients then you will have to add more organic matter using compost or manure. Compost will improve texture, fertility, and drainage of your soil.

Local colleges and universities will often give you a soil analysis either free or inexpensively.

Raised Beds

Raised bed gardening mostly used in rocky regions where soils are rocky and alkaline soils which causes the growing season to be shorter. With a raised bed, you can have your own soil condition instead of working with subpar growing soil which will take a lot of effort and time. Raised bed allows easy access and reduce soil compaction.

Soil compaction reduces total pore space of a soil. More importantly it significantly reduces the amount of large pore space, restricting air and water movement into and through the soil. Low soil oxygen levels caused by soil compaction are the primary factor limiting plant growth in the landscape setting…. Soil compaction can change a block or aggregate structure (with good infiltration and drainage) into a massive structure (with poor infiltration and drainage).

Raised bed also reduces foot traffic which is one of the causes of soil compaction. This also provide a barrier from small pest such as slugs, snails and insects. Boxed raised beds are good at preventing your soil from washing away during heavy rain. Having a raised working area also helps with people who have back issue as they no longer need to bend too much.

Raised beds are easy to construct. Construction lumber is ideal and can be treated to last longer. Simply create a box with the construction lumber using an ideal width of 4 ft. the length of the box can be of your choice. The height of the box can be around 8 to 12 inches. Fill the box with your desired soil mixture which we’ll go into later.

Raised beds can be without the box. Soils are simply formed in a mound. Walkways are then dug between mounds. They are cheaper to make but will require more maintenance as the soil can be washed away by rain.

Container Gardening

Container gardening is putting the crops or plants in containers, usually individual containers, instead of planting them in the open field. This is primarily used in Indoor gardens.

Advantages of growing plants in containers:

  • You have more control in your growing soil as they are quarantined in one container. Use of potting soil is more efficient. Most of the time potting mix is only used such as Coco Coir, Roots Organics, ProMix, Ocean Forest, etc.
  • Plants are portable. The containers can easily be moved without damaging the plant. This is very helpful for people who want to constantly change the arrangement of the ornamental plants. You can easily remove a plant after its flowering phase and replace it with another plant that is still in its flowering phase.
  • Allows you to grow plants on any part of your house as long as the plant gets adequate light. This is perfect for ornamental plants that add beauty to your home.
  • Allows you to grow plants together that would normally be in competition if planted traditionally. For example some plants need different soil conditions and will not grow healthy together.
  • Due to the containers being isolated, it prevents weed growth and will require less maintenance.
  • Does not require heavy equipment to maintain the soil quality.
  • It controls the growth of plants that would normally grow too and invade the space of other plants.
  • Less prone to insects. As they are normally separated from the wild growth, they are less exposed to pest.
  • There are decorative pots that help enhance the beauty of your plants.
  • Can be placed on elevated spaces so you will no longer need to bend over for regular maintenance. This is especially helpful for people with back problems.
  • Reduce the climate impact as you can easily transfer the plant to a shelter during harmful climates.

Growing Media

Media is one of the most important part in plant growth so we have to know the best media to use for our plants. There are a lot of things to consider when choosing a media. When you go to your local garden store and check out the soils available. You might get confused of all the things that companies put in garden soil. Don’t worry! We will help you understand the components in common potting soils and which are best for you.

Soilless Growing Media

Technically, the best potting soils sold in the market are actually soilless mixes. This means that they do not contain the natural components of soil such as sand, silt, or clay. Soilless media are great as they give you control over the amount of nutrients, pH level, and other properties necessary for plant growth.

There are 2 common bases of soilless mixes:

Coco coir based mix – this is the most commonly used potting mix. Made from coconut fibers which makes it all natural. It is generally ground coconut fibers and may also come in variety. The air and water ratio of coco coir is perfect which allows you to use more water. Coco coir has a high Cation-Exchange Capacity (CEC) that allows easier access to nutrients that will increase the growth of your plants. The downside to this is that Coco coir lacks Calcium and Magnesium so you will need Cal-Mag supplements.

Peat based mid – Peat is partially decayed and dried sphagnum moss. It is rich in organic matter and is able to retain more moisture than coco coir based mix. This means that you need to be more controlled in watering. Peat has a pH level between 3-5pH so you may need to balance it out by using lime.

Add-ons

These add-ons are what defines that final properties of the mix which helps maximize your crop:

  • Perlite: increases drainage and aeration
  • Dolomite lime: buffers pH, provides calcium and magnesium
  • Worm castings: natural source of nitrogen, enhances beneficial microbe population
  • Mycorrhizae: symbiotic growth on and around roots, increases water and nutrient uptake
  • Azomite: buffers pH, slow release of micronutrients
  • Oyster shell: buffers pH, provides calcium
  • Yucca extract: natural wetting agent, increases uniform water absorption of planting mix
  • Dried kelp: source of potassium and natural plant hormones
  • Alfalfa meal: organic source of balanced fertilizer, amino acids and triacontanol
  • Feather meal: source of organic slow release nitrogen
  • Fishbone meal: organic source of phosphorus and calcium

Planting

            After you have finished preparing everything it is time to plant. Plant in rows from north to south. Allow enough space between each crop, 2-3 feet is ideal for outdoors.

Greenhouses

Having a greenhouse is the easiest way to have a more controlled environment and will help extend growing seasons. Greenhouse is really helpful for people who want to have their own supply of fresh, home grown vegetables. It gives you shelter from harmful weather and a great place to stock warm compost piles.

Greenhouse Structures

            Most greenhouse structures are made from plastic sheeting with metal frames. There are greenhouse kits available from your local hardware or garden supply stores. The kits come in different styles and sizes. It is recommended to reinforce the frames with galvanized steel pipes to protect against snow or heavy wind. The bigger your greenhouse the better it will be able to buffer the temperature and humidity. Bigger space means you will have more space to work with.

Air ventilation is important. Some greenhouse are designed to easily roll the plastic sheets to the sides. There are some that will require ventilation fans. Always remember not to overcrowd your greenhouses. A proper greenhouse should have enough air flow, heat dispersal, and removal of excess humidity.

Benefits of Greenhouse

            Greenhouse and indoor gardens allows you to have extended growing seasons that may be whole year round. The methods and equipment we have today allows home gardeners to grow herbs, fruits and vegetables indoors. Although the investment to be successful in this is not anyone can afford. It takes the love of growing your own to overcome the work and cost to maintain indoor and greenhouse gardens. But hard work will always be rewarded. After some time, you will enjoy the fruits of your labor and see the returns of the time and money you have invested.

With the new technologies available, indoors gardening have begun to match the quality of outdoor gardens. The only downside to this is the extra maintenance cost that will reduce your total return.

Nutrients

The requirements of vegetative and flower growth cycles are different. Vegetative growth requires more nitrogen and magnesium. This is because nitrogen and magnesium are need for chlorophyll production which is used for vegetative growth. Calcium is also needed to provide structural stem growth and support. These 3 elements are needed in high quantities during vegetative growth. At this period, excess sugar is produced that will be used during the flowering phase. During the veg stage your plants will direct all their energy to growing larger. The healthier the plant is during growth phase, the better the results will be during flowering.   The plants are building up energy and weight to be used during flowering, so I actually spend much more time with my growing plants than my flowering ones.  Just don’t let them get too tall before you switch them to flower because they can double in height during flowering.

Plants get their nutrients needed for growth from the soil, but sometimes there is not enough for them to grow fast and large. Nutrient deficiency also makes the plants prone to disease. Fortunately we can avoid this by using plant food. Most plant foods come in different varieties: liquid, granules, pellets, tablets, and stakes. All have different pros and cons.

Here is an easy guide to choosing the best plant food you need.

Granular – This is the least expensive food. Usually granular fertilizers need to be applied every month or two. They are mostly used for lawn and general gardening.

Application: Sprinkle over soil in flower beds, then scratch with rakes; or you can bury it with the plant. Mix with will tilled soil before planting, or can be applied along rows and top of the soil. Soak the soil after every application.

Liquid – Usually comes in concentrates and needs to be diluted in water. They may also come in dry products that will dissolve in water. Easily taken up through the leaves and roots. Effective in small container plants.

Application: Follow label instructions for dilution to avoid plant damage. Apply close to roots or injected into the soil every week or two.

Controlled release – They come in beadlike granules that release nutrients into the soil every several months; longevity depends on formulation. The good thing about controlled release is that the interval between applications last for more than a few months. Can be used in a broad range of plants, usually not marijuana.

Application: Dig into the soil during planting time or dig in the surface near the plant.

Organic – Natural based products usually sold in boxes. Common organic fertilizers are bat guano and fish pellets that contain all three primary nutrients. Here is a list of organic fertilizers and the nutrients you get:

  • Blood meal, cottonseed meal, and Poultry waste – Nitrogen
  • Bone meal– Phosphorus
  • Kelp or granite meal – potassium

Application: scatter above roots, dig into the soil, and water after application.

NUTRIENTS

Plants needs various elements to grow. Carbon, Hydrogen and Oxygen that comes from air and water are just some. Other elements are taken from the soil through the plants roots. The plants roots play an important role in gathering the important macro and micro nutrients essential for plant growth.

Macronutrients

            These are the nutrients which the plant consumes in large amounts. The main macronutrients are Nitrogen, Phosphorous, and Potassium. The other macronutrients are Calcium, Magnesium, and Sulfur.

Micronutrients

            These are the nutrients which the plants consumes are small amount. Micronutrients includes: Boron, Copper, Chlorine, Manganese, Molybdenum, Iron, and Zinc. Even though they are used in small amounts they still play an important role in the growth of the plant. If one of these micronutrients is missing will negatively affect the growth and reproduction of the plant. Excess of any of these micronutrients is also harmful to the plant as they can become toxic. It is important that you know the right amount of each micronutrient the plant needs as it is sensitive.

Nutrient Uptake

            Nutrient uptake is done through cation exchange. The root hairs release hydrogen ions into the soil through proton pumps. The hydrogen ions transfer cations attached to negatively charge soil particles. This will allow the root to uptake cation from the soil.

            Cation Exchange Capacity (CEC) is the ability of the soil to hold onto cation nutrients.

 Nutrient Mobility

            The nutrients in the form of ions have different mobility within the plant. When a nutrient is scarce, the first signs of nutrient deficiency is dependent on the mobility of the nutrient. A mobile nutrient deficiency will show symptoms in the older leaves because the nutrients is able to go to the new growth where it is needed most. While immobile nutrient deficiency will show signs in the new growth because it is stuck in the older growth.

Macronutrients

Macronutrients are the nutrients that the plant consumes in large quantities.  The following are Macronutrients and their roles:

Nitrogen – is the main contributor in plant growth. Nitrogen is a component of amino acids which is the building block for proteins. The proteins are the ones that regulate the metabolic process. Nitrogen also plays an important role in photosynthesis and chlorophyll molecule (C55H72MGN4O2).

You can see if the plant has sufficient supply of Nitrogen if the plant is dark green and has a healthy growth. If there is Nitrogen deficiency then you can see slow growth, chlorosis(Yellowing), and fibrous stiff stems.

Ammonium (NH4+) and Nitrate (NO3) are the main source of Nitrogen for plants.

Phosphorus is responsible for the growth and development of the roots, flower, and fruit. It is also has a role in the cellular process, energy transfer and as a building block of the cell walls and DNA.

A sufficient supply of Phosphorus will increase plant and root growth, strong stems, and early crop maturation. Phosphorus deficiency will reduce plant growth, delayed maturation, small fruit set, and purple colorings on the old leaves. Phosphorus requirements is increased during the flowering phase.

Potassium – is the only Macronutrient that is not a factor in structural growth. Potassium acts as a regulating element. It controls the flow of water and carbon dioxide in and out of the plant.

When potassium is insufficient, the plant will often wilt. There are also signs of reduced plant health and weak stems.

Calcium – helps build strong cell walls and is important for structural stem and plant support. Excess potassium can prevent the uptake of sufficient calcium which will cause Calcium deficiency. Calcium deficiency in plants will result in malformation in growing roots, shoots, and leaves.

Magnesium – is important in photosynthesis as it is a component in chlorophyll molecule. Magnesium deficiency is characterized with reduced chlorophyll production, and interveinal chlorosis.

Sulfur – plays a role in structural components and metabolic processes within the plant cells. This is because sulfur is a component for amino acids used in both. Chlorosis on newer growth is a sign of sulfur deficiency, although it occurs rarely.

Micronutrients

Micronutrients are nutrients that plants use in small quantities.  The following are Micronutrients and their roles in the plants health:

Boron – affects flowering, pollen germination, fruit set, nitrogen metabolism, and hormone movement. Boron also plays a key role in transporting potassium across the cell membrane that regulates the leaf stomata. Boron deficiency is characterized by terminal bud necrosis, lateral branch growth, and lateral bud necrosis. Leaves will also thicken, curl, and become brittle.

Chlorine – is important in the function of the stomata as it is used to counter balance Potassium. Chlorine plays a role in photosynthesis as it is also responsible in providing electrons required to break bonds holding the water molecule together.

Signs of Chlorine deficiency can be found in younger leaves. The leaves will start will at the tips and turn bronze. Leaves may also show mottled cholorosis. You will also see stunted growth in the roots.

Copper – is a vital component in enzymes, chlorophyll production, a catalyst for respiration, and metabolism of proteins and carbohydrates. Terminal leaf bud necrosis, sluggish growth, chlorotic leaves, and new growth leaf necrosis are signs of Copper deficiency.

Iron – is involved in a lot of plan processes that the plants have developed ways that it will never be unavailable. Iron is a key component in enzymes and proteins; used in nitrogen fixation; a catalyst in chlorophyll synthesis; and a carrier of electrons. All of its uses makes Iron an important component in respiration and oxidation-reduction reactions.

Iron deficiency is present when there is interveinal chlorosis (green veins and yellow leaves) starting at the new leaves.

Manganese – is used during photosynthesis to free up oxygen. It also acts as a coenzyme that helps breakdown carbohydrates.

Interveinal chlorosis in new growth is a sign of Manganese deficiency. Afterwards the leaf will turn white and fall of. Manganese deficiency may occur if there is high pH in the soil.

Zinc – helps form auxins (main plant growth hormone), chloroplasts, carbohydrates, and proteins. Zinc also plays a part in oxidation-reduction reactions.

Zinc deficiency is maybe present when there is chlorosis in older leaves, lack of stem elongation and reduced growth. Zinc deficiency is often caused by pH above 7.5.

Nutrient Relationships

All plants need various nutrients for a fast and healthy growth. Although they differ in quantity that the plant will use, it does not mean that one is more important than the other. All nutrients must have a certain balance in the soil for the ideal growing condition. If a certain nutrient is in excess, it affects the uptake of other nutrients and thus affecting the limiting the growth of the plant. The Mulder chart demonstrates the relationship between the nutrients and how they affect the uptake of the other nutrients.

 

When a nutrient is in excess, it can negatively affect the uptake of some nutrients. This is called Antagonism. Excess of nutrients is usually due to the soil being naturally rich in the certain nutrient or the improper use of fertilizers.

Common Antagonism:

Potassium – excess potassium hinders the uptake of Manganese and Calcium. This results in poor yield and/or poor quality of the crops.

Calcium & Manganese – excess of both will also hinder the uptake of potassium. This also results in poor yield and/or poor quality.

Phosphorus – excess phosphorus hinders the uptake of Zinc and Iron. This will result in poor yield.

Nitrogen – excess nitrogen hinder Sulfur and Copper uptake. This results in poor yield. High nitrogen will also soften fruit.

Sulfur – Excess sulfur will cause selenium deficiency.

Molybdenum – Excess Molybdenum will cause Copper deficiency in the crops.

Stimulation

Some nutrients in excess will also cause the plant to increase its demand for certain nutrients. This is calledvstimulation.

Example of Stimulation:

As Nitrogen uptake is increased, the demand for magnesium is increased.

Excess potassium uptake will increase the plants demand for manganese.

We should always remember that the excess or deficiency of one nutrient will affect other nutrients and will ultimately affect the overall crop yield. Balance is the key to a fast and vigorous plant growth.

Leaf Chart

Hydroponics

Perhaps you are thinking since everybody says “hydro” all the time, maybe you should try it out first.  IT IS MUCH EASIER TO GROW IN SOIL, COCO, or PEAT MOSS.  But if you wanna give it a shot, I’ll give you a little intro lesson.

Hydroponics is a method of delivering nutrients to plants with the use of fertilizer mix or solutions, and water, without the use of growing soil. Hydroponics is usually used when people grow plants that are not adapted to the local climate. This is because Hydroponic systems create an environment that can be carefully controlled to provide an ideal growth condition. This allows farmers to grow high quality product anywhere in the world that would normally be impossible for traditional gardening.

Hydroponics allows the detailed control of the water temperature, nutrient, and pH levels.  This greatly reduces the risk of pest and disease problems and ultimately improves the overall crop yield. The delivery of the nutrients is constant in small amounts, allowing more nutrients readily available for the roots to uptake 24/7.

There are several types of Hydroponic systems. Generally they are categorized in a few ways.

Flood Drain System

Flood and drain hydropodonics is the method of delivering the nutrient solution to the plants via a pump, allowing the roots to uptake the nutrients they need.  This is called the Flood phase. After some time, the nutrient solution is discharged, and any nutrient solution that were not used are now dumped back into the reservoir.  The nutrient solution is drained and recaptured in the reservoir to be recirculated again for the Flood phase after some time. The down side to this is that constant monitoring of the nutrient solution is need to ensure the balance of nutrients. The plants take up different levels of each nutrient, and as the nutrient solution is constantly recirculated, some nutrients will build up and can cause more harm than good. The nutrient solution needs to be changed at least every two weeks or so to ensure the ideal balance of nutrients.  As the plants grow, the frequency of floods if also increased. They may take some time for beginners to know the frequency necessary for optimal growth.

General Hydroponics Flora Series Simple Drain To Waste Simple Feeding Chart

Flood and drain is famous for its simplicity, reliability, and low investment cost. This is also beneficial for experienced gardeners as they have the flexibility to adjust the number of floods per day and also the duration of the drains.

Benefits of Flood Drain system

  • Constant feeding at small amounts allows the plants to take up more nutrients and water. This results in faster growth and higher yields.
  • Roots are able to take in more oxygen. During the flood period, air is flushed out of the roots and fresh oxygen is taken in after drain periods. Oxygenated roots improves the health of the plant.
  • The system is flexible. Allows experienced growers to set their desired growing conditions. You can set different flood and drain frequency for different plant allowing optimal growth for each variety.
  • Prevents buildup of nutrient salts. Any nutrients not being used by the plants is drain back into the reservoir. This prevents excess nutrients that can have negative effects on the plant growth.

The downside to Hydroponic flood drain systems is that they are inefficient in the use of water and nutrient solutions. The plants can also be prone to root disease.

Recirculating System

In a recirculating hydroponic system, water solution is continuously captured into reservoirs and reused. The water solution contains nutrient solutions or fertilizers. Nutrient solutions or fertilizers are added when nutrients in the current solution have been depleted. The reservoirs is changed every 1 to 3 months depending on the condition of the water. This prevents unbalanced nutrients and nutrient build up that will negatively affect the growth of the plant.

Recirculating is useful for those who have a low supply of water as minimizes water loss compared to traditional agriculture. Majority of the lost water is due to evaporation and irrigation leakage. Water is a valuable resource that is finite, recirculating helps save this valuable resource.

Most hydroponic recirculating systems are simple and has a low investment cost. The important thing is to constantly check the nutrients and keep it balance, this can be hard for beginners.

There are different types of recirculating systems being used. Here are some examples of recirculating systems:

  • Nutrient Filter Technique – plants are arranged along a sloped irrigated channel. Nutrient solution is pump from the top and is allowed to flow down and drains into a reservoir. NFT does not have any media for rooting. The absence of media allows easy inspection of the roots for signs of disease, nutrient deficiency, etc. Prevents nutrient salt build up and allows uniform root zone pH and conductivity.
  • Aeroponics – this system does not also require media. The plants roots is freely suspended in a well-ventilated container. The nutrient solution is given via spray nozzles and high pressure pumps. This will create a mist or fog that is delivered 24 hours. The roots are exposed in an oxygen rich environment that promotes overall plant growth. Roots can easily be inspected and treated when needed. The downside is that pump needs to be well maintained otherwise pump failure will result in plant death in just a few hours.

Drain to Waste

Drain to waste – Drain to waste systems will deliver the nutrient solution to the plants via sprayers or drippers instead of flooding the tray container.  Whatever is not absorbed during watering by the growing medium and root zone runs off to waste.  The maintenance cost for drain to waste systems is high as there is a lot of water and fertilizer solution being wasted.  I know it sounds dumb but this is my favorite method.

 

Actual Growing…Finally

Vegetative growth and flowering have different ideal conditions. We will show you the difference in temperature and nutrients requirements between vegetation and bloom.

Light

Light quality is based on its wavelength or color. Vegetative growth is best with blue light which has lower wavelengths. Red light which has the longest wavelength is best for flowering.  That being said, 6000-6500K(Kelvin) is blue, 3000-4000K is red for bloom, completely opposite numbering based on the wavelengths.

Different plants have different light requirements and tolerance.  So it’s important for you to know the each of your plants requirements and limitations.

Always remember that when you are transferring your plant to a higher light intensity make sure that the change in light intensity is gradual. This will give time for your plant to adjust and protect itself from sunburn.

Light duration is the amount of time your plant is exposed to the light. When you have indoor plants, light duration should be 12 hours. The opposite of this, the time in darkness, is the photoperiod.  Having a photoperiod that is 14-12 hours is the only way plants’ flowering growth is triggered.

There are 3 types of plants based on their response to photoperiod:

  • Short-Day plants respond to long photoperiods (NOT CANNABIS)
  • Long-day plants respond to short photoperiods (CANNABIS)
  • Day neutral plants will undergo flowering growth despite the length of the photoperiod. (AUTOFLOWER CANNABIS)

Actual Lights

Ok, so you have a few options for lighting during the growth phase.  I prefer LED lights, but they can be pricey compared to other options.  If controlling air temperature with ventilation will be difficult in your veg room due to a lack of windows or exhaust vents from your growing area, you should probably use flourescent or the best option would be LED lighting.  These lights produce the most light with the smallest amount of heat and energy used.  High intensity Metal Halide lights would probably grow your plants the fastest, but also use the most energy and produce the most heat, so you’ll have to ventilate air in and out of the room to keep everything cool and healthy if you already have or plan to use HID lighting in veg.

Light is a fundamental need for plant growth both indoor and indoor garden. We must make sure that the plant gets enough light for optimal growth. The quality of light is based on its spectrum. Plants are sensitive to the light spectrum of 400 – 700 nanometers in wavelength, this is called photosynthetically active radiation (PAR). As we can see in the graph bellow, plants respond best with blue and red light. Plants are most sensitive around 630 nm. Red light gives the best condition for photosynthesis. But red light is not enough, without blue light the plant will not fully mature.  The ideal quality light is to have both blue and red spectrum. For indoor gardens, use a light that can provide a balance of red and blue.

The spectrum of light generally emitted from bulbs are have respective temperature range measured in Kelvin (K). Red bulbs are measured around 2000 K and blue bulbs are measured above 3200 K.

Plants that are not able to receive sufficient light will have a slow and spindly growth. The overall crop yield will be low. Too much light is also not good as this will dry up the plants and eventually they will wither, and become bleached as the chlorophyll will be damaged. It is best to have the amount of light at the upper range of the limit to have the ideal growth conditions. Aside from photosynthesis, there are also other plant processes that are triggered by light such as germination and flowering. The amount of light a plant receives is called photoperiod. Plants that flower yearly generally vegetate under long photoperiods, usually more than 18 hours of light per day. Flowering will then usually occur during shorter periods, 12 hours of light per day. Inconsistent photoperiods can cause stress to plants and will results longer flowering time and intersexual growth traits.

High intensity discharge

(HID) grow lights are the most commonly used light for both indoor and greenhouse gardening. They provide a high intensity and a wide coverage of the area. They have become the standard indoor gardening light because of the high yields they generate. The downside to HID is that they produce a lot of heat and consume more power.  HID lights consist of a light ballast, lamp reflector, and HID bulb.

Metal Halide (MH) Lights

MH lights emit the strongest blue light in the light spectrum. High quality MH lights can burn up to 6000 Kelvin that helps produce healthy, lush, green growth. MH light may require some maintenance after 6 to 10 months of use. Cheaper MH bulbs may appear white – green in color and is not as effective in producing optimal growth. Cheap MH bulbs also have lower life expectancy at 3 – 6 months.
1000 Watt Double Ended Metal Halide bulbs are the industry standard for commercial grows here in Colorado, and they can cover up up to a 6 by 6 foot area.

Plasma Lights

Plasma lights are relatively new with a low wattage consumption and high PAR output. Plasma lights are great for moist environments as they do not have any moving parts that can be prone to corrosion. Plasma lights have a very long life expectancy of 50,000 hours of usage due to the fact the it no longer uses electrodes or filaments. Plasma lights are able to provide sunlight spectrum which provides the best light to grow the highest quality product.

High Pressure Sodium (HPS) Lighting

HPS are considered as the standard light used in the industry that promotes flowering. These are not designed for vegetative growth, but will work fine in a pinch,  Hortilux have longer life expectancy than cheaper bulbs which can only last around 6 months, Hortilux can last up to 9-12 months. HPS lights can last up to 4000 hours of usage. Cheaper bulbs also have a limited spectrum unlike HPS that has a broad light spectrum that is able to provide red light as well as a good amount of blue light.

Fluorescent grow lights are cheaper than most of the lights used for plant growth. It also give of less heat and more energy efficient than HID lights. The only down side to it is it has low intensity and small range of the light spectrum.  T5 bulbs are the most common form of flourescent fixture in horticulture growing, and most commonly used for growth but not flowering. They produce a good amount of light with minimal heat, but the light intensity is weak and penetration into the canopy is low.  With these bulbs the benefit is their low price and low heat output.  A 4 foot 8 bulb unit is perfect for a 4 foot by 4 foot canopy, but will consume over 400 watts of energy, so you can see it is much less efficient than LED’s but far better than HID’s.

New Light Tech

The light technology we have now has greatly helped in improving the plant growth and over all crop yield for indoor and greenhouse gardens. The quality of plants that are grown in indoor gardens have been so greatly improved that it even exceeds that of outdoor gardens, especially for those geographies that have short growing seasons.

There are various types of lights that can be used in gardening and some standard lights that were used in the industry have been replaced by more energy efficient lights. The important factors in choosing the type of light you are going to use are price, life expectancy, intensity, and the light spectrum they provide.

Light Emitting Diodes (LED) grow lights have greatly improved over the years. More people have been using them for both personal and commercial gardens. Although they are relatively expensive, they provide a lot of benefits. They produce less heat and are more energy efficient than the HID lights. The LED also have a very long life expectancy of 5 to 7 years. The initial investment will slowly return through the energy and replacement you saved. LED lights can be confusing to purchase, many list wattage numbers that are not even close to what the unit actually uses.  This is because LED lights are so much more efficient than lights that use gas or filaments like flourescent and HID lights.  A 500 watt LED is equivalent to 1000 watts of high intensity light from a glass bulb.  A small LED will be listed around 300 watts of power, but it’s actually consuming only about 150, and is perfect for covering a 3 foot by 3 foot plant canopy.   If your growing area is larger than that, perhaps you should consider getting a larger unit, a model labeled as 1200 watts that is actually drawing 600 watts of powers will cover a 6 by 6 area well.   The main benefit to using LED lights is high efficiency and low temperatures. Downfalls are high initial investment cost, and small light footprint.

Double Ended (DE) Lights

Double Ended (DE) lights are an improvement of the original mogul socket HPS lights. DE lights have higher life expectancy than standard HPS and MH lights. DE lights are believed to have a 10,000 burning hours. They also have better photo-synthetically active radiation (PAR) value in the light they emit.

Double Ended (DE) grow lights have a very high range of light spectrum compared to most. They are more energy efficient than other lights. DE lights produce higher light intensity than single ended lights.

Ceramic Metal Halide(LEC Light Emitting Ceramic)

This is the newest bulb, and although it has Metal Halide in the name, don’t mistake these for veg bulbs.  Of course they work wonderfully for veg, but they are perfect for bloom also.  The standard wattage is 315, but the bulb puts out light similar to that of a 1000 watt light.  Various bulb colors are available from multiple manufacturers.  From my research, these lights are actually more efficient than LED’s.

Environment

If you are going to use MH lights, you probably will need a way to cool the room.  If the light(s) bring the room’s temperature above 80 degrees Fahrenheit, the plants won’t grow as well, and any prolonged period of time above 95 degrees will probably kill the plants.  If you have air conditioning, you can always use that, but it is far less efficient than just moving cooler air from outside into the room and pulling hot air out of the room.  Unless you live in a tropical climate, a set of fans and ducting should be sufficient to cool any room without AC.  Swamp coolers can be used in desert climates, but the high humidity they create can present issues for your plant’s long term health.

Temperature

Plant growth is affected by the day and nighttime temperatures as well as the difference between these temperatures. Controlling temperatures indoors is easy but outdoor garden a different story.

You have to consider your areas climate and what plants you can plant that will suit your climate. Identify it your crop is cool or warm season plant.

  • Warm season plants germinate at 50-90°F
  • Cool season plants germinate at 40-80°F

Generally higher temperatures means higher photosynthesis and respiration until it reaches the upper limit. If the temperature exceeds this limit then respiration is higher than photosynthesis. This means that your plant is consuming more sugar than it is making which will hinder the growth of your plant. The sweet factor of your crop will also be reduced.

Heating, Ventilating, and Air Conditioning Systems

What is HVAC?

Heating, Ventilating, and Air Conditioning systems provide heating/cooling for residential, commercial, and industrial buildings. It also provides fresh and clean air by filtering out airborne contaminants such as odors, volatile organic compounds, chemicals, and other pollutants. An effective HVAC will provide a controlled environment whole year round.

HVAC use for Indoor Gardening

Indoor gardening is useful if you want control over almost every aspect of your growing environment especially air temperature, CO2 levels, and air humidity. HVAC will allow you to easily control all three at the ideal levels. This maximizes the growth of your plants whole year.

With the help of HVAC, you can also minimize the pollutants, pest and any harmful elements that can reduce your crop yield.

Generally, temperatures during lights on phase is best kept at 75 – 85° F and a humidity of 50%.

Setting up your Garden HVAC

The lights in your indoor garden will generate heat. Generally for every 1000 watt light you will produce around 3500 to 4000 BTU. You will need to compensate with your cooling system to reduce the heat in your indoor garden. For example if you have 10x 1000 watt lights then you would need 35,000 to 40,000 BTU of cooling. So you would need more than 40,000 BTU of cooling so you can achieve the desired temperature.

Controlling the humidity if also important. Low humidity will dry out your plants. Using a humidifier will help you get the desired humidity which is 50%. To calculate the amount of humidification. Most plants usually require 1.3 liters of water per day. This is the amount of humidification per pant per day. So you will need 1.3 L of humidification per plant per day.

Air flow is also important. You have to make sure that the air cycle is done every 3 minutes. To prevent any pollutants going into your garden, you will need to put filter for all the fans.