In this second part of my Basic Seed Starting for Beginners series, I walk you through soil, container, lighting, and location options and preparation. I will also teach you how to plan when to plant each seed variety.
“All the flowers of all the tomorrows are in the seeds of today.” –Chinese Proverb
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Hello again! In this 3 part series I will be walking you through the basics of choosing your seeds, gathering your seed starting supplies, preparing your seed starting setup, starting and caring for your seedlings, and basic seed starting troubleshooting. Part 1 was all about how to choose your seeds. In this second part I will show you what steps you need to take to set up your seed starting station. Let’s go through options for basic seed starting materials and figure out when the ideal time is to start your seeds.
While there are seemingly endless options for materials to seed start (and even more opinions), since this is a series geared toward beginning gardeners, I will only be presenting to you the most popular options. If you feel something won’t work for you, there is generally something you can find that will, so don’t give up too easily if you find one option frustrating.
Step 1: Choose your basic seed starting containers
There are 3 components to your basic seed starting container base. The tray, container, and cover.
The trays are meant to keep water and soil from leeching onto the surface of whatever platform your seeds are on.
The containers should be food grade and contain a hole or two on the bottom to allow for extra water drainage. It is also helpful for the bottoms of the containers to be slightly flexible so that you can squeeze to help release the seedlings when transplanting.
The cover should be clear plastic. This creates a mini-greenhouse effect to help your seeds germinate quickly. If you cannot source a hard plastic cover, kitchen plastic wrap will work just fine.
Waterproof Bottom Trays
For your bottom trays you can use anything that is waterproof that will fit your seed starting shelf or platform and fit the containers. These can be old baking sheets, boot trays, large bakery clamshells, or you can purchase seed starting trays here or here.
Large bakery clamshells work for both cover, container, and bottom tray. If you use it as a container, be sure to poke some holes in the bottom for good drainage and put it on another tray.
Seed Starting cell Flats
Pre-packaged seed starting trays with individual cells are by far the easiest option. They usually includes tray, container, and cover. They can be disinfected and reused every year to avoid waste. Some even come with soil pucks like Jiffy Peat Pellets. The downside to these is they will most likely need to be replanted into larger pots before transplanting outside as the container cells tend to be smaller.
Seed Starting pots
Seed starting pots are like cells only they are larger and generally better for seeds that grow larger roots like tomatoes. Starting seeds in pots can help you avoid needing to repot plants if they outgrow their cells. These can be reused used year after year as well.
Egg cartons and biodegradable containers
Peat pots and egg cartons are generally cheap, biodegradable, and easy to transplant since you usually can just plant it with the pot. These can be placed into a bakery clamshell or set on a cookie sheet covered with plastic wrap. The downside to these is they tend to dry out quickly and in the process of trying to keep everything watered they can fall apart over time from water saturation.
Reuse old plant containers
This is probably one the most popular. Anytime you buy a seedling from the store you have the plastic container leftover. Don’t throw them away! Reuse them! These are perfectly sized to seed start and rarely do you need to replant seedlings to larger pots in these cases. The only downside is that you will need to disinfect them (and any other reused seed starting container) every year.
Disinfecting used containers
To disinfect them, wash them out with dish soap and water or vinegar. Then soak them for at least 10 minutes in a 9 parts hot water to 1 part bleach solution. You can also spray them with hydrogen peroxide and let them sit for 10 minutes instead.
Step 2: Consider Watering Options
Watering from above is not ideal for basic seed starting and seedlings. They are so delicate and the seeds are often so light that simply pouring water over the top of them can drown your small seedlings, or wash the seeds out of the soil, before they even get a chance to germinate. Most seeds start out sitting barely on the surface of the soil, so in order for them to germinate the best watering method to start with is a spray bottle.
This is a necessity at least until the seed roots grow a little deeper into the soil. Make sure whatever spray bottle you get has a spray setting and doesn’t just stream.
If you choose a container that is deep enough with containers that have holes in the bottom then bottom watering after the seedlings have developed deeper roots is an excellent way to keep the seedlings watered. If you cannot bottom water than you will need to use your spray bottle to water until the seedlings have grown to a couple inches. Consider how you want to water when choosing your containers and bottom trays.
Step 3: Choose your soil
Your soil choice is very important to the success of your plants. Using any old potting soil can affect whether the seeds can germinate well or whether they grow white fuzzy mold and dampen off before they are even an inch tall. Damping off is a disease usually caused by fungus and mold that can kill your entire tray of seedlings. It is usually recommended to use a soil that has been sterilized for this reason.
Sphagnum peat moss
Sphagnum moss is the decomposed plant matter of sphagnum moss. This is dried and sterilized and sold as a great seed starting medium. It is lightweight, can hold water extremely well, and is great for helping sandy soil.
Peat Pellets are just compressed peat that expands when watered to create a container-like soil block. These are a less-mess approach to seed starting and can be great for plants that don’t like transplanting if the larger ones are used. The smaller ones may need to be transferred to larger pots before transplanting just like cell containers. Peat pellets can help take the guesswork out of picking your soil.
Perlite is a volcanic ash. It is very, very light and is great for drainage and maintaining cool soil temperature. This is usually used in a combination with other soils for seed starting.
Vermiculite is expanded mica. It holds water extremely well and contains vital nutrients for root growth. This is also usually used in a combination with other soils for seed starting.
Seed Starting mix
Seed staring mix takes the guesswork out of mixing together different soils. It usually is composed of certain amounts of perlite, vermiculite, and/or sphagnum peat moss. This is a great option for beginner gardeners. One thing to remember though is that seed starting mix is only meant to have enough nutrients to help the seed germinate until it has its first set of true leaves (one additional set besides the initial baby leaves). After that the seedlings should be replanted into a potting soil.
Potting soil is just what it says. It is soil meant for pots. It contains vital nutrients and maintains water and temperature well. Once seeds germinate and have their first set of true leaves it is a good idea to move them to potting soil in larger containers if you cannot yet transplant them outside.
Many gardeners opt to skip the seed starting mix and start their seeds straight in potting soil. This is usually fine but keep in mind you may need to sift out the larger soil matter from your potting soil as this is not ideal for seeds starting. Potting soil is also not sterilized so you may have a higher risk of damping off.
Soil from your garden
Many wonder if you can just use soil straight from your garden. This is not recommended. Garden soil may have nutrient deficiencies as well as pests and disease that young seedlings cannot withstand. Garden soil may be sterilized at home with an oven, but that is generally considered too much hassle for most people.
Step 3: Choose Your location
When deciding where to put your seed starting setup, there are a few things you need to consider. Make sure the setup will be out of the way of pets and young children. I learned really quickly not to put my plants in the windowsill that my cat likes to sit on…
Also consider the temperature of the area. A garage may not be ideal if it is not insulated as many plants prefer warm soil temperatures to germinate. If you must use your garage, consider keeping them inside just until they germinate and then moving them out to the garage onto a heat mat.
Seed Starting Heat Mats
Heat mats are mats specially designed for starting seeds. These do not get extremely hot and many you can set to the temperature that you would like the soil to be for the particular seeds you are starting (the ideal soil temperature would be listed on the seed packet). I would recommend using these if you are seed starting in a cold garage or colder area.
Most people do not have a sunny enough window to start seeds in without them becoming too leggy (tall and spindly). If plants are leggy it means they are having to reach to get adequate sunlight. A sunny window can work if it is south facing and gets sunlight through most of the day. Beware of plants getting too cold at night by the window.
Shelving with lighting
This is the easiest option for most people. Setting up a light to hand on shelves or over a table is the best way to create ideal conditions for you seed starting setup. You can get wire shelving that makes for easy light hanging as well. This can be moved to anywhere that is convenient.
Step 4: Choose Your lighting
The lighting for seed starting is where a lot of people get stuck. There are so many options for lighting but it is a lot less complicated than it may seem.
hanging Grow lights
Grow lights are often what people think they need for seed starting and buying these definitely takes the guesswork out of lighting but they can be confusing too. These are specially made fixtures specifically for growing plants indoors and can have a variety of settings for brightness, timing, and spectrum. They tend to be cost prohibitive for some people and are really only necessary of you intend to grow plants past the seedling stage.
Beware when ordering grow lights online as the size can be much smaller than expected (yes–I made that mistake).
These are very popular for seed starting because they are widely available and very cost effective. You can only use shop lights for the seedling stage. If you want to grow your plant to maturity you would need grow lights. Also, beware shop lights can sometimes get too hot for some seedlings depending on the light but otherwise these are a great and very popular option.
Step 5: Schedule your seed starting dates
Seeds are not started all at once. Contrary to popular belief, the time when you start your seeds doesn’t have to do with your gardening zone. The time you start the seed depends on the type of plant, plant variety, and, most importantly, your first and last frost dates.
First and Last Frost Dates
Your first and last frost dates are the dates all of your seed starting and planting will revolve around. these are very important dates! You last frost date is the average date that your area has it’s last hard frost for the winter. For my zip code, this is around May 2nd. Now we can have our last frost before then or after then but that is the average date.
When it comes to your first frost date, that is the average first hard freeze your area gets in the fall. This date is important when it comes to harvesting or planning a garden for the fall.
For our seed starting purposes we will focus on our Spring last frost dates. You can figure out your first and last frost date by entering your zip code here.
Basic guidelines for seed starting Dates
When figuring out when to start seeds, you will look at the back of your seed packet. It will tell you to start indoors a number of weeks before your last frost date. Take you last frost date and count back that number of weeks on a calendar. That is where you will write in the date you need to start those specific seeds.
If you don’t have that information on the seed packet, there are some rules of thumb you can follow.
- Onions, leeks, eggplant, and celery as early as 10 to 12 weeks before your last frost date.
- Tomatoes and peppers 8 weeks before last average frost date
- Melons, and lettuces 4 weeks before last average frost date
Here is a summary of supplies you need. You can find links to these supplies in the “SHOP THIS POST” section below.
- Seeds (we like True Leaf Market)
- Spray Bottle or bottom watering trays
- Bottom Trays, baking sheets, or boot trays
- Clear top covers
- Soil of choice
- Seed Containers
- Seedling labels
- Heat Mats
We’re almost there folks! You are now ready to start you seeds! Stay tuned for the 3rd and final part in our Basic Seed Starting for Beginners series! Leave me a comment and let me know how excited you are to start your seeds.