Seeds and Germination
Marijuana Grow Basics by Jorge Cervantes
A seed contains all the genetic characteristics of a plant. Seeds are the result of sexual propagation and contain genes from each parent, male and female. Some plants, known as hermaphrodites, bear both male and female flowers on the same plant. The genes within a seed dictate a plant’s size; disease and pest resistance; root, stem, leaf, and flower production; cannabinoid levels; and many other traits. The genetic makeup of a seed is the single most important factor dictating how well a pant will grow under artificial light or natural sunlight and the levels of cannabinoids it will produce.
Weak plants are the result of weak seeds and poor growing conditions. Strong, healthy parents and proper care yield strong seeds that germinate well. Strong seeds produce healthy plants and heavy harvests. Seeds stored too long will germinate slowly and have a high rate of failure. Vigorous seeds initiate growth within seven days or sooner. Seeds that take longer than a month to germinate could always be slow and produce less.
People grow seeds rather than clones because of “hybrid vigor”, a phenomenon that causes F1 seeds that are the product of two true-breeding parents to grow about 25 percent stronger and bigger.
Typically, a grower who acquires 5-15 quality seeds from a reputable seed company germinates them all at once. Once germinated, the seeds are carefully planted and grown to adulthood. Normally some of the seeds will be male, some will grow slowly, and two or three seeds will grow into strong “super” females. Of these super females, one will be more robust and potent. Select this super female to be the clone mother.
Mature seeds that are hard, beige t dark brown, and spotted or mottled have the highest germination rate. Soft, pale, or green seeds are usually immature and should be avoided. Immature seeds germinate poorly and often produce sickly plants. Fresh, dry, mature seeds less than a year old sprout quickly and grow robust plants.
Germinating and Planting Seeds
To germinate, seeds need moisture, warmth, and air (oxygen).
Soaking seeds in water allows moisture to penetrate the protective seed shell within minutes. Moisture continues to wick in to activate the dormant hormones. In 24-72 hours, hormones activate and send signals to produce a small white rootlet (radicle).
Moisture is critical now. There must be a constant stream of moisture to transport nutrients, hormones, and water in order to carry on life processes. For best results use distilled water. Letting germinated seeds suffer moisture stress now will stunt seedling growth.
Cannabis seeds grow best at 78F (25C). Low temperatures (below 70F [21C]) delay germination. High temperatures (above 90F [32C]) cause poor germination. Once germinated, move seedlings to a slightly growing area and increase light levels. Avoid high temperatures and ow light levels, which cause lanky growth.
Seeds need air to germinate. Moist, soggy growing mediums will cut off oxygen supplies and the seed will literally drown. Planting seeds to deeply also causes poor germination. Seedlings do not have enough stored energy to force through too much soil before sprouting. Plant seeds twice as dep as the width of the seed. For example, plant a 0.125-inch (0.3mm) seed 0.25-inch (6mm) deep.
Too much or too little light coupled with overwatering or underwatering are the main reasons for poor seedling growth. This sickly freak trifoliate seedling is the result of dodgy genetics as well.
Overwatering and underwatering are the biggest obstacles most growers face when germinating seeds and growing seedlings. Keep the soil uniformly moist, not waterlogged. Do not let the growing medium’s surface dry for long. Keep it evenly moist. Setting root cubes or planting flats on a grate allows good drainage. A shallow flat or planter with a heat pad underneath may require daily watering, while a deep, one-gallon pot will need watering every three days or more. A properly watered flat of rockwool cubes needs water every three t five days when sprouting seeds. When the surface is dry (0.25-inch deep) it is time to water. Remember, there are few roots to absorb the water early in life, and they are very delicate.
Seeds do not need any extra hormones to germinate. household water contains enough dissolved solids (food) to nourish seeds through their first few weeks of life. Supplemental nutrients often disrupt internal chemistry.
Get seeds from a grower who developed them
This is an excellent option because the grower usually knows the strain he is growing well and can tell you many details about growing it. Most such growers can also tell you about the qualities of the plant – taste, aroma, and high.
Find seeds in a bag of buds
Bag-seeds are okay because you will know more or less what the taste, aroma, and high of the final product will be like. However, you will not know the growth characteristics of the plant, and the plant will not be genetically stable. Often the seed will grow into a plant that has only some traits of the parents. it could also have intersex (hermaphrodite) tendencies.
Order seeds via mail or internet
Before you buy anything, send the seed company an email with some questions and see how long it takes them to respond. A good seed company will respond in one or two business days with god answers to your questions. If you do not get a response, do not order!
You may prefer to order from a company you can contact by telephone. Speak to a qualified representative who will provide good answers to your questions. Companies with an email address and website are usually okay to order from, but make sure they answer your emails promptly. Always call several companies and ask them specific questions about the strains they sell.
Packaging is important. Seeds are easily crushed, and packaging must protect them from damage. Many seed companies place seeds inside the channels of corrugated plastic. The corrugated plastic is then placed inside an envelope and mailed. The volume of first class mail is great, and all sorting is done mechanically. Letters under one ounce (28 grams) are not opened. occasionally the Postal service will find such a seed shipment. When they do, they send a letter to the recipient stating they have confiscated the seeds. No further action is taken.
Some seed merchants do not tell the truth about their seed stock. They sell you seeds that are not what they advertise them to be. other companies take your money and do not ship seeds. It is easy to overcome such problems with a little homework.
Purchase seeds personally at a shop
Seeds are available at shops in many countries. Stores in Canada, Holland, Italy, Spain, Switzerland, united Kingdom, and several Central European countries sell seeds publicly. You can walk right in and buy them. When you talk personally with a seed merchant, you get exact information and can ask as many questions as you want. Often the salesperson has personal stories about favorite strains.
Seed Quantities and Pricing
Seeds are generally sold in packages of 5, 10, and 15. Prices range from about $3 to $30 USD per seed. Often less expensive seeds are perfectly adequate for many growers’ needs and desires. More expensive seeds are usually more stable and extra care has been taken to produce them. Furthermore, expensive seeds are often winners of recent cannabis cups or are more difficult to produce. My preference is to purchase seeds that are in the middle price range. Unless feminized, always purchase packages of 10-15 seeds, because the odds are that 50 percent of the seeds will be female and the other half male. Of the desired female seeds, some will show more desirable characteristics than others.
Feminized seeds are becoming very popular worldwide. When grown in a stress-free environment, virtually all feminized seeds grow into female plants. They are more expensive than “normal” seeds. normal seeds generally yield a 50/50 mix of male and female plants. Male plants are weeded out and female seeds are harvested.
Check seeds to ensure none are crushed. If seeds came in a see-through bag, do not open it. Call or email the seller immediately to explain the problem. if one or a few are crushed, return all seeds for replacement.
If you are not going to plant the seeds immediately, remove them and keep them from the original package. Keep seeds dry or they might start to germinate. Place them in a small dark vial or film canister with a dry packet of silicone, the kind you find in electronics packages. Label the crush-proof container before you place the seeds inside.
Store seeds in a cool, dark, dry place. Make sure to label containers! Some seeds will remain viable for five years or longer when stored properly. When 50 percent f the stored seeds do not germinate, the average storage life is over. But seeds a year old or older often take longer to sprout and have a ower rate of germination. Seeds store for a long time when humidity is less than 5 percent and temperature is 35-41F.
During seedling growth, the root system grows rapidly while green aboveground growth is slow. Water and heat are critical at this point of development. The new, fragile root system is very small and requires a small but constant supply of water and warmth. Too much water will drown roots, often leading to root rot and damping-off (rotting at the soil line). Lack of water will cause the developing root system to dry up. As the seedlings mature, some will grow faster, stronger, and appear healthier in general. A little heat now will help nurture small seedlings to a strong start. Other seeds will sprout slowly and be weak and leggy. Most growers cull sickly, weak plants during the third to fifth week of growth, and focus attention on the remaining strong survivors.
Speed root growth by keeping the soil 2-5F warmer than the ambient air temperature. ideally the ambient air temperature should be 75F and the growing medium temperature 77-80F. Use heating cables or mat to raise the temperature of the growing medium.
If you have just a few seedlings, you may want to save weak, slow-growing plants. Baby such small plants along and let them grow longer until they catch up with the others before moving them into the next stage of growth.
Seedlings need at least 16 hours of light daily. Many growers give seedlings 18-24 hours of light per day so they will grow as fast as possible. Seedlings that receive 16 hours of light and 8 hours of darkness tend t grow more female plants.
Seedlings require less intense light now and grow well under fluorescent tubes or compact fluorescent lamps (CFLs) for the first two to three weeks. Keep fluorescent lamps two to six inches above seedlings and CFLs 12-18 inches above foliage.
Metal halide or HP sodium HID lights can be used to grow seedlings. Growers prefer metal halides because the color spectrum of HP sodium lamps tends to make seedlings stretch between branch internodes. Keep HIDs three to four feet (90-120cm) above seedlings for best growth.
The seedling stage is over when rapid foliage growth starts. Rapid growth above ground is the beginning of the vegetative growth stage. Plants need more room to grow; transplanting into a larger container hastens development.
If you are growing a few seedlings, they are easier to maintain in bigger containers. Carefully remove the seedling in the moist rockwool block from the seedling container. Place the rockwool cube in a premade hole in the container of potting soil or soilless mix. Add more soil to cover the rockwool cube. Rockwool, Oasis, peat pots, etc. hold more water than most soils and soilless mixes. It is very important to cover them when transplanting. if the cube is left uncovered, roots tend to stay in the root cube and not grow into the soil.