How to Plant Marijuana Seeds

This guide is all about planting marijuana seeds in a hydroponic system or in soil.

1. Planting Seeds using Hydroponic systems

2. Planting Seeds in Soil

Do you want all of your valuable seeds to sprout? Sprouting seeds is easy. This page teaches you how.

Some preliminary remarks:

It’s very important that your tools are clean. Plants can get diseases from unclean tools, so wash the tools, trays, etc. with anti-bacterial soap.

Make sure that your clothes and hair don’t have any bugs on them that want to eat plants. In other words, don’t go walking in the woods and then right afterwards planting seeds in your clean growroom.

Planting marijuana seeds sprout the best when the humidity is high, about 60-70%. The temperature should be around 25 Centigrade.

The following 2 sections teach you how to plant seeds. The first section is about planting seeds for use in hydroponic systems. The second section is about planting seeds in soil. The two sections are fairly similar, except for some minor points that have to do with the specific medium.

1. Hydro

Whether you grow in rockwool, perlite, or another medium, it is easiest to start the seeds in rockwool cubes.

You can buy plastic trays with pre-cut rockwool cubes, or you can purchase a big slab of rockwool and cut off small cubes of 1 inch thick and 2 inches tal. Put them in small cups. Make sure that each cup has a hole for drainage, otherwise the roots will rot.

Make a hole in the top of each rockwool cube, wide enough to drop a seed in, about half an inch deep. Water the cubes thoroughly, letting excess water run off.

Drop the seeds in the holes, one seed per hole.

Put the cubes under fluorescents lights. It doesn’t have to be strong light, 40 Watts will do. Hang the lights 2-3 inches above the cubes. This will provide maximum exposure to the light, and the warmth generated by the lights will facilitate sprouting. Keep the lights on all day and night.

Make sure that the room temperature is about 25 C or 90 F. If necessary, buy a heating mat from a gardening store and put it under the cups or tray.

After several days, the seeds will sprout.

When the seeds sprout, check daily that the lights are high enough over the seedlings. If necessary, raise the lights to give the seedlings room. At this stage, they grow very fast.

About 3-5 days after the seeds sprout, the roots will show through the bottom of the rockwool cube. This is the right time to transplant the seedlings. Prepare a bigger slab of rockwool by cutting out a space for the cube and water the rockwool thoroughly. Use tepid water so that the seedling won’t get a shock. Carefully take the rockwool cube out of its paper cup or other holder, making sure that you don’t touch the roots that poke through the cube and that the roots don’t get damaged in any other way, such as rubbing the cube against the cup. Place the cube into the hole that you cut out in the big rockwool slab. If at this stage you discover that the hole is not big enough, don’t try to press the cube into the hole. Instead, gently remove the cube and make the hole bigger.

Make sure that the small cube does not sink in the hole lower than the rest of the surface. The small cube should rather stick out a bit. This prevents stem rot, which otherwise might occur if water can form a puddle at the base of the stem.

After the transplanting you can start adding nutrients to the water. There are special mixes for seedlings and transplanted plants. If you use nutrients that are not specifically for seedlings, use half the dosage.

2. Soil

In general, plants don’t like it when hey are transplanted to a different medium than what they are used to. It will give them a shock, so they will stop growing until they get used to the new soil. It is best to keep that in mind from the start.

You can start planting marijuana seeds in several ways. You can use peat cups filled with the same soil mix that you will use for growing the plants to maturity. Peat cups are made of pressed peat and come in different sizes. The roots of the seedling will simply grow through the cup so there is no need to remove the cup when you transplant them.

Another method is a peat pill. These are round, pressed pieces of peat that you soak in water. They will swell up until 4 times its size.

In this chapter, I will use the word ‘cup’ for both the peat cup and the peat pill.

Wet the cup throroughly, letting excess water run off.

Make a small hole in the top of the soil in the peat cup, or in the top the peat pill, about half an inch deep, wide enough to drop a seed in.

Drop the seeds in the holes, one seed per hole. Put the cups on a tray that lets excess water run off.

Put the cups under fluorescents lights. It doesn’t have to be strong light, 40 Watts will do. Hang the lights 2-3 inches above the top of the tray. This will provide maximum exposure to the light, and the warmth generated by the lights will facilitate sprouting. Keep the lights on all day and night.

Make sure that the room temperature is about 25 C or 90 F. If necessary, buy a heating mat from a gardening store and put it under the tray. After several days, the seeds will sprout.

Check twice a day if the medium is moist enough. If you touch the dirt or peat with your finger and it feels moist, it is moist enough. If it feels dry to the touch, add a bit of water, letting excess water run off. Do not soak the cup thoroughly, because the seed might start to rot. Just a bit of water should do. The water should be tepid, not cold. Cold water provides a nasty shock to the sprouting seeds, adding stress and possibly delay sprouting. Do not add any nutrients at this point. Just plain, tepid water.

When the seeds sprout, check daily that the lights are high enough over the seedlings. If necessary, raise the lights to give the seedlings room. At this stage, they grow very fast.

About 3-5 days after the seeds sprout, the roots will show through the bottom of the cup. This is the right time to transplant the seedlings. Prepare a pot with the dirt mix of your choice. Water the pot thoroughly, letting excess water run off. Use tepid water so that the seedling won’t get a shock. Make a hole in the middle of the pot, big enough to fit the cup in. Carefully pick up the cup, making sure that you don’t touch the roots that poke through the cup and that the roots don’t get damaged in any way, such as rubbing the cup against anything. Place the cup into the hole that you dug in the dirt. If at this stage you discover that the hole is not big enough, don’t try to press the cup into the hole. Instead, gently remove the cup and make the hole bigger.

MMake sure that the cup does not sink in the hole lower than the rest of the surface. The cup should rather stick out a bit. This prevents stem rot, which otherwise might occur if water can form a puddle at the base of the stem.

After the transplanting you can start adding nutrients to the water. There are special mixes for seedlings and transplanted plants. If you use nutrients that are not specifically for seedlings, use half the dosage.

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