Are you ready to start your garden from seeds, but aren't sure where to begin?
Whether you want to plant flowers, vegetables, or herbs, these tips will help you get started with seed starting.
Learn the difference between direct sowing and starting your seeds indoors, and find out what you need to plant seeds at home.
Starting your plants from seeds can be a rewarding experience!
There's nothing quite as satisfying as planting a tiny seed, watching it grow, and then enjoying the rewards of your efforts.
However, it can also be a very frustrating experience, and I don't want you to get discouraged. Here are the basics that you need to know to start your seeds at home.
When we talk about "starting" seeds, it just means planting the seeds.
For example, when we "start" seeds indoors, we plant the seeds and germinate them under ideal conditions to create strong healthy seedlings (a.k.a. transplants).
What Does it Mean to Sow Seeds?
If you’re new to gardening, you might not know what it means to sow a seed. Basically, it just means to plant the seed.
Direct sowing means planting seeds directly into the ground (or container) where it’s going to spend its entire life.
You will always direct sow carrot seeds outside, for example.
Starting seeds indoors refers to the practice of planting a seed in a small vessel and nurturing it until it’s big enough to plant into a bigger vessel or move into its forever home.
Tomato seeds are often started indoors and then transplanted outside once the weather is warm.
🪴 Seed Starting Supplies
If you’re sowing seeds outdoors, all you need is your seeds and the soil you’re going to plant them into. This might be garden soil in your garden beds, or potting soil in your containers.
If you're planting your seeds indoors, you'll need a few supplies. Don't worry, you don't need much to be able to your seeds sucessfully.
Starting off with quality seeds will set you up for success. I recommended buying your seeds from a reputable seed company in your area. I usually buy my seeds online, but you'll often find good brands at nurseries and hardware stores too.
(I bought seeds from Amazon once and it was a HUGE mistake. You have no guarantee of what you're going to get.)
It’s important to know how and when to plant your seeds, and the best way to figure that out is to read the seed packet.
Look for when to start the seeds (i.e. 6 weeks before your last frost), and if they recommend to start the seeds indoors or direct sow them outside.
You should also see if they suggest planting the seed at a certain depth. Large seeds can be planted deeper than small seeds.
If you don’t know your last frost date, you’ll need to get that information first. I have an article on how to find your frost dates and planting zones that you might find helpful.
You can plant your seeds in all kinds of recycled items that you probably already have at home!
Egg trays, yogurt containers, toilet paper rolls and strawberry containers are all popular options for planting seeds. Just be sure to poke a drainage hole into any container that you are planning to plant directly into.
There are also ready-to-use kits that have peat pellets, cow pots or plastic pots (although the plastic pots in those kits tend to be thin and not reusable, so I don't recommend that).
When you’re starting seeds, you don’t want to use garden soil from outside, as it is often too heavy or full of debris (and weeds) for young seedlings to thrive in.
Instead, opt for a good quality seed starting mix. This is essentially a potting mix that has been screened (sifted) to remove any large pieces of rocks, twigs or clumps of soil that might hinder an emerging seed.
If you can’t get seed starting mix, use a colander or strainer from the dollar store to sift potting soil and use that instead.
A good mix is light weight, has no large pieces in it, and drains well.
Access to Light
This is probably the MOST important part of planting seeds. Growing seedlings need a lot of sun – 12 to16 hours worth of it!
If you have a very sunny (probably south-facing) window in your home, that might just do the trick! More often than not though, you’ll find that you have more success if you invest in a grow light.
I usually buy whatever grow lights are on clearance at the end of the season. In my experience, any grow light is better than no grow light, so don't feel like you have to buy the most expensive one on the market.
Don’t be like me an assume that you’ll remember which plant you planted in a certain container. I get lazy and do this with at least a few plants every year, and I always end up with mystery plants because I inevitably move things around and lose track of what's what.
You can use popsicle sticks, wooden labels, plastic labels, or even just use masking tape to labels your containers.
I suggest writing the name of the plant you’re growing and the date that you started the seeds on the tag.
Surprisingly, regular Sharpie’s aren’t all that permanent when it comes to surfaces that get a lot of moisture and light – like plant tags.
Instead, look for an indelible marker that is made for gardening.
Using a heat mat is totally optional, especially if you have a warm place in your home to plant your seeds.
Unfortunately, I have to start my seeds in a cold basement, so a heat mat is necessary to keep my seeds warm enough to germinate.
Humidity Dome (optional)
A humidity dome is a plastic cover (that may or may not have vents) that helps to trap heat and moisture around your seedlings.
Store-bought germination trays will often have a matching humidity dome that you can buy.
Otherwise, improvise by wrapping the top of your seed starting container with plastic wrap, or by using a recycled plastic item that has a lid.
Great options are rotisserie chicken containers, plastic croissant containers or plastic strawberry containers. Simply place smaller containers into one of these larger plastic containers and close the lid.
It’s important to note that the humidity dome should only be used until the seeds germinate, and then removed. Also, venting the lid and occasionally wiping the condensation off of the inside can help reduce the risk of your plants getting mouldy.
Plant Mister and Watering Bottle
Obviously, you are going to need to water your seedlings. At first, you won’t need much water so a plant mister will suffice.
If you don’t have one, you can use an eyedropper or a watering bottle to apply water to the surface of your seeds to keep them moist.
Once your seedlings are a bit bigger, they will need more water than just a fine misting. Use the watering bottle to water the plants from the top, or water them from the bottom if your containers have holes (which is preferred).
When it comes to watering remember that you want to keep your plants moist, but not soaking wet.
This one might seem a bit odd, but adding a fan to your seed starting setup is a great thing to do.
Fans provide a "wind" element that can help prepare your seedlings for life outdoors.
When air moves around seedlings, it causes the plants to sway gently. This gentle movement helps to strengthen the stems of the seedlings, making them more resistant to damage from wind or other environmental stressors. It also allows the lower leaves of the plant to get more light as the plant moves.
Using a fan on your seedlings also increases the air circulation around the plants, and dries out the soil which may help to prevent fungal issues like damping off.
Fans work best at medium to high speeds, and should only be left on during the day.
🏡 How to Plant Seeds Indoors
This is the method that I use to start my seeds indoors. It might look like a lot of steps, but once you get the hang of it you won't even need to look at this list again.
- Disinfect your planting containers by spraying them with 3% food-grade hydrogen peroxide and then let them sit for 10 minutes to dry. Then wash them with warm soapy water, dry well and you're ready to start planting!
- Add your seed starting mix to a large bowl or plastic container.
- Add just enough water to the seed starting mix to saturate it. The soil should be damp - not soaking wet.
- Fill your container with soil, leaving about 1 inch free on top to allow room for watering.
- Label your containers before you plant your seeds.
- Use the tip of a pencil or chopstick to poke holes into the soil. Alternatively, you can buy a dibbler, but it does basically the same thing as the pencil.
- Sow seeds according to the package directions. You will usually want to sow 2-3 seeds per pot, in case one of the seeds doesn’t sprout.
- Cover the seeds lightly with more seed starting mix and mist until damp (again, not soaking wet).
- Cover with plastic wrap (or a humidity dome). This traps the humidity and warmth that the seeds need to germinate.
- Leave containers in a warm place. Some seeds germinate best in the dark, and some seeds need sunlight to germinate, so check the instructions for your particular seeds.
- While you're waiting for the seeds to germinate, be sure to occasionally vent the dome and wipe off excess condensation from the inside. Too much condensation around your seeds can grow mould.
- Once the seeds have sprouted, they will need a ton of light! Remove the plastic, and place under grow lights or by the sunniest window in your home. If you're using a grow light, it needs to be relatively close to the seedlings to prevent them from becoming “leggy” (overly tall with thin stalks).
- Turn your fan on about a week before you want to start hardening them off. Leave the fan on during the day and turn it off with your grow lights at night. The seedlings will dry out more quickly if you use a fan though, so be sure to keep an eye on their moisture levels.
Once your seedlings look like they're getting too big for their containers, and have one or two sets of their true leaves (the leaves that look like the actual plant), pot them up into a larger container, or plant them outside if the weather is warm enough.
Tip: The distance between your lights and your plants will depend on what kind of grow light you have. You can learn more about using grow lights here. I usually just experiment. If my plants look like they're struggling, I move the light down. If my plants look like they're burning, I move it up and then make notes for the following set of seeds that I start.
If you’re planting your seeds outdoors, you’ll follow a similar method. Plant your seeds into the soil outside, cover them with soil and water them. Label each section that you have planted your seeds in and be sure to keep the soil moist while they germinate.
Tips for Planting Small Seeds
Small seeds can be difficult to plant due to their size. '
Try to just dust a small amount of seed starting mix on top of them instead of pushing the seeds down into the mixture. Burying small seeds can prevent them from germinating.
Also, smaller seeds should be started in smaller containers and need to be watered gently to avoid washing them away.
Pro Tip: Sprinkle a light layer of vermiculite on top of your seeds to help prevent damping off.
🙋🏽 Frequently Asked Questions
Generally speaking, most seeds can be started in the Spring, about 6-8 weeks before your average last frost date.
However, it's always best to check your seed packet for the recommended time to start those particular seeds.
Yes, if you have a sunny place in your home that gets light for several hours a day. I do recommend investing in a grow light though, as I find that it gives you better results.
No, most plants need 12-16 hours of light a day. You can turn off the lights at night manually, or set up an automated timer that will turn them off for you.
The depth that you should plant a seed depends on the size and type of seed that you're planting.
You should always refer to the instructions on your seed pack to see what's recommended for the particular seeds you are sowing.
If that information is not available, follow this general rule: the smaller the seed, the more important it is that you don't bury it under a lot of soil.
Tiny seeds should be sown very shallow, and covered with just a light dusting of soil. Larger seeds can be planted at a depth that is two times larger than the width of the seed. When in doubt, err on the side of planting your seeds more shallow than deep.
This article about planting seeds was originally published in 2021. It has since been completely re-written and re-published with new information and photographs.