Sour Diesel Auto Cannabis Strain Week-by-Week Guide

Our week-by-week guide for this super sour Sativa!
02 December 2020
13 min read
Sour Diesel Auto Cannabis Strain Week-by-Week Guide

  • 1. History
  • 2. Specifications
  • 3. Week-by-week guide
  • 3. a. Week 1 - germination
  • 3. b. Week 2 - vegetative stage
  • 3. c. Week 3 - vegetative stage
  • 3. d. Week 4 - vegetative stage
  • 3. e. Week 5 - pre-flowering stage
  • 3. f. Week 6 - flowering stage
  • 3. g. Week 7 - flowering stage
  • 3. h. Week 8 - flowering stage
  • 3. i. Week 9 - harvesting
  • 4. What to expect?
  • 5. In conclusion

1. History

There’s no much info about the origins of this super sour strain because Sour Diesel dates back to the ‘90s and back then, cannabis wasn’t regulated and most of the breeders didn’t keep track of their crosses.

Sour Diesel’s history begins at the beginning of the 1990s, despite no one knowing where it all started, it’s agreed that it was on the West Coast, in the US.


Sour diesel auto guide: history

The history of Sour Diesel.

Back then, Chemdawg was really popular and was being grown by a group of friends which discovered a phenotype that stood out, this phenotype quickly got everyone’s attention and soon became almost impossible to get because this group of growers would never sell seeds or clones, only flowers.

As soon as the word spread, everyone was trying to get their hands on this Chemdawg phenotype, especially A.J. who was a skillful breeder and wanted to get those genetics to make it available to the public.

A.J. was an experienced breeder who wanted to get those genetics to smoke but also wanted to sell the flowers, as time got by, A.J. bought flowers every day to see if, by a chance, he could get a couple of seeds in the buds and after a couple of months, he was fortunate enough to find five seeds, and all of them sprouted.


Sour diesel auto guide: history

Cannabis plant with several colas thriving.

What he didn’t know is that those seeds weren’t what he thought because the group of growers had crossed them with another plant, so the seeds A.J. were quite good, although not what he was looking for so in an attempt to make the most out of them, he crossed his plants to a Super Skunk, which resulted in the Sour Diesel we know.

Have in mind that this theory hasn’t been confirmed because it’s not possible to track exactly where this strain came from but what we all know is that Sour Diesel became a classic for its unique blend of citrus adn gas, giving birth to several famous strains.


2. Specifications

Fast Buds’ version of this super-strong Sativa is really easy to grow, taking 9-10 weeks from seed to harvest and growing up to 120cm, you can expect yields of up to 550gr/m2 and beautiful buds with 21% THC.

The flowers develop very dense, large, and come with an extremely strong aroma that truly represents gassy cultivars, thanks to the delicious mix of fuel, citrus, pine, and sandalwood.

Sour Diesel Auto
Sour Diesel Auto
Sativa 65%/Indica 35%
Sour Diesel Autoflowering
9 – 10 weeks
450 – 550 gr/m2
90 – 120 cm
Up to 21%
< 1%
Buy seeds from 9,00 €
1 fem
9,00 €
2 fem
16,00 €
3 fem
24,00 €
5 fem
40,00 €
10 fem
70,00 €
25 fem
150,00 €
50 fem
250,00 €
100 fem
420,00 €
500 fem
1 450,00 €
1000 fem
2 400,00 €
3 fem
Add to Cart
24,00 €

The buds also develop a thick layer of trichomes all over, and if you think the aroma is strong, wait until you feel the effect.

Despite the Kushy aroma, Sour Diesel Auto offers a Sativa-like effect that will keep you flying all day long, with a cerebral effect that keeps you energized and motivated, perfect for gaming, drawing, writing, or just enjoying with friends.

3. Week-by-Week Guide

This article serves as a guideline, this way you know what to expect when growing the auto version of this classic strain, here you can see the conditions kept throughout this grow report and the results obtained by several growers.


Grow Specifications
Light Fixture: LED
Light Cycle: 20/4
Humidity: 45-65%
Temperature: 22-30°C
Grow Space: Indoor
Nutrients: Synthetic
PH level: 5.5-6.2
Seed to Harvest: 9-10 weeks


Have in mind that this written timeline was made to aid you when growing this strain, even though you’ll be able to grow your plants in most conditions, you should adjust your growing setup depending on the conditions and the specific strain, our Sour Diesel Auto in this case.

Week 1 - Germination

As always, this is the first week and it’s when this Sour Diesel Auto week-by-week guide starts. 

This grow cycle starts by germinating a couple of seeds using the paper towel method and then transferring them to the medium of choice.

Remember that we usually recommend soaking the seeds in water for up to 48hs, this will help soften the seed’s shell and will make it easier for the water to reach the embryo, increasing the chances of germination.


Height: 3cm
pH: 5.8
Humidity: 65%
Temperature: 30°C
Watering: 100ml


Have in mind that cannabis seeds germinate under certain conditions so even though we recommend soaking them in water, you can germinate them however you want, and as long as you keep them under certain conditions, you will successfully germinate them.

Started 4 new seeds out in a paper towel, getting ready to plant into pots as soon as they have germinated. -GrowBuv

So, if it’s your first time growing cannabis, you should keep the relative humidity around 90% and the temperature between 18-25°C, once your seedling has come out of the soil, you can keep the same temperature and the humidity a bit lower, around 65-70%.


Sour diesel auto guide: week 1

Seed successfully germinated courtesy of GrowBuv1,2, Vam4203.

Remember that if you don’t have the proper equipment to adjust and maintain proper conditions, you can buy a plastic dome at your local grow-shop or make one with a plastic bottle or any other type of plastic container.

This will help keep the proper humidity level, helping your seedling thrive, although have in mind that it will get harder and harder to improvise as your plant grows so it’s better to invest a bit to avoid having problems further down the grow cycle.


Week 2  - Vegetative stage

If everything goes as it should, your plant should have come out of the soil and started growing true leaves, each of these fingers is known as “apex” and is a characteristic that plants heir from their parents.

The number of apexes won’t influence your plant in any way, but the first 3-fingered leaves are the “true leaves” and as soon as 2-3 pairs of true leaves have completely developed, you can start training your plant slowly.


Height: 10cm
pH: 6.3
Humidity: 50%
Temperature: 23°C
Watering: 150ml


So, as soon as you see three pairs of leaves, you can start plant training, it doesn’t matter if it’s LST or HST, as long as you do it properly you will reap the benefits, although we don’t recommend beginner growers to perform HST techniques because it can end up stressing your plants too much.

Just remember that if you don’t have experience with plant training you can wait a couple of days more to make sure you don’t have problems.

Also, as soon as you see the first true leaves, you can start feeding a low dose of Grow nutrients in a 3-1-2 ratio, meaning your plant will get more Nitrogen which is the mineral it needs to develop plant matter but will also get lower doses of the other macronutrients and micronutrients.


Sour diesel auto guide: week 2

Sour Diesel Auto on week 2 of the vegetative stage by Foxtrotoscar from Grow Diaries.

Remember that depending on the type of nutrient and medium you’re using, you will have to check and adjust the nutrient solution’s pH because the water’s pH is what will allow your plant to absorbs certain nutrients, even though you’re providing the nutrients your plant needs, your plant won’t be able to feed if the pH level isn’t within the proper range.

Week 3  - Vegetative stage

Around week 3 (if everything goes as planned), your plant will have already established the roots and you’ll see an explosion in plant growth. 

By now, your plant should have developed quite a lot of foliage and should have grown quite a bit. 


Height: 30cm
pH: 5.5
Humidity: 50%
Temperature: 26°C
Watering: 400ml


Even though you could start plant training before, week 3 is when most plants have a nice structure that will make it easy for you to tie down the branches, for example.

Depending on what type of plant training you want to perform, you have to wait until 3 pairs of leaves are completely developed or once the internodal space is good enough to suit what you’re aiming for.


Sour diesel auto guide: week 3

Super healthy plant by wheedtobeus420.

You can have similar results when performing both LST and HST techniques, but usually, LST takes more time because you have to do it gradually, day-after-day but will stress your plants way less than HST techniques such as topping or fimming.

So you should have in mind what you aim for and know how to do it, always checking and adjusting your growing environment to allow your plant to recover as fast as it can because when plants are stressed, they can take a couple of days to fully recover and continue growing.


Week 4  - Vegetative stage

Week 4 marks the week before the pre-flowering stage, as your plant slowly nears the pre-flowering stage, you will see the flowering sites turning light green and as soon as your plant is sexually mature, it will start developing stigmas which are the white hairs that sign the beginning of the flowering stage.


Height: 50cm
pH: 5.5
Humidity: 65%
Temperature: 25°C
Watering: 500ml


Usually, male cannabis plants show signs of their sex a couple of weeks before the female plants, so if you’re growing other non-feminized strains you should keep a close eye on the pollen sacs.

This happens because pollen sacs contain pollen which can end up pollinating your female plants, thus producing seeds and ruining your harvest so make sure you keep an eye on all of your plants to avoid this.


Sour diesel auto guide: week 4

Cannabis plant one week before pre-flowering by Zurban_Poisonia.

As always, our seeds are feminized so you won’t have to worry about this but despite not having male plants,  it’s essential you check on your plants every day to prevent bugs or mold which can end up attacking your plants and you won’t even see them due to their small size.

Week 5  - Pre-flowering stage

The fifth week marks the beginning of the pre-flowering stage, as you can see in the photos below, the plant will start to show signs of its sex and it’s also a sign that your plant is sexually mature.

When your plant is starting to show white hairs, it will also start developing trichomes so if it hasn’t started smelling now, it will in the following days so be careful and watch out because you will need a way of masking or eliminating the smell further along.


Height: 60cm
pH: 6.5
Humidity: 55%
Temperature: 28°C
Watering: 700ml


As you may know, cannabis plants need more phosphorus and potassium to develop the buds so as soon as you see the white hairs, you should slowly start feeding Bloom nutrients in a 1-2-3 ratio and, depending on the type of medium you’re growing in, you will have to provide calcium, magnesium and other trace elements that cannabis plants need to thrive.


Sour diesel auto guide: week 5

Sour Diesel Auto in the pre-flowering stage by DrWeird.

As said above, cannabis plants thrive in certain conditions so it’s essential you check them every day and adjust it if necessary, during the pre-flowering stage you should keep the temperature between 18-25°C and in a relative humidity of around 55-60%.

Also, if you were performing any kind of plant training, you should stop once the buds start to form, this is to avoid stressing your plants because stressing them during the flowering stage can end up affecting the yields and quality of your harvest, so by now, you should have reached the desired structure and size.


Week 6  - Flowering stage

Week 6 marks the first half of the flowering stage, by now your plants should be in full-flowering mode and as the week passes, your grow space will start to reek of a delicious cannabis smell.

If you haven’t installed it yet, make sure you install a carbon filter and exhaust to help eliminate the smell because this plant will leave your whole plant smelling like straight diesel.


Height: 65cm
pH: 6.5
Humidity: 45%
Temperature: 28°C
Watering: 1000ml


Now, if you can’t afford a good carbon filter, you can buy odor neutralizers that will mask the smell a bit, just have in mind that it won’t eliminate the smell, so it won’t be as effective as a carbon filter.

Also, this is the stage when most growers suffer from bugs, so you should keep an eye on your plants and act as soon as you see signs of any type of bugs.


Sour diesel auto guide: week 6

Cannabis plant on full-flowering mode by DrWeird.

As the flowers take form, it’s most likely you get mold if you don’t control the environment, especially the humidity levels.

This happens because mold thrives in slightly warm and humid climates and it can be hard to get rid of it because sometimes they will get bud rot and eat your buds inside out, so make sure you have complete control over your grow tent.

Week 7  - Flowering stage

The seventh week is when you should start feeding a full dose of Bloom nutrients, by now your plant needs just a couple of weeks for the buds to fatten up so you should make sure you provide everything your plant needs to develop the buds properly, just make sure you don’t overfeed because it could really stunt growth and end up affecting the yields.


Height: 65cm
pH: 6.5
Humidity: 45%
Temperature: 28°C
Watering: 1100ml


As your grow cycle continues and you get near harvest week, you should make sure the conditions are proper to avoid bugs, mold, and stressing your plants so nearing the second half of the flowering stage, you should keep the humidity around 50% and the temperatures between 18-25°C.


Sour diesel auto guide: week 7

Sour Diesel 2 weeks from harvest by DrWeird.

As you can see in the photos above, the buds have taken form but still need more time to fatten up, even if you see some pistils turning brown, don’t worry, let them develop and keep up the good work, you’ll be harvesting your buds in no time!

Week 8  - Flowering stage

Week 8 marks the second half of the flowering stage, by now the smell should be super loud and the trichomes should be visible from afar. 

You’ll be harvesting your plants in the next week but don’t get confused, even if the trichomes begin turning cloudy and some of the pistils are brown, you shouldn’t harvest yet, pay attention to the calyxes.


Height: 65cm
pH: 6.5
Humidity: 50%
Temperature: 24°C
Watering: 1200ml


Even though it may seem that your plant is ready for harvest, you should use a jeweler’s loupe or a microscope to take a look at the trichomes and see them clearly, by doing this, you’ll know exactly when to harvest your plants.

Also, depending on the type of nutrients you should start flushing, this will remove the built-up salt on the medium and the roots, enhancing the aroma and flavor.


Sour diesel auto guide: week 8

Cannabis plant one week before harvest courtesy of Foxtrotoscar.

Remember that depending on how you’re growing and your water source, you should also check and adjust the pH and PPM because water can contain trace elements and will still be adding minerals to the soil instead of completely washing them off.


Week 9  - Harvesting

Week 9 marks the last week of this grow cycle, our Sour Diesel Auto may take up to 10 weeks but in this case, it took a week less.

If you have already started flushing, you will see the leaves starting to yellow, this is a sign that you’re flushing correctly, have in mind that if you see yellowing in any other stage it could be a nutrient deficiency but if it happens when flushing it’s completely normal.


Height: 65cm
pH: 6.5
Humidity: 60%
Temperature: 23°C
Watering: 1300ml


As you should know by now, after harvesting you still need to dry and cure your buds so before cutting the branches, make sure you have your drying room ready to hang them as soon as you harvest them.

A good tip is to leave you plants in complete darkness for up to 48hs before harvesting, it’s said that this will boost trichome production and your buds will get even frostier, so try different techniques and reach your own conclusions.


Sour diesel auto guide: week 9

Completely mature sour diesel grown by Foxtrotoscar.

Remember that during the drying process, the smell can be even stronger than during the flowering stage so make sure you have a way to mask the smell such as an odor neutralizer or a carbon filter with an exhaust fan on low, this way you don’t risk getting in trouble.

4. What to expect?

Now that your plants are already drying, you have to wait around 15 days before you can start the curing process which lasts a minimum of 2 weeks so if you’re eager to know exactly how your buds will smell, here’s what our growers have reported.

You can expect the old-school blend of sandalwood, pepper, and earthy terpenes with hints of gas, sour, and citrus which is a true representation of gassy strains, and consists of the following main terpenes:

  • Pinene
  • Caryophyllene
  • Humulene
  • Myrcene

The main terpenes in combination with the secondary terpenes that you will see in the chart below provide a very Sativa-like high that will keep you energized and motivated throughout the whole day.


Sour diesel auto guide: sour diesel terpene profile

Sour diesel terpene profile.

This terpene profile offers an extremely gassy flavor that results in a 65% Sativa and 35% Indica that will enhance your creativity and keep you sky-high all day long, making it perfect to play videogames, watch movies, or just hanging out with friends.


Sour diesel auto guide: buds after harvest

Beautiful Sour Diesel Auto buds after harvest courtesy of Thomas and ElChicoDelaWeed.

Growers have reported feeling happy, creative, and energetic but also that it can be too much for those who are not used to strong Sativa effects, other than that, no negative effects have been reported.

5. In conclusion

If you’re looking to grow some classic Sativa genetics, you must try this one. This Sativa-dominant delivers a strong effect that will give you an energy boost and allow you to go through the day and doing your chores without a problem.

If you have grown this strain before, please help fellow growers with a couple of tips to improve their growing skills, leave a comment in the comment section below!



External references

  1. Stomata and Trichome Development. - V, Vadivel. (2020). 
  2. Terpene Synthases and Terpene Variation in Cannabis sativa. Plant Physiology. - Booth, Judith & Yuen, Mack & Jancsik, Sharon & Madilao, Lina & Page, Jonathan & Bohlmann, Joerg. (2020).
02 December 2020