Seed Starting Guide

It’s that time of year again. We’ve made it through the darkest days of winter and the thought of spring is on the horizon.  Excitement is building at the thought of a fresh new season and I’m absolutely itching to get my hands in the dirt. 

Although it’s not quite time to spend the days in the flower field just yet, it is time to get things growing. And that means it’s time to start some seeds! 

February through March is the ideal time to start and plant seeds that are considered hardy annuals. These include larkspur, feverfew and snapdragons to name a few. You can find a complete list of my favorite hardy annuals that we grow at Hidden Springs here, along with my recommended varieties and tips for harvest. 

By the end of March I’m switching gears to think about the warm season annuals. Flowers like cosmos, basil, celosia and amaranth that go into the ground after our last frost date need to be started 6 to 8 weeks ahead, which means that March is go-time for serious seed starting.  

With seed starting season at hand, I’ve rounded up a short list of resources, supplies and guides that will get you going. Whether you’re a newbie or just want a refresher on seed starting basics, I hope that you’ll find this a helpful guide! 

SEED STARTING: FIRST STEPS

1. Select a location. You can start seeds just about anywhere, but I recommend a basement or spare room where your seedlings can grow, undisturbed by little hands or curious pets. Measure the space for your table or shelving unit and be sure you have a power outlet nearby. This area can get a little messy (or very messy in my case) so you might want to consider mats or plastic covering to protect the floor, or use a space that can be swept and cleaned up easily. 

2. Make a plan. Peruse seed catalogs, websites and social media for inspiration and create a list of flowers you plan to grow this year. (You can get my free list of Top Cut Flowers for Beginners here!) Once you’ve purchased seeds, make notes on when and how each variety should be started. I use a spreadsheet to track the seeds I have to start each week, the quantity and when they’ll go into the ground. Make sure you know whether the seed requires light to germinate and preferred temperatures. Not all seeds like the heat mat! 

3. Purchase seeds. While you can find flower seeds at just about any home and garden store, they don’t always carry the best varieties for cut flowers. You should also consider the price per seed; usually the best prices come in larger quanitites. Try Johnny’s Seeds and The Gardener’s Workshop. 

4. Map out your garden. Now that you’ve planned for starting the seeds it’s important to think about where they’re going to go once they’ve sprouted. Before the seedlings are ready to plant, map out your garden or flower field. Be sure to account for the spacing needed for each type of flower and prepare the soil for planting. Spacing information and other helpful information can usually be found on the back of the seed pack. 

SEED STARTING: SUPPLIES

It’s time to get started on creating your seed starting room/corner/nook. You don’t actually need a bunch of expensive equipment to get started. Most of what I use can be found at the local hardware store or ordered online. I’ve rounded up a lot of my seed starting gear in my Amazon shop. 

To get started you’ll need:

Shelving & Lights. I use a 5-tier metal shelving unit and two sets of shop lights per shelf. Rather than spending lots of money on expensive grow lights, create your own by pairing one cool bulb and one warm to mimic the spectrum of natural sunlight. We use metal chains and s-hooks to suspend the lights on each shelf. Make sure they’re adjustable so you can move them as your plants grow! I plug all of the lights into a power strip and the power strip into a timer, so they’re on for about 16 hours per day and off for 8. 

Heat Mats. Most seeds like warm soil temps to germinate and that’s where heat mats come in. They’re like a heating pad for the baby plants and keep the soil temperature warmer than the air. They come in multiple sizes but I like the large size that takes up an entire shelf. This allows me to start multiple trays at once before bumping them all to the next tier. 

Cells, Trays & Domes. When you think seed starting you probably think of the cell packs but the trays and domes are equally essential. The cell trays will hold the soil and seed/plant, while the flat trays are helpful for bottom watering and the clear plastic domes retain moisture for the tender seedlings. If you’re not into all of the plastic trays you can also use the soil blocking method. I prefer the trays as they’re more forgiving of an occasional missed watering, but I’ve tried the soil block method too. Here’s the blocker that I use. 

Soil & Fertilizer. Make sure you’re using a good quality seed starting mix as opposed to standard potting soil. Seed starting medium is light and fluffy, perfect for small roots to emerge. Once the seedlings have established I use Neptune’s Harvest about once a week to give them a little boost of nutrients. A sprayer is helpful for fertilizer application as well as watering before plants are established. 

Labels. As you finish each tray of seeds, be sure to label the type of plant and variety or color. Trust me, you won’t remember later, especially if you’re starting thousands of seeds. I use these plastic plant tags and reuse them as many times as possible. You can also use painter’s tape or popsicle sticks to label your trays. 

SEED STARTING: HOW TO

You’ve got a plan, your supplies are on hand. All that’s left to do is start the seeds! Here’s a basic rundown of the steps to starting your own seedlings. 

1. Fill seed trays with damp seed starting mix. Either use a large plastic tub to moisten a lot of soil at once before filling, or fill the trays and set them in water to soak until they’re damp. 
2. Sow seeds into the soil according to the recommendations on the seed packet. Some seeds need light to germinate; in this case, you’ll just gently press them into the soil to maintain contact until they sprout. Other seeds require darkness; in this case, push them down into the soil and lightly cover with additional seed starting mix or vermiculite. 
3. Place a clear plastic dome over the tray to maintain moisture and protect from potential critters and set the entire tray onto the heat mat, if heat is needed for germination. 
4. Over the next several days, monitor the tray carefully for signs of sprouts. Check on the soil and be sure it’s not completely dry. Bottom water seed trays as needed or use a small sprayer to mist the surface of the soil. Your seed packets should note the time to germination; some plants take longer than others. 
5. As soon as plants have emerged, remove the humidity dome and be sure that the tray is about 2 inches away from the lights. Yes, 2 inches! If seedlings do not have adequate light they will stretch and lengthen, becoming leggy and unhealthy. 
6. As the plants grow, adjust the hanging lights to maintain about 2 inches between the top of the seedlings and the lights. Again, you might want to use a timer to be sure that your plants are getting enough light. I aim for 16 hours of light and 8 hours of dark. Make sure that the soil is moist but not soaking wet and add fertilizer about once per week. 
7. Following the directions on the seed packet, when the seedlings have grown enough to go out in the field, begin the process of hardening off. Slowly transition them to the climate, sun, and elements, otherwise, they will experience shock when planted. I harden off seedlings for about a week before planting. 

SEED STARTING: RESOURCES

There’s a lot to learn about seed starting and I truly believe that trial and error is the best teacher, but it’s helpful to have some resources to rely on. Here are a few I recommend: 

• The Gardener’s Workshop (lots of online workshops!)
• The Flower Farmer by Lynn Byczynski
• Cool Flowers by Lisa Mason Ziegler
• Cut Flower Garden by Erin Benzakein

I've rounded up most of my seed starting essentials on my Amazon Shop (and most are linked here in this post), but you will likely find most of these items in your local garden supply store. I always recommend shopping locally before turning to Amazon! 

And a final parting word on seed starting: remember that everyone starts somewhere! You’re likely to have just as many failures as successes but try to think of each failure as a learning opportunity. I’m five years into this flower farming thing and I still lose several trays of seedlings per season. Try not to get discouraged. Take notes and try something new next time. 

I’m wishing you success and lots of green as you begin your seed starting journey! 

PS... my next flower farm coaching group starts on March 4. If you're ready to get serious about your flower business this year and get 'In the Weeds' of flower farming, tap here to be the first to know when the group opens for enrollment! 

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