Posted on

how many seeds do you need to grow a plant

How Many Seeds to Plant Per Hole, Pot, or Cell?

I recently got an email from Sally with a familiar question. It’s the same exact question that I had when I was a beginner gardener and wondered how to start seeds:

“I’m sure this is a silly question, but I always see it recommended to plant more than one seed per hole. But why? I just got a seed starting kit with some seeds and want to make sure I’m using them efficiently. Can you help me out?”

It’s a great question, Sally! Understanding the answer to this question will improve your understanding of gardening and seed starting in general, because the answer hinges on an important concept: seed germination.

Listen to this post on the Epic Gardening Podcast:

Subscribe to the Epic Gardening Podcast on iTunes

Video Guide

Answer One: Seed Germination Rates

Not all seeds are created equal. Some plant species have higher germination rates than others. Even within a single plant type, some of the seeds are older than others, causing the germination rate to go down.

Imagine you’re growing arugula and the average germination rate is 90%. If you plant a 72 plant starter tray with one arugula seed per insert, you can expect only 65 of those plant inserts to actually germinate (72 x 90%).

Now imagine you plant three arugula seeds per insert. Each of these seeds has a 10% chance of failing, so the probability of them all failing is 10% x 10% x 10% = 0.1%. This means that you are 99.9% likely to have the seeds in that cell germinate. So in a tray of 72 inserts, it would be extremely unlikely you would have any seeds not germinate — barring other factors that affect seed germination.

In short: Planting more seeds per hole increases chance you have perfect germination rates.

Answer Two: Seedling Selection

Just like not all seeds are created equal from a germination standpoint, not all seeds germinate equally. Sometimes you have a seed that shoots off like a rocket and becomes too leggy. If this was the only seed in your insert, you’d be forced to use it.

By planting 2-3 seeds per cell, you allow yourself to luxury of choosing the seedlings that look the strongest. All you have to do is determine which one you like the most, then snip off the other seedlings to kill them.

Exceptions to The Rule

Like most things in gardening, there are always exceptions to this rule of 2-3 seeds per hole.

If you’re planting large seeds like cucumbers, melons, or pumpkins, you should only use one seed per hole. However, you can still plant seeds close together and then thin them out once they’ve established themselves. You just want to avoid crowding these large seeds together so you don’t mess up the germination process.

If you’re growing certain herbs (cilantro, dill, basil), you can get away with planting multiple seeds per hole and leaving them all there as they germinate. These plants can handle being planted right next to each other and basically become one larger, bushier plant.

Now that you know how many seeds to plant per pot, you have a deeper understanding of seed germination in general. For more on seed starting, please check out the simple seed starting for hydroponics guide.

A common question I get by email is, "How many seeds should I plant in each hole or cell?". It's a good question with a great answer — read on to find out!

How many weed seeds do you need to grow a plant?

To grow weed, you need high quality marijuana seeds. But how many seeds do you need to grow weed? And then there’s the question: how many marijuana plants do you want to grow?

This ultimately determines how many seeds you need. Based on your wishes, you calculate the number of marijuana seeds you need.

How many seeds do I need to grow a weed plant?

You might think that you need one cannabis seed to grow a plant. And basically that’s right. But it is possible that not every seed germinates. After all, you are dealing with a natural product.

So what if you plan to grow five plants and one or more seeds don’t germinate? Then you won’t achieve the intended yield and you have to purchase seeds again. It’s therefore wise to use several seeds per plant.

In order to calculate exactly how many cannabis seeds you need, you have to take two determining factors into account:

  • The type of cannabis seeds (regular seeds or feminized)
  • The germination rate

Type of seeds (regular or feminized)

In this blog we assume that you buy cannabis seeds for growing cannabis. For this you can choose between regular seeds or feminized cannabis seeds. Both types differ from each other and have an influence on the final result. The differences are explained below.

Regular cannabis seeds

With regular cannabis seeds, the genus of the plant has not yet been determined. When choosing regular seeds the chance that the seed will develop into a female plant is about 60%. The chance that the seed develops into a male plant is therefore 40%. And because male plants do not produce buds (read: marijuana), you need several marijuana seeds to increase the chance that you will eventually grow a female plant.

Feminized cannabis seeds

With feminized cannabis seeds you don’t have the risk of a flowering male plant. Because female seeds produce 99.9% of a female weed plant. This is why most growers choose feminized seeds or autoflowering seeds

Auto flowering seeds are basically feminized seeds, but have the advantage that they flower automatically (read more about the difference between feminized cannabis seeds and autoflower seeds). However, feminized seeds are more expensive than regular seeds. Depending on your budget and growing skills you will choose the type of weed seed.

The germination rate

In addition to the type of cannabis seed, nature always has an influence on the germination process. After all, the cannabis seed is a natural product and this means that not every seed is viable and germinates.

From experience we know that 93% of the cannabis seeds grow into a plant. This is of course a very high success rate, but not 100%. So you will have to use extra seeds in order to have the certainty of eventually becoming a weed plant.

We therefore advise you to take into account an average germination percentage of 90% when calculating the number of seeds you need for your cultivation. This gives just that little bit extra certainty.

Reading tip: Our blog about ‘Germinating marijuana seeds’ explains how to optimize the success rate to 100%.

Number of weed seeds needed to grow

Based on the above information it’s quite easy to calculate how many seeds you need to grow weed. For your convenience, we have placed the results in the table below.

Question: How many weed seeds do you need to grow a plant? Here you find all the answers about the number of seeds you need to grow a nice weed plant!