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Grow Like a Pro: Seed Starting for Beginners
There is something so incredibly rewarding about watching a little seed sprout into a seedling and grow into a big, fruitful plant. Not unlike to watching your own children grow – it’s seriously the best.
I’ve learned a lot about seed starting over the years, mostly from trial and error, and by killing my fair share of seedlings. Death by underwatering, overwatering, freezing, forgetfulness, carelessness, or curious experimentation has been the fate of many of my seeds.
It can be super disheartening to see hours of your hard work go down the drain simply because you didn’t provide enough water in those early weeks of germination or harden off your seedlings properly.
To be honest, trial and error — though valuable in experience — isn’t the most fun or fast way to learn when it comes to seed starting. So, I’ve assembled the ultimate roundup below of my best tips, tricks, and hacks to help you succeed this growing season.
Good planning is key to a successful garden.
Click HERE to check out my garden planning post – all the ins and outs of getting started!
Why Start From Seed?
There are a few reasons to start your garden from seed! Number one, it’s MUCH cheaper than buying plants. For around $3 you can purchase a seed packet of 50 seeds, aka 50 plants if they grow successfully. You would pay the same price (or sometimes a bit more) for ONE plant if you decide not to grow from seed. As you can see, the savings is crazy!
I would also start from seed if you plan on growing A LOT. If you’re only thinking you need a few tomato plants, a couple pepper plants, a few other here and there, it might be easier to just buy the veggie starts when they come to market in April/May. But if you’re going all in and have a big garden planned, the savings would be huge if you could start from seed!
Lastly, as I said above, it’s super rewarding and fascinating to watch your little plant babies grow big and fruitful. And if you have older kids, it’s a great opportunity to teach them about where food comes from!
- High-quality seeds (click here for a list of my favorite seed suppliers)
- Seed Starting Guide & Garden Planner (free printable below)
- Seed Starting Potting Mix
- Cell packs & trays or my personal favorite, a soil blocker (more on this here and here)
- Clear humidity domes
- Dibbler or pencil
- Seed dispenser or toothpick (optional for tiny seeds)
- Plant tags and a sharpie
- Lighting (see the very last section of this post for an easy lighting DIY!)
- Heat mats (depending on individual seed germination requirements)
Scroll down for my step by step how-to for seed starting! If you’re ready to move on from seed starting, check out these posts next! How to Map, Plan & Plant Your Veggie Garden and 7 Early Spring Garden Tasks
UPDATE FOR 2022:
What about biodegradable seedling pots?
I tried this trend last season and long story short, it was a bust.
Yes, starting seeds in biodegradable cups are great in theory, but it really depends on the thickness and how long they take to degrade. If the “plantable” container is still intact when planted out, and hasn’t broken down by the time the roots reach its edge and want to grow beyond, the container will constrict them and limit growth.
On the other hand, some are too flimsy and could degrade too quickly (like toilet paper rolls). They may fall apart while you’re still tending to them inside, making a mess or even damaging seedlings. Also, many biodegradable pots are made from peat, which receives some criticism for being not very sustainable. They’re also a single-use product. Some people love them though, and no judgment if you do! Whatever works for you, this has just been my personal experience!
If you are into growing seeds in a more sustainable way, scroll down to my section on soil blocking!
Seed Starting Basics
1. Choose The Right Seeds. Before you get started it’s important to choose the right seeds for YOU. First, think about which veggies your family eats the most or which flowers you enjoy the most. You’ll want to be growing foods you will actually eat and flowers you will actually enjoy!
Also, I have to mention, please don’t buy your seeds from third party retailers like Amazon, seeds are one thing you absolutely have to go to the primary source on if you want the best quality guaranteed!
2. Know Your Hardiness Zone & last frost date. This is super important to know before you plan your garden because it determines your seeding and planting schedule. You wouldn’t want to plant the wrong plant outside too early and risk your seedlings freezing to death! For my zone, our last frost date (the date after which the threat of frost is 0%) is right around Mother’s Day. Check this site RIGHT HERE to check what hardiness zone you’re in and your specific seeding date recommendations. CLICK HERE for more information about frost dates (Farmer’s Almanac). I’ve also included a handy frost free dates chart below, you just have to know your zone!
CLICK HERE to find your USDA Hardiness Zone.
3. Figure Out the Sow and Transplant Dates of Each Seed. Read the backs of your seed packets!! So much information lies right there in your hands! The back of the seed package provides instructions on when to sow your seeds indoors and when to transplant the seedlings into the garden. You can also reference my free download – Seed Starting Guide for Veggies, Herbs, and Flowers (just below).
4. Set Up a Chart. I use a super simple spreadsheet but it keeps me organized! I’ve created a free downloadable guide, enter your email in the box above to scoop it up!
Approximate Frost Free Dates by Zone
|Zone||Last Frost Date||First Frost Date|
|1||July 16-31||August 1-15|
|2||June 8-21||September 8-21|
|3||May 8-21||September 21-October 7|
|4||May 22-June 7||October 1-15|
|5||May 1-15||October 8-21|
|6||April 16-30||October 16-31|
|7||April 1-15||October 21-November 7|
|8||March 16-30||November 1-15|
|9||February 16-28||December 1-15|
|10-13||No freeze||No freeze|
Easiest Seeds for Beginners
You can, of course, try any seeds you’d like – which I totally encourage – but because I am frequently asked, I’ve listed my favorite and easiest seeds for beginners to try. Again, I recommend following the info and instructions closely on each individual seed packet but I go over my general method below. One important thing to note about seed starting is the importance of soil temperature – read more about that HERE.
Vegetables: Brassica Family
Includes veggies like broccoli, cauliflower, brussel sprouts, kale, and cabbage. This family of plants loves the cold weather and germinates in cooler soil. You can start seeds inside in late winter or direct sow into the ground in early Spring, as soon as soil is workable, because the plants can tolerate a frost or light freeze. We direct sow in the Spring!
Vegetables: Root Veggies
For root crops like carrots, beets, kohlrabi, radishes, and parsnips, it’s best to direct sow outside (in the early Spring) so their delicate taproot doesn’t have to be transplanted and so it has ample room to grow deep. Because they grow under the soil it is optimal to have smooth, loose soil (not rocky or compacted), otherwise, they will have great difficulty forming correctly. You can also grow these veggies successfully in containers, just make sure to get ones that are deep enough (12-14″ deep is best)!
Greens like Swiss Chard, lettuces, spinach, and arugula are super easy to start from seed and also prefer cooler temps and cooler soil. Similar to the Brassica family, these seeds can be started indoors in late winter and transplanted out during early Spring, or direct-sown outside during early Spring. I especially love the “cut and come again” lettuces and rainbow chard.
Vegetables: Nightshade Family
Tomatoes, eggplant, peppers. Start indoors, these seeds/plants prefer warm soil and cannot be planted outside until the ground has warmed (two weeks AFTER your last frost date). For my zone (6) we plant these out on Memorial Day weekend.
Beans, cucumber, squash/zucchini/pumpkin, watermelon, cantaloupe and the like all love the warm weather and warm soil. They do well either seeded indoors one month before the last frost date, or when direct seeded into the ground after the threat of frost is over (for me that’s mid-late May). They take a couple weeks to get going, but with the right care, these plants take off like crazy and can be hard to tame. Make sure you have proper trellising and ample space for them to spread!
Many herbs are actually propagated from cuttings (sage, rosemary, thyme) so you’re better off buying the plants instead of propagating them yourself. The easier herbs to start from seed are basil, parsley, cilantro, lemon balm, and oregano. Basil and lemon balm like it warm so their seeding schedule is similar to the nightshade family schedule. The others can tolerate cooler temps and can be seeded indoors in late winter and planted outside by mid-May.
My favorite cut flowers are listed below, these flowers have been relatively easy to start from seed in my experience.
- Sweet Peas
- Dahlia (tuber)
Seed Starting: Variables to Consider
Before I dive into my methods I wanted to list some questions to consider. These are some of the variables that differ between seed varieties, so best practice is learning what specifics your seeds require and adjust accordingly.
Most of the answers to these questions will be found on the individual seed packet, or go back to the reputable site you bought the seeds from! DO NOT buy seeds from a third party like Amazon, you have no idea what you’re really getting and if the seeds are even fresh, yikes! Stick with the reputable guys.
- How long to germination?
- How deep to plant?
- What container is best to start them in?
- Can they be sowed directly into the ground or will they do better if started indoors?
- Special soil requirements they will do best in?
- Are there light requirements for germination or is complete darkness needed?
- When can seedlings be planted outside? (know your hardiness zone and last frost date, this will determine how far in advance you plant your seeds indoors, most take right around 6 weeks to get going so you count backwards from your last frost date.)
Seed Starting in Cell Packs
1. Gather all the supplies from the supplies list (seedling mix substrate, seed trays, dome lids, plant tags, SEEDS, etc.).
2. Before you fill your trays with soil (seed starting mix), moisten it until it is thoroughly damp but not soaking wet. This makes it easier to work with and you won’t have to water as much once the seeds are in their new home.
3. Fill your cell packs to the top with soil, tap them so they settle and so no air pockets are left but DO NOT pack down. You want the soil to be workable.
4. Label – I like to label BEFORE I plant just in case I forget what I’m planting. Haha. But really, I do feel like it’s helpful! I write the plant name, variety, and date on wooden tags like these.
5. PLANTING DEPTH & LIGHT: Make holes in each cell using your finger, a pencil or a dibbler. The general rule of thumb is to plant the seed twice as deep as it is wide (diameter). However, be sure to always reference your individual seed packets for this specific info. Some will require darkness to germinate and should be covered while some require light and will germinate better sitting right on the soil surface!
6. Drop 2-3 seeds in each hole until the entire tray is full. If you have super tiny seeds (like Snapdragon) I suggest licking the tip of a toothpick and picking them up that way, it works! Multiple seeds gives you a higher success rate since there are always some seeds that won’t germinate, you will thin the seedlings later!
7. Cover the tray with a light dusting of vermiculite making sure all cells are covered.
8. WATERING: For new sowings and fragile seedlings I find bottom watering is best initially. Place the seeded trays in a shallow tray filled with about an inch of water. Allowing the seeds to soak up the water from below (versus overhead watering with a hose) is a much more delicate way for them to drink, this way nothing gets shifted out of place, or washed away, by a forceful hose.
9. Remove trays from water once the soil surface is evenly moist. Seed trays should not be watered from overhead until the plants have their first set of true leaves (which is their second set of actual leaves). Again, one strong blast from the hose will wash tiny seeds or seedlings right away. Alternatively, you can use a spray bottle to mist from overhead but even this can be too forceful.
10. TEMPERATURE: Again, reference your seed packet for the exact requirements of your specific seeds! Some prefer to germinate at cool temperatures and some prefer it warm. If your seeds like it warm cover the trays with a clear plastic dome or plastic wrap and set in a warm corner of the house (consistent temps of above 65 degrees) or onto a heat mat set to 70 degrees. Some seeds also require light to germinate but most are fine without light until you see the sprouts pop up.
I’m not going to go into a ton here, hopefully this year I can dedicate a blog post to it, I have become a HUGE fan!! For now here are some benefits I’ve found of soil blocking:
🌱 less space needed
🌱 grow amazing + healthy plants
🌱 strong root systems
🌱 less transplant shock
🌱 no waste or storage issues
Checking on and Maintaining Your Seedlings’ Health
In no time your little plant babies will be ready to live outside! Follow these steps to make sure they are healthy and strong enough and ready to be planted out in the garden. When you are ready to do that (or a bit before!) check out my blog post — all about mapping, planning and planting out your garden!
1. Light. Check trays daily, and once seeds have sprouted, remove plastic dome lids or plastic wrap, remove the heat mat if you used one, and move to a bright space such as a greenhouse or under fluorescent lights (I found an awesome DIY lighting tutorial HERE). If using lights, make sure that they are suspended a few inches above seedlings and put them on a timer, making sure to give plants 14-16 hours of light per day. As the plants get taller, be sure to keep raising the lights so that they are 2-3 inches above the tallest plant.
2. Water & Feed. Check seedlings daily and water (either from underneath or via misting) when the soil appears dry. I also love this watering can, it has the most delicate and fine water stream that is perfect for young plants! As young plants grow, they need to be fed. Following the label instructions, add the correct amount of liquid seaweed and fish emulsion to your watering can and drench plants weekly.
3. Thinning. Thin extra seedlings about 3-4 weeks after sowing and when the plants are established (two sets of leaves). This is survival of the fittest, using your mini snips (or other pruners with a super fine point), cut away the slower-growing/not as strong seedlings so the bigger ones can thrive. Do not pull out these unwanted seedlings as disturbing the root systems can affect nearby plants, just cut them down to the soil surface.
Almost ready for their big debut!
4. Repot. When seedlings outgrow their trays, either repot them into larger containers or if the weather is warm enough, start transitioning them outside to “harden off.”
5. Hardening Off. The second to last step is hardening off your seedlings. We start this about 2 weeks before their transplant date. Hardening off is the process of adapting plants to the outside so they can adjust to sunlight, fluctuating temps, and less frequent watering. Set trays in a sheltered spot outside, increasing the amount of time they are out by an hour or so each day. Start with 2-3 hours/day and increase from there.
6. Transplant Outside. Some cold-weather loving plants can be transplanted out before the last frost date of your zone (think spinach and broccoli and hardy cut flower annuals) but for most you will plant outside in the garden once all danger of frost has passed. For myplanting tips check out this post for my 5 Biggest Tips for Planting Your Garden!
PHEW! I know it might feel like there is a lot to know about seed starting (I mean, there is haha, you could literally read entire books on it), but the main thing to remember is to JUST DO IT! When it comes to gardening nothing beats learning as you go and experiencing it for yourself!
I hope my advice was helpful and can at least help get you started, I’d love to know what you’re planning this year for your garden!
Further Reading on Seed Starting & Planting
National Garden Association – Great all-around and interactive resource for gardeners
USDA Plant Database – tons of info on specific plants
NYBG – Great resource but also an amazing place to visit if you are in the tri-state area!
Missouri Botanical Garden – Incredible database of plant info
Cornell Cooperative Extension – Great resource for anyone in NY, but still helpful if you are elsewhere
Farmer’s Almanac – Because this has been referenced by farmers and gardeners for hundreds of years and it’s still the best
Association of Specialty Cut Flower Growers – Tons of info and cutting edge research from this group
Botanical Interests – High quality, heirloom seeds & supplies
Renee’s Garden – My favorite for veggie & herb seeds
Johnny’s Seeds – High quality seeds, large quantities
Eden Brothers – Great resource for ALL seeds, tubers and bulbs – where I get my dahlia tubers
Floret Flower Farm – Gorgeous and unique selection of flower seeds and she has a fantastic blog filled with growing info!
Longfield Gardens – Great selection of dahlia tubers
Five Forks Farm – Small farm out of MA, really unique dahlia varieties, tuber order time is January and they sell quickly!
The Flower Hat – Small farm out of MT, really unique dahlia, ranunculus and anemone varieties!
Looking for more gardening posts? Check these out!
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