How to harvest basil seeds (sustainable & saves money)

Harvesting your basil seeds is a great way to introduce succession or successive planting into your herb garden. And basil is an ideal herb if you are new to harvesting seeds.

But there are some pitfalls to be aware of in this seemingly very straightforward process.

Just the facts on how to harvest basil seeds: 
1. Let non-hybrid basil plant flower
2. Allow seed heads to dry
3. Gentry crush seed heads over mesh sieve
4. Collect and store dry seeds in airtight container

If you are growing basil, you most likely already know to prune and top your basil to develop robust, compact, and high-yielding plants.

But today, we are here to tell you to let at least some of your basil plants flower.

5 steps to harvesting basil seeds

We harvest basil seeds to grow more basil, not to eat or use in any other way. It is economical and a more sustainable way to garden.

And it is so easy. You only need to let a few plants flower and go to seed. So whether you grow basil from cuttings or prefer to plant basil seeds in pots and containers, make sure to grow two extra plants this season, and you will have all the basil seeds you need for the next growing season.

1. Let (some of) your basil plants flower

Resist the urge to prune at least some of your basil plants and watch buds develop and turn into basil flowers. And this also means that you need to stop pinching the tops on some of your basil plants.

As the basil flowers mature, the basil leaves develop a bitter taste and become inedible. The plant is now using all its energy to produce flower stalks that will produce those vital basil seeds.

2. Let flower heads wilt and dry

Pick the dried flower heads and petals as they appear – but leave the green carpels to mature and dry.

These green carpels or seed pods will turn brown as the basil seeds mature and are ready to be harvested.

3. Cut flower stalks two inches below the dry seed heads

When the seed pods have turned brown, it is time to harvest and save the basil seeds. Use sharp garden scissors to cut the stalk, as the dried seed pods are fragile and brittle.

4. Gently crush seed heads to harvest seeds

Place stalks on a white paper towel or another soft surface that will provide a contrast to the harvested stalks and dried seed pods.

Use a rolling pin or similar tool to crush pods gently, and then extract and collect seeds.

Use your hands to clean the tiny seeds by removing unwanted pieces of shell, husk, and other plant material. Next, sieve the remaining seed material to be left with only seeds.

5. Store seeds in an airtight container

Ensure the seeds are dry and store them in an airtight container or plastic bag placed in a dark and dry location.

Before storing the seeds, it is advisable to place the container with the seeds in the freezer for 2-4 days to kill off any traces of pest or disease.

When can you harvest basil seeds?

Harvest seeds from mature basil plants after flowering. Basil plants can take 8-16 weeks to develop flowers that will give seeds to harvest.

It is generally easier to harvest basil seeds in the summer as basil needs full sun to grow and develop.

I recommend you use grow lights to grow and harvest basil seeds from indoor plants, especially during the dark months of the year.

Why harvest seeds? I thought basil was a perennial herb.

There are plenty of perennial herbs in and around zone 7, but basil will be grown as an annual herb for most of us.

You can grow basil outdoors, but wait for the last expected frost date to come and go before transplanting basil outdoors.

Basil is not very cold-hardy and does not tolerate frost; why the herb is grown as an annual in most zones, with the possible exception of tropical zones like USDA 11.

Can all varieties of basil seeds be harvested?

Yes, but you should only harvest and save seeds from non-hybrid or open-pollinated varieties if you want to reproduce the actual plant.

Why? Saving basil seed from hybrids is a bit of a lottery as the plant you will grow from the harvested seeds may have vastly different traits than the plant you originally harvested.

Most seed packets from reputable dealers will state if the seeds are non-hybrid, non-GMO, organic, etc.

Now, there is nothing wrong with hybrid or cross pollinated seeds. Hybrids are often developed for desirable traits like being more disease resistant, draught tolerant as well as generally being more high-yielding. But again, the seeds are a lot less likely to reproduce themselves in kind.

We mainly start basil seeds from non-hybrids but also grow some hybrids like Lemon basil and Lime basil. Our favorite varieties of basil are sweet or common basil, Thai basil, cinnamon basil, dark opal basil, and the classic Italian or Genovese basil.

How many seeds do I use to grow a healthy basil plant?

Do not fall for the notion of planting a single majestic seedling in a pot. It may look great in a photo, but you must plant 3-5 seedlings per pot to develop a vigorous and high-yielding plant.

And when growing from seed, use the same logic when you sow your basil seeds. Scatter seeds generously across the pot and be prepared to thin seedlings later as needed.

Saving seeds to save money and more

You need only a few plants to save seeds for an entire growing season. And yes, you will save money.

But as lovely as it is to save money – saving seeds is not really about saving money.

For us, it is about saving money and convenience but also about the satisfaction of creating that same circle of life feeling we talked about when we built our raised garden beds. The same goes for composting and collecting rainwater for our outdoor vegetable gardens.

What about harvesting green seed pods instead?

Yes, but I do not recommend it. You can save basil seeds from green seed pods by using a sharp knife to extract and dry them before storing the seeds. But why rush the process? It makes no sense.

Instead, let the flowers and pods dry on the plant. Allow the seeds to ripen and mature on the plant to give your seeds the best chance to grow when planted. Do not look for shortcuts – mimic nature’s way.

And I find this method to be less work, and it is a great feeling to try and mimic the natural flow of a plant’s life in nature.