Weed Seeds Not Sprouting | Possible Causes and How to Prevent It

  • Home
  • Blog
  • Weed Seeds Not Sprouting | Possible Causes and How to Prevent It

by Morgan

Last update:

August 30, 2023

How To Choose The Right Lighting For Your Marijuana Grow Room

Weed seeds not sprouting? We have all been there before, and it can be extremely frustrating and disappointing, especially if you have just invested a lot of money on your seeds. You may have even tried different methods to get them to grow, but nothing seems to work. Several reasons make the seeds dormant.

We're here to assist you. You should be able to get your weed seeds to grow as quickly as possible after reading this, so you can start enjoying your new plant as soon as possible. This article can assist you if you have difficulties sprouting your weed seeds.

🌿  Join my "growing" community 
of 5000+ happy
cannabis farmers! 👩‍🌾

Receive my weekly articles in marijuana growing,
from seeds to smoke! 
— Morgan, 420GreenThumb 🌱

Why Won't My Cannabis Seeds Sprout?

If you are a cannabis seed grower, you will know how frustrating it can be when your seeds don't germinate. It can be a very simple problem to fix, but it can also have several different causes. Here are several common reasons for Weed seeds not sprouting:

Not Using New or Sterilized Soil and Pots

This is important if you use plastic pots to ensure your seeds germinate. The chemicals from the plastic itself can cause your seeds to rot before they even have a chance to germinate. Sterilizing your potting medium will eliminate unwanted pests or pathogens that would otherwise kill off your seedlings before they have even had a chance to sprout!

Too Much Moisture

This is a top reason that prevents the cannabis seeds from germinating properly. When too much water gets into contact with the seedling, it may prevent it from getting enough oxygen through its roots while they are still developing. If this happens, you end up with something called 'damping off.'

Bad Seeds

growing process

This is usually the first thing you should check if your seedlings aren't germinating.If you've purchased your seeds from an unreliable supplier or haven't stored them properly, they might not have much chance of proper growth. 

You can even get bad seeds from a reputable supplier if they're old or have been exposed to too much moisture. If you suspect the seed quality is the issue, contact the retailer/supplier to see if they'll replace them for you.

Handling Seeds with Bare Hands

Seeds can be contaminated with bacteria and fungi from your fingers. It can cause the seeds to rot before they germinate or kill the seedling after it sprouts. Always use gloves when handling seeds, especially if you have cuts or scratches on your hands that could allow bacteria to enter the seed coating.

Seeds Buried Too Shallow or Too Deep

To germinate seeds, ensure to plant them at the correct depth. If you plant them too shallow, they will not have enough space to grow roots and die. If you plant them too deeply, their stems and leaves may not be able to reach sunlight, and that'll compromise photosynthesis.

a person planting the seed

Dry Soil/Growing Matter

It's a common problem with cannabis seeds. If you don't have enough water available to germinate cannabis seeds, they won't be able to absorb what they need to decompress and start growing roots. So it would help if you made sure that there is plenty of moisture in the soil so that your seedlings can absorb it when they need it most.

Contaminated Water

You should only use distilled water for watering your plants because tap water contains chlorine and other chemicals that can harm your seedlings and derail the germination process. Tap water also contains minerals like calcium and magnesium, which can build up over time in your soil and potentially damage root systems if not removed before planting your seeds.

a plant and person's hand working around it

Pests and Diseases

Insects or other pests may be eating the seeds or their roots, or they may have been infected by a disease. If you notice pests and even weed diseases on your plants, you should consider consulting an expert for pesticides, and if you don't have many plants, you may throw away all the plants and start again.

Soil too Firm/Hard

If the soil is too hard for the seeds to break through, it will prevent them from germinating properly. Softer soils are better for germination than hard ones because they don't compact as easily during watering cycles and provide more oxygen at the soil's surface, where seedlings develop their roots.

weed growing

Tips For Sprouting Stubborn Weed Seeds

Some weed seeds are very difficult to sprout, even with the best weed seed germination methods. However, there are ways to make stubborn weeds grow.


Soaking is one of the easiest ways to soften the seed shell and germinate stubborn weed seeds. Soak your seeds in a glass of water for 24 hours before planting them in the soil. This helps remove some of the natural inhibitors that prevent germination, making them more likely to sprout when planted.

You may also consider adding the following boosters and fertilizers to increase the germination rate:

  • Fulvic or Gibberellic acid
  • Germination booster
  • Hydrogen peroxide


Try chilling them instead if you can't find a warm place to put your seeds. Place your weed seeds in a Ziploc bag or container and put them in your refrigerator for two days; this will help break down the internal inhibitors that prevent germination! Then follow step 1 above when you're ready to plant them outdoors (or indoors).

Poking Holes

Try using a toothpick or other pointed object to poke holes through the seed coatings. This will also help improve germination rates by allowing moisture to reach the embryo within the seed.

Use the Wet Paper Towel method

Try using a paper towel or newspaper underneath your germinating seeds - this will help keep them moist without getting their roots wet (which is usually not a good thing). Plus, it's just a nice way of keeping things organized!

Light Exposure

Some weed species require light to germinate. You'll require more grow light for indoor seed germination. For example, tomato and pepper seeds will not sprout if they are buried too deep in the soil or if they are kept in darkness. If you have a lot of weed seeds that do not germinate, try to expose them to light by placing them on top of the soil or using a transparent container such as an aquarium. Adequate light will help germinate the cannabis seeds properly and in less time.

Use Fine Sand Instead of Soil If at All Possible

This type of sand allows more oxygen into the mix than regular dirt does, which helps your seeds breathe easier while they wait for sprouting time! You can purchase fine sand at any garden center or hardware store in your area if you don't want to use regular sand found outside on the beach or in playgrounds.

Ensure Ideal Soil Temperature

The ideal soil temperature for your weed seeds is between 70-80 degrees Fahrenheit (21-27 degrees Celsius). However, if your home isn't warm enough or if it gets too hot in there (over 80 degrees Fahrenheit), you may want to place an aquarium heater on one side of your growing container so that the heater generates the heat and promotes faster germination and growth into a strong cannabis plant.

How Long Can It Take for Weed Seeds to Sprout and Grow into Cannabis Plants?

The answer depends on several factors, including the type of seed, germination method, and storage conditions. But generally speaking, most marijuana seeds will begin to germinate within 5-10 after being planted in the ground or on a heat mat.

Some growers claim that even the most stubborn seeds will begin to grow within 2-to 3 weeks if kept warm and moist. However, this isn't always true — sometimes, you may need to wait several days before any cannabis growth occurs.

The same goes for cold-climate growers: It's not uncommon for marijuana seeds to remain dormant for weeks or more during the winter months, even if they were planted in soil outdoors in early summer.

Also, some marijuana strains have been shown to have germination rates as low as 15%, and others can have germination rates over 90%.

Different types of marijuana seeds (feminized vs. regular) will also affect how long it takes to sprout. Feminized seeds are bred to produce female plants and will grow into mature cannabis plants faster than regular seeds because they don't need to wait for male cannabis plants to pollinate them.

the plants growing

How Much Light Do Weed Seeds Need to Germinate Cannabis Seed?

It depends on the type of weed seeds you are looking for. Some weed seeds need more light than others to germinate, especially if they are from a mature female.

When we look at the germination rates of different strains of weed seeds, we can see that some strains like to be in complete darkness while others can handle indirect sunlight.

The main thing to remember is that your germinating cannabis seeds need at least 12-18 hours of daylight to photosynthesize and produce energy. The seedling then uses this light energy to produce its food.

germinated seed

Take the Rights Steps!

Weed seeds not sprouting is the most common problem that can happen. This is because of improper storage and use of the seed. If you want to eliminate this problem, you must follow the cannabis seed germination tips listed above. For example, if you use a container, make sure it is not too small or too large. Also, do not use soil treated with chemical fertilizers or pesticides that may harm the young plants during their flowering and vegetative growth stages.

🌿  Join my "growing" community 
of 5000+ happy
cannabis farmers! 👩‍🌾

Receive my weekly articles in marijuana growing,
from seeds to smoke! 
— Morgan, 420GreenThumb 🌱

Related posts

About the author 


I discovered the benefits of Cannabis at a young age in 2002, with years of trial and error, my knowledge grew just like my plants. As my love for cannabis unfolded I began to teach and learn, trying to gain as much information and practical growing experience.

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}