How to Grow Basil - Seed to Harvest Guide
Over the years I've come across lots of gardening guides with lots of amazing tips - but always a bit disparate. I could never find a guide that follows a plant's journey from being in a seed pack to harvest and ending up on the dinner table as a delicious meal - and teaches the gardener exactly what to do at every key step along the way.
So? I decided I'd have to create it myself!
This guide is going to take you from the point of starting a basil seed to harvesting it and enjoying it in a delicious meal. My hope is that this basil growing guide helps you feel comfortable and confident in your Mindful Garden, allowing you to spend more energy simply on enjoying the garden rather than questioning whether or not it's growing properly.
And as always, we answer every question we receive so if there's anything you're unsure of or that we don't cover, just leave a comment below and we'll respond to you!
THREE KEY TIPS FOR GROWING BASIL
Rather than giving you a bunch of scientific basil growing information you might not ever use, I wanted to start by providing my three biggest tips for growing Basil (all of which we go into greater detail on at the appropriate time in the basil growing season):
- Basil Tip #1 - Warmth: To grow basil successfully and for it to thrive, it needs to be in a warm environment at all points. This includes when starting the seeds as well as when transplanting it into the outdoor garden. Ensure that your Seed Starting Station is at least 20C/70F, and be cautious of transplanting it into the outdoor garden until the average night time low temperature is at least 12C (more on this below).
- Basil Tip #2 - Pruning: Ultimately we want to harvest the basil leaves - therefore, the more leaves the better. To promote this, there is a specific way to prune basil (full video below on exactly how to prune basil and how simple it is) that will allow the basil plant to multiply its stem and in turn put out exponentially more leaves.
- Basil Tip #3 - Preserve: Lastly, if we have properly pruned our basil plant, then we will likely have a great excess of basil at the end of the season. At this point, there are a number of ways we can easily preserve it through freezing and canning that will allow us to be enjoying delicious pestos (I share my favourite recipe below!) and meals all through the winter.
Let's now get our basil seeds started indoors and start following our basil baby!
DAY 0: HOW TO START BASIL SEEDS
We start our basil seeds the same as the rest of our seeds, which you can see in this video:
- You'll want to fill a Seed Starting cell to 1cm from the top with Worm Castings Seedling Mix.
- Then add 1x turkey baste of water.
- Normally we would add 5 seeds per plant we want, but with Basil I like to add 10 seeds. Partly because they're so small, but also partly because I notice as lightly lower germination rate with them than other plants such as Kale, Tomatoes, and Cucumbers.
- Add 1x turkey baste of water
- Cover with 1cm of Worm Castings Seedling Mix
- Add 1-2x final turkey bastes of water
Once you have finished those steps, your basil seeds need a warm and moist environment to germinate. Therefore:
- Move them under a grow light in an area that is at least 20C/70F.
- Provide them 1x turkey baste of water every 2-3 days. This will ensure that the seedling mix stays moist and that the seeds successfully germinate.
If you've finished these steps, then you're well on your way to having thriving basil this season!
Over the coming 7 days, simply leave the seed cells underneath the grow light in that warm environment, and provide them a baste of water every 2-3 days.
DAY 7: BASIL GERMINATION (6-14 days)
As we check in here on Day 7, we can see that we have several basil seeds that have successfully germinated and are beginning to grow!
If your seeds have not germinated, don't be alarmed. Basil germination generally takes anywhere from 6-14 days, so it's not uncommon for there to not be any seedlings coming through the surface on Day 7. If none of your basil seeds have come through the surface yet, the two things you want to check on are:
- Temperature: Ensure it is at least 20C/70F in your seed starting station
- Moisture: Ensure that the seedling mix is moist. You can do this by placing the back of your finger on the surface. If it is dry, give it a turkey baste of water. If you feel some moisture, then you should be okay. I water every 2-3 days (this primarily varies depending on temperature and if a fan is being used which would dry them out more quickly).
If you get to Day 14 and there is still no germination, then you will want to start a new round of seeds double checking those variables, as well as doing a seed germination test to ensure that your seeds are indeed still germinating (they won't germinate if they are a few years old)
If they have germinated as the ones in this video, then all we need to do is:
- Keep under the grow light with the grow light on for 12-13 hours per day.
- Keep the temperature around 20C/70F
- Water every 2-3 days
As we do that, they will continue to grow and put on their first set of true leaves.
DAY 21: FIRST TRUE LEAVES
The basil is now a few weeks into growing and slowly but surely beginning to look like a plant. As a smaller vegetable or herb, it is going to look much smaller than some of our other plants (such as Cucumbers and Zucchinis) at this point so don't be alarmed if the leaves are much smaller and lower to the ground.
The important piece to note at this point is that we are beginning to see the first sets of true leaves establishing. The very first set of leaves that comes through is known as the "Seed Leaves" or Cotyledons. Every plant has these and their role is to push through the surface, setup an initial canopy, and allow the plant to begin to grow. The next set of leaves generally looks significantly different and is known as the first set of "True leaves." With basil plants, these true leaves are the ones that we will ultimately be harvesting and therefore also looking to grow as many of as possible (which we will promote through basil pruning).
Other than that, we don't need to do anything differently. Simply leave your basil baby under the grow light for 12-13 hours per day, water it every 2-3 days, keep the environment warm, and it will begin to put on its first sets of true leaves in the coming weeks!
Next 30 days: Allow it to just grow.
When to move it outside
DAY 56: HOW TO PRUNE BASIL
Because Basil loves a warm environment and is a fairly small plant, we can start them inside well before they move outdoors. Because of this, I actually do my first pruning while the plant is indoors.
This is one of the most critical parts of growing basil - proper pruning.
Ultimately, we want as many basil leaves as possible as that's what we harvest and eat. And to promote leaf production and foliage growth, we need to prune the basil plant.
Basil plants develop distinct nodes that new leaves will grow out of. If we prune the plant just above this node, then the stem will split into 2 new stems that will all put out new leaves. As we continue to do this over the course of the season, the number of stems goes from 1 to 2 to 4 to 8 to 16 and beyond and as a result you end up with a very bushy basil plant with an abundance of leaves to harvest.
As you'll see in one of the upcoming videos, this pruning immediately creates a bushier plant and we will continue to prune in the manner on a biweekly basis to maximize leaf growth.
DAY 70: HARDENING OFF BASIL TO GROW OUTDOORS
Depending on where you live and when you start your seeds, you might be able to transplant your basil plants earlier than Day 70.
What's of most importance here is that you harden them off over the course of several days and ensure that the average night time low temperature is at least 12C. If it is cooler, hang tight as basil really struggles in cold temperatures.
Hardening off is the process of preparing your basil plant for the outdoors. It has been growing in a very comfortable and stable environment indoors but is about to be moved to an environment that is very volatile and intense. As such, we want to prepare it for this environment over the course of a multi-day period:
- Day 1: Put the basil plant outside in direct sun for 2 hours
- Day 2: Put the basil plant out in direct sun for 4 hours
- Day 3: Put the basil plant out in direct sun for 6 hours
- Day 4: Put the basil plant out in direct sun for 8 hours
- Day 5: Put the basil plant out in direct sun for 10 hours
- Day 6: Put the basil plant out in direct sun for 12 hours
- Day 7: Leave the basil plant outside over night
- Day 8-10: Ensure night time low temperature is above 12C and transplant the basil plant.
This process ensures that the basil plant is acclimated for the outdoors so that it will thrive in its forever home. As you go through this process, expect the plant to wilt, droop, and display fatigue. This is all 100% normal and following the 10 day hardening off schedule above I have never lost a plant.
When you get to the end of this 10 day period, your basil plant is ready to be transplanted with worm castings into its forever home in the outdoor garden!
DAY 77: HOW TO TRANSPLANT AND FERTILIZE BASIL
To ensure your basil plant successfully transitions into the outdoor garden, you want to make sure:
- It has gone through the 10-day hardening off process.
- The average nighttime low temperature is at least 10C.
When those two pieces are in place, you are ready to transplant your basil plant into the outdoor garden. To do this:
- Dig a hole (either in your raised bed, container, or grow bag)
- Place 1 handful of Worm Castings and 1 tablespoon of 4-4-4 Superfood in the base of that hole. Massage it in.
- Backfill with surrounding soil and gently compact around the stem of the plant so that it is secure.
- Sprinkle 1 handful of Worm Castings and 1 tablespoon of 4-4-4 Superfood on to the surface of the soil and gently massage it into the soil
- Give the plant a deep watering. If using a hose, 30 seconds of spraying and allowing it to soak in is a good amount.
Lastly, given that basil loves such a warm environment, I encourage you to pick up a plastic tote to put over top of it to create a greenhouse environment. This will increase the air temperature by 8-12C - simulating middle of summer temperatures and allowing the basil plant to truly thrive from the beginning of its time in the garden.
DAY 84: BASIL ESTABLISHING INTO OUTDOOR GARDEN
Once you have completed your transplant of your basil plant, you will want to keep a close eye on it and the weather for the following 7-14 days.
The roots have just gone through a fairly traumatic experience with getting transplanted so we don't expect to see too much new growth.
During this period, make sure the temperatures stay warm and that the plant is well watered. The best way to support traumatized roots is with water. To ensure your plant has enough water simply dig down 1-2" into the soil and see if it is moist. If it is not, give it a healthy watering. For grow bags I like to spray the top of the soil for 10 seconds, let it soak in by watering the rest of my grow bags, and then do a second round of 10 seconds. You can make this longer for larger containers and raised beds as the water has more surface area to cover.
As we get to 7 days out from transplanting is when we will start to see the first signs of new growth coming on. When you see these new signs of growth, you will know that the root son your basil plant have successfully adjusted to the garden and it is setup to grow extremely well.
DAY 115: HOW TO HARVEST AND PRESERVE BASIL
You've done it! The beauty of Basil is that once it is established into the garden and the temperatures are consistently warm, it becomes a very low maintenance plant!
For the remainder of the season all that you want to do is continue to prune the plant - and this becomes your on-going harvest. Rather than plucking individual leaves at any point, always prune the stems and take the leaves from that. This will ensure the plant doesn't go to flower and that new foliage growth is put on.
At the end of the season when temperatures begin to cool, you will notice small black spots on the plant and this is a sign that it is beginning to struggle. At this point, pull the plant entirely from the garden and harvest off all the leaves. With this mound of leaves you can do a big round of pesto and then freeze them as individual servings of pesto to enjoy all through the winter!
By following those steps at the key moments through the season you should be setup extremely well to have lush and bountiful basil!
Q: Will basil grow back after winter?
No - Basil is an Annual which means it only grow for one season. As the temperatures cool moving into the Fall, the plant will begin to struggle. At this point, remove all the leaves and process them into a pesto or dry them to preserve them for enjoyment through the winter!
Q: How to fertilize basil?
Start your basil seeds in a Worm Castings Seedling Mix to ensure it has nutrients and microbes from the beginning. At the point of transplanting, amend the soil with both Pure Worm Castings and 4-4-4 Superfood to give it all the nutrients and microbes it needs to thrive as the warmer days of summer approach.
Q: When to grow basil from seed?
This varies depending on your growing zone. You can start Basil inside and you want to hold off on transplanting it until the average night time low temperature is at least 12C. Basil really struggles in cooler weather so don't rush it and use a dome to create a greenhouse environment and keep warmth in for the plant.
Q: What temperature to grow basil?
Basil thrives in a warm environment - and struggles in a cooler environment. For starting the seeds ensure it is at least 20C/70F and for transplanting it ensure that the average night time low temperature is at least 12C before permanently moving it outdoors.
Q: How to grow basil in a pot?
Yes - basil grows well in pots, grow bags, containers, and raised beds. Additionally, because it is a smaller plant you can plant it much more densely. I like to fit 4 Basil plants per square foot.