Germination and Growth of Cannabis


Healthy seed grown as outlined will normally germinate in 3-5 days, and definitely well within a week. During that period the warmth combined with the moisture triggers the seeds vital functions to go into action, and the shoot emerges. It’s at this stage that the young plant is at it’s most vulnerable, and therefore it only makes sense that a lot of care should be taken not to disturb it now. The good saturation of the jiffies and their contents at the start means that no further watering will be required until the seedlings have emerged. If the surface of the mix is looking dry moisten with the mister bottle. If the bottoms start to dry out add a little water to the perlite. Once the plants are up there is less chance of rotting, and water can be applied more liberally.


Vegetative growth is the second stage in the life of a plant after it completes germination and begins photosynthesis. During this stage a plant will photosynthesise as much as possible to grow as large as it can before the onset of the flowering phase. Basically it is the period of growth between germination and the beginning of sexual maturity characterised by flowering.

It is standard practice to grow Cannabis seedlings with at least 18 hours light, or even with no dark period at all. This way plants can be grown in a vegetative stage indefinitely, (mother plants for clone production for example) providing the correct light and nutrients are always available, and the ph is kept in check. It’s up to the gardener to decide when to force the plant to flower.

Light needed for vegetative growth is concentrated at the blue end of the spectrum Growing outdoors the summer sun is exactly the right light for growing plants. Indoors some advise to keep young seedlings under fluorescent lighting for a while but this doesn’t provide them with the correct spectrum for photosynthesis. It is best in our opinion to place seedlings directly under low wattage grow lights, 150/250/400 watt and/or at a good distance away. Once the plants are a few days growing they need to be moved closer to the lamps in order to prevent stretching. Move them as close to the lamp as the tops of any plants would be comfortable.(30-60cm depending on the lamp size.)

Make sure a breeze (oscillating fan) is blowing over the young plants, primarily so they don’t over heat, but furthermore to help strengthen delicate stems by stimulating cellulose production.

Whether growing with hydroponics, or in good old-fashioned soil, the vegetative plant requires the same basic nutrients. Plenty of nitrogen (N) and potassium (K) for vigorous, green growth and maximum chlorophyll production. Phosphorus (P) too is needed but not in such large amounts as later in the flowering stage. A well-balanced feed for the vegetative stage is around NPK: 22.8.28 with added trace elements, however, a seedling growing in a good potting-mix shouldn’t need feeding with fertilizer for the first 2 to 3 weeks.

When growing mother-plants vegetatively, the plant requires more nutrients the bigger it gets. With an EC meter (electrical conductivity) it is possible to measure the amount of nutrient in the feed solution. For a small seedling or clone very little nutrient is required and an EC of between .5 and 1. is good, where as a large bush more than a couple of months old, could use an EC of 1.8 or more. Plants will generally grow according to the size of the root-zone, so, regular re-potting as soon as roots become bound is essential for the best growth. Pinching the growing tips in the vegetative stage causes the plants to branch and become bushy. This can be helpful if you need a shorter plant, (often seedlings are so tall and thin) but just remember that although you will increase the amount of buds, you’ll loose that big main top that so many like to show off with at harvest! Once the light hours are reduced to 14 or less per 24, then most marijuana will start to flower, marking the end of the vegetative stage.

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