Experiment: Should You Peel Avocado Seeds to Grow Them?

Abstract

Many people have eaten an avocado, then taken the seed to attempt to grow it into an avocado tree. There are dozens of articles, videos and infographics explaining how to do this, some advise peeling the seed, and some don’t. In my experience, both peeling the seed and not peeling the seed leads to germination – but I wanted to know which way was best. So I devised an experiment and invited my YouTube subscribers to join me. We called it the International Avocado Experiment, and we had participants from all over the world; the USA, UK, Australia, Canada, Singapore, South Korea, Mexico, Malta, and Ukraine. Through our experiment, we found that peeled avocado seeds have a greater germination rate than their unpeeled counterparts, and had a faster average germination time.

Question

The question we asked and looked to answer was essentially ‘should you peel avocado seeds?’, but we formed it in a slightly more scientific way:

         Does peeling an avocado seed increase the chance and speed of germination when using the water and toothpick method?

Hypothesis

That peeling an avocado seed will increase the chance and speed of germination when using the water and toothpick method.

Experiment

On September 17, 2020, I invited my audience to participate. They were to begin their trials by October 17, 2020, and we would finalise our experiments and report our results on December 17, 2020. This gave us between 2-3 months to germinate seeds, which is a reasonable time to experience germination.

There were 27 individual trials run. Each trial had two seeds; a control, unpeeled seed – and an experimental, peeled seed. Each seed was started using the water and toothpick method. Whereby seeds are half held in water using toothpicks placed carefully in the outer layer of the seed (endosperm) and which rest on the rim of a glass or jar.  Participants noted the date which each seed was placed in water. Participants maintained clean water over the course of the experiment, changing the water from both vessels at the same time. Once a seed started to show a root protruding from below the seed, that’s when the date of germination was counted. Germination happens prior to this, but as an easy way of measuring successful germination, this is the method we decided upon.

On December 17, 2020, participants recorded their results on a form on this website. They were asked for their country, the date each individual trial was started, whether each avocado seed germinated and if so, when its germination date was.

Results:

27 Trials were reported on the website. There were we were answering through our results – whether a peeled seed had a higher chance of germination within the 2-3 month period, and whether peeled seeds were faster germinators.

Did the avocado seeds germinate?

	Control (Unpeeled)	Experiment (Peeled)
Number of successful germinated seeds	15 (55.6%)	19 (70.4%)

We saw a greater number of experimental peeled seeds germinating.

How long did it take for each avocado seed to germinate?

	Control total days	Experiment Total days
	12	17
	20	18
	24	22
	34	24
	34	24
	36	25
	44	26
	45	26
	53	29
	60	30
	66	36
	76	37
	85	42
		47
		49
		52
		57
		67
		78
Average (Mean):	44.46666667	37.31578947

The start date and germination date were used to calculate the number of days elapsed between placing each avocado seed in water and its germination date. Only the seeds which germinated were considered. The average (mean) was then calculated for each experiment group.

The average number of days for germination for the experimental, peeled group, was 37.3 days. This was 7.2 days faster than the average number of days the control, unpeeled group (44.5 days). (Rounding to the nearest tenth).

Discussion:

Our results showed that peeled avocado seeds have both a higher probability of germination, and a higher speed of germination than their unpeeled counterparts. Interestingly, the fastest germinating seed in the experiment was an unpeeled seed (12 days), but when calculating the mean, it showed that when taking the seeds which germinated within the trial period, peeled seeds had a faster rate. (Please note that an error was made in the video, the slowest germinating seed was also an unpeeled seed, at 85 days).

The experiment had a fairly small sample size. In future experiments, to enhance reliability, larger sample sizes would be ideal. Further inquiries as to the different conditions of germination may be helpful in gaining a full understanding of avocado seeds. A future question may be investigating if peeled seeds maintain their higher probability and speed when in different germination methods (such as in soil or sphagnum moss).

Conclusion:

The results of this experiment showed that it is better to peel avocado seeds before germinating them with the water and toothpick method.

Thank you to all those who were involved in the experiment! You can watch the video here: