Growing herbs from seed 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.
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. 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 Importance Of Soil 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.
Soil Selection When Starting Herbs From Seed
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.
Growing Herbs From Seed – Amending The Soil
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 you are unsure, it is best to simply use a well-balanced soil with just a little fertilizer in it, and enough perlite to keep the soil from packing down and becoming hard.
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.
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.
Soil 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.
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.
The reason you water first, plant, and then cover the seeds is because you do not want to create a “crust” over the seed. As the soil dries, it will harden. However, the moist soil under the seed will remain moist, aiding germination and temperature control, and 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.