Why Are My Cannabis Seedlings Growing So Slow?

We all want our cannabis seedlings to grow quickly and evolve into strong and healthy plants. To do this, you need to create the right environmental conditions for seedling growth. Many cannabis growers get antsy during the germination process. They worry about if their plants are growing fast enough and if germination is on track. Below, we’ll discuss some reasons why seedlings may take longer to germinate and answer common questions about the seedling growth process.

Having concerns about how quickly your cannabis seedlings are growing is common. Growth of the seedling will appear to be slow at first because you don’t see a lot happening above the soil. But most of the work is being done below the soil. The root system is growing below to support the growth of the plant later.

Some of the reasons your seedlings could be growing slow include:

  • Low quality seeds
  • Low quality soil
  • Under or overwatering
  • Nutrient toxicity or nutrient deficiency
  • Using cannabis fertilizer too early

The initial germination stage will take a while. So, be patient. Once the plant does start to germinate you’ll notice that it won’t look like traditional cannabis leaves. This is perfectly normal. Seedlings develop a set of oval-shaped cotyledons before the “true leaves” develop.

How long does it take for cannabis seeds to germinate?

The length of time it takes for seedlings to grow can depend on several factors – type of seed, growing conditions, soil quality, and more. Generally, you can expect to see a seed germinate in 2 to 10 days. In some cases, it can take up to 14 days or longer.

Example of Cannabis checking cannabis growth

Can you speed up the germination process?

The initial stages of germination are about being patient as a grower. There isn’t a lot you can do to speed up the process. If you took the proper steps to prepare, you should have success. This means buying high-quality seeds and ensuring the plants have an ideal environment to grow. 

The top mistake many growers make is to try to speed things up. For example, trying to reduce the seed shell thickness, adding too much cannabis fertilizer and trying other techniques to manipulate the germination process. These actions could end up killing your plant and doing more harm than good. Be patient and let the seedlings do their thing naturally.

How big should cannabis plants be after 2 weeks?

The height or size of a plant is a measuring stick that growers typically use to determine if the plant is healthy. The size of the plant at the two-week mark is a common indicator used. Plants are commonly about 2 or 3 inches tall after two weeks. They will also have 2 or 3 sets of leaves. This includes the cotyledons (rounded seed leaves). 

Naturally, results will depend on growing conditions. In addition to the seed quality, soil, relative humidity, pot size, watering and lighting will affect its size. For example, if you have a weaker or improper light source, your seedling may start to stretch out to try to get closer to the light source.

Can cannabis fertilizer help seedlings grow faster?

The use of fertilizer is an important part of cannabis growing, but not as much during the germination process. Seedlings are initially “autotrophic” meaning they are capable of nourishing themselves only with the nutrient stores within the seed. Once plants have grown 3-4 sets of true leaves and start photosynthesizing, seedlings become “heterotrophic” and require nutrients from the media. This is why most seedlings require none or a very low dosage of nutrients in the first couple of weeks. The plants are very sensitive during the initial growth stage. All they need is water and light. But there may be some instances where fertilizer may be required. 

If you add too much cannabis fertilizer, seedlings could get nutrient burn. Plants will not be able to absorb the excess nutrients causing a phytotoxicity in the young seedling. This is why it is important to use low fertilizer rates in the early seedling stages. The common signs for nutrient issues during the seedling stage are dark green tips and leaves with burnt tips. After the two-week mark, you can start your cannabis fertilization process.

Want to learn about how to visually read your cannabis plants for problems? Check out how to ‘Listen to your Plants’ by downloading our Cannabis Fertilizer Growers Handbook and learn how to get 5X more buds with 80% less fertilizer.Cannabis Fertilizer Growers Guide from Plant-Prod



Plant-Prod is a manufacturer of water soluble cannabis fertilizers. The choice of growers from California to Maine for over 70 years, we formulate with everything from chelated iron, to calcium nitrate and zinc fertilizer in order to help you get bigger buds for your buck. Click here to find a Plant-Prod fertilizer supplier near you.

array(2) { [0]=> int(32) [1]=> int(94) }