Growing herbs from seeds can be an addictive pastime. Check out our easy-to-follow guide that has all the important tips you need to know for starting herbs from seed.
Whether you choose to start your herb seeds early indoors or direct sow them in the ground, we’ve got you covered.
For someone with a green thumb who is confined to urban settings, the herb garden may be the answer to your need to watch things grow.
If you have an outdoor garden, that is even better. Growing herbs from seed can fulfill the need to bring forth life from the earth, and add flavor and fragrance to your cooking and your home, as well.
Starting Herbs From Seed – Getting Ready
Starting herbs from seed is not as difficult as some would lead you to believe. You just need some sunlight, small containers, a little potting soil, and a few seeds. Herbs may appear to be fragile, but they are actually quite durable plants.
The first thing to do is choose your seeds. Review the seed packets and locate the following information needed when growing herbs from seed.
- Planting Depth. So you know how deep to plant your seeds.
- Seed Spacing & Thinning Spacing. You may plant your seeds initially six inches apart, then later thin to twelve inches. You will always plant more seeds than you need plants since not every seed will germinate.
- Month to Direct Sow. This will be dependent on your growing region. For example, in the Northeastern United States, you can start basil seeds in May or June, but in the south, they may start the same basil herbs from seed in March or April.
- Mature Size of the Herb Plant. This is important when planning the final layout of your herb garden.
- Other Germination Instructions – such as the number of days it takes for seedlings to emerge or if the seed needs to be started at a certain temperature. Only worry about this if it’s mentioned on the seed packet.
- Date to Start Seeds Indoors. If you are starting seeds indoors – you can begin a few weeks earlier than the direct sow date. Generally, this information will also be on the packet, such as “Start Indoors 4-6 weeks before the last Frost.
- Days to Harvest. This is good information to know – so you can plan other sources of fresh herbs in the meantime if needed.
Use the information on the seed packet to decide where you should plant each type of seed. Draw out your seed plan for your herb garden on a piece of paper. This will help you decide how many seeds of each kind to plant. For example, you may have room for just three larger herb plants in the back of your garden bed, then six medium or smaller-sized herbs in the front.
The next step will be to decide if you will start your seeds indoors or outside in the garden. Starting seeds indoors is a good way to get a jump on the season. If you are direct sowing or planting your seeds outdoors, you can skip ahead to this section -> Planting Herb Seeds Outdoors
How to Grow Herbs From Seed Indoors
Starting seeds indoors is one of my favorite ways to start new plants. The instructions below apply to growing most varieties of herbs. There are some tricks for growing specific varieties, so also be sure to check out our individual guides.
Gather your seed starting supplies below. You will need everything but the grow lights on Day 1. The lights will be required after the seeds germinate (about 7 days for most herbs).
- Seed Starting Mix
- Water (Spray Bottle or Kitchen Sprayer)
- Small Pots
- Plastic Dome
- Grow Lights
To see my specific setups for growing herbs from seed – check out my indoor seed starting supplies list with pictures of how I use each.
To make it even easier, you can use an indoor herb kit which will come with soil, pots, and herb seeds. Then all you need to add is the water and lights.
Step by Step Instructions
- Combine your seed starting mix with water so it is just damp. It’s best to do this in a small tub or bowl to make sure it is moist all the way through.
- Fill small pots with moistened soil about 3/4 to the top. Tap the pots to remove any air pockets.
- Place 2-3 seeds in each pot. Cover with soil to the depth mentioned on the seed packet. For larger seeds you can also make a small hole in the soil with a toothpick or your finger, then cover the seeds with soil.
- Gently pat down the soil for good seed/soil contact. When the seed comes in contact with the moist soil, that gives it the signal to start growing.
- Cover the Pots with a plastic dome (or plastic wrap). This keeps the moisture in and prevents your seeds from drying out.
- Leave the pots covered until you see a single seed germinate.
- As soon as you see the tiny seed break the soil, remove the plastic from all the pots. This gives the new seedling the air it needs to keep growing.
- Place the seeds under lights – position the lights just about an inch above the top of your plants.
- Grow indoors until the seedlings have at least 2 sets of true leaves, raising the lights as the seedlings grow.
- At this point, you may want to transplant the seedlings into larger, individual pots.
- Harden the seeds off by slowly introducing them to the outdoors. (about 2 weeks)
- Transplant into the ground with the recommended spacing for the type of herb you are growing.
For a more detailed step-by-step guide – check out this post: How to Grow Basil From Seed Indoors. You can follow along even if you are growing a different herb variety as most of the steps will be the same.
The Different Types Of Soil Used When Growing Herbs From Seed
The growing medium you use to start your herbs from seed is a critical part of the process. There are different types of soil used for different purposes, and it’s important to know the difference, especially when you are starting herbs from seed.
- Seed starting mix is made for starting herbs from seed indoors.
- Potting mix is used to either transplant your herbs once they get to a certain age or it can also be used in pots or containers inside if you decide to keep your herbs growing indoors.
- Both Potting Soil or Potting Mix can be used for outdoor pots. Note the difference between potting soil and potting mix is typically the amount of compost or perlite included in the bag. A lighter mix should be used for indoor or smaller sized pots. Larger planters can handle a slightly heavier potting soil.
- Garden Soil. Once your herbs are strong enough, you can plant them outdoors in garden soil. This can be purchased at the garden center if needed. You can also blend it with the dirt/soil in the ground to improve it.
- Plain old dirt from the ground should always stay in the ground. Don’t bring it inside or put it in pots.
Why Is Seed Starting Mix Best for Growing Herb Seeds Indoors?
If you are growing herbs from seed indoors, you won’t use soil or dirt at all in your herb pots. You will instead use a seed starting mix that has a very fine consistency for the seeds to sprout and grow roots.
Seed starting mix comes without the extra fertilizers they add to most mixes designed for full-grown plants. Seeds have most of the nutrients they need within the seed shell itself, so they do not require additional fertilizer until they have two sets of true leaves. This works best for almost all seeds. If the seeds are larger, you can also use a regular potting mix in a pinch. Potting mix is a combination of peat, compost, and perlite.
Most experts agree that moisture control potting soil is not a good idea for indoor plants it should also not be used for starting herbs from seed. Since that type of soil is designed to retain water, it could lead to root rot or damping off.
While water retention may be crucial for outdoor plants, indoor plants do not have the same environmental stresses placed on the soil. And when you are starting herbs from seed, it’s actually a good idea to let the seedlings dry out just a little, so it encourages their roots to grow deeper looking for water.
Planting Herb Seeds Outdoors
Planting seeds outdoors is also commonly referred to as direct sowing. Some herbs are easier to grow outdoors such as borage, fennel, or chervil. By the way, if you’ve never tried growing borage from seed, I highly recommend it. The flowers are abundant and so beautiful in the herb or ornamental garden.
Step 1: Amending the Soil (Optional Step)
If you are planting in a garden plot, you may need to amend the soil with compost or peat moss before starting your herbs from seed. Sandy soil will need something added to retain moisture; a heavy, clay soil will need perlite or some other additive to keep it from packing down and strangling the roots.
If your outdoor garden has clay soil that retains too much moisture, you may want to plant in mounds that will allow for better drainage.
If you are unsure what type of soil you have, it is best to simply mix in a well-balanced soil with just a little fertilizer in it, and enough perlite to keep the soil from packing down and becoming hard.
Many herbs are not too fussy about the soil. So you can grow your seeds in your garden soil as it is, then make amendments the following year based on your results.
For Containers: You should never use regular garden soil from the earth in your pots. It tends to pack down and become hard without more vigorous roots, ants, and earthworms to break it up. Use a potting mix instead.
Step 2: Site Preparation For Growing Herbs From Seed
Prepare the soil carefully, raking and crumbling any lumps of soil.
This will help you control the depth of planting, providing for uniform germination.
Think about what would happen if you drop seeds into lumpy soil and cover them up. Some of the seeds will fall into the spaces around the lumps. They may be too deep, and never germinate, or take longer to warm up and germinate, putting that plant behind the others in maturity.
Once you have a smooth planting surface, gently water it. Let the soil soak in the moisture. Then gently rake it again to make sure the soil is “broken up” a little bit.
Step 3: Planting The Herb Seeds In the Ground
Sow the seeds according to the depth recommended on the seed package. Some of them are supposed to be planted only 1/2 inch deep, while others should be left on top of the soil since they need light to germinate.
If you have seeds that require shallow planting (such as 1/4 or 1/8 deep), first sow them where you want them and water them in. The water does two things. First, it softens the seed’s hard shell. Then it helps to ensure the seed has good contact with the soil. Moist contact with the soil plus the warmth from the sun are what “wakes the seed up” so it will sprout.
Once you have watered your seeds in the ground, sprinkle the soil on top, so they are covered to the right depth. This way it is much easier to control the depth of planting.
Always Plant Your Herb Seeds In This Order
- Water when preparing the site.
- Plant the seeds.
- Water the seeds in the ground.
- Cover the seeds to the correct depth.
The reason you cover the seeds last is because you do not want to create a “crust” over the seed.
If you water the ground after covering the seeds, as the soil dries, it will harden making it difficult for the young seedling to break through the top layer.
We want the soil under the seed to stay moist, aiding germination and temperature control. The dry soil on top will warm quickly without getting hard. The seedling can pop easily through this surface, while roots are drawn deeply into the moisture below.
Tip For Growing Very Small Seeds
When starting very tiny herb seeds, be careful not to plant too many seeds close together. To plant tiny herbs seeds evenly, try the following method.
- Place a pinch of seeds in a ¼ cup of sand and shake it up really well. This will create a mixture of sand and seeds that will provide for even planting.
- Sprinkle the mixture across the planting area.
- Pat the sand into your potting mix and the thyme. This will create good seed/soil contact which is important for the seeds to sprout.
- Very tiny seeds like this rarely need to be covered, but check the package instructions just in case.
Just follow these instructions & your seeds will be spaced far enough apart to allow even growth.
Staking Your Herb Plants During Their Growing Cycle
Some herbs will grow so vigorously they require staking. Your inside herb garden may consist only of more modest plants, but outdoors, fennel, for instance, can grow to be 6 feet tall.
When you are growing herbs from seed, they develop a really strong root system, and you can control the growth of stems above the soil. Staking may be necessary later on, so be prepared to push the stake down near the main stem of the plant and support the “trunk.”
If the bushiness of the herb plant seems to get out of control, don’t be shy about trimming it back. Herb plants are designed to be trimmed frequently, and if your pets and pests don’t trim your plants for you, you’ll need to do so.
Growing Herbs From Seed – Watering Tips
Be sure to stay apprised of the moisture and sunlight requirements of your herbs. Some of them, like oregano and thyme, can easily rot if over-watered, while sage needs constant moisture.
For seeds that produce moisture-loving plants, consider forming a basin in the garden, with the seeds in the center. Once the seeds have germinated, you can fill the basin with water and keep the root ball moist.
If the herbs you selected to grow from seed prefer a drier environment, form a mound in the garden, and plant your seeds on the crown of the mound. This will allow the mature plant to grow feeder roots into the surrounding soil for moisture, while the root ball remains safe from drowning.
Finally, a big warning: growing herbs from seeds can be addictive! Gardeners love herbs, because they respond so well to good growing conditions; while providing sturdy, aromatic additions to the garden.