The Best Way to Start Flower Seeds for a Beautiful Garden

When winter comes around, I don’t know what I would do. But seed sowing gives me something to look forward to! The dark, gloomy days of winter make me dream of warmer weather, and seed sowing is the first step toward making those dreams come true.

This post is going to throw a lot at you. I apologize in advance. It can get pretty complicated to start seeds, even more so than what I’m going to talk about in this post. To keep things simple and avoid making you blank, I’m going to try to stick to the basics. I always tell people to work within their means and set up and to take notes (which I will say again and again!). Just know that the flowers want to grow, so we have that in our favor!.

When to order seeds and why you should be seed starting

Even though seed catalogs don’t start coming in until December or January, I have to say that the seeds I buy from them are usually bought on a whim. When November comes around, most of the seeds we will plant for the next season have already been planned, ordered, and put away in their boxes. We are planning and ordering our seeds once pumpkin spice lattes are back in action. We might not be able to get some varieties or have them in time to plant them on time if we wait until winter. This is especially true for our hardier crops. As a professional flower grower, you are hurting yourself by waiting that long if you order in the winter. It works for hobbyists and some crops. Most of your seed orders should be placed in late summer or early fall. You should refine your plans and buy varieties to fill in gaps or try in the winter, but most of your orders should be placed before then. For this part, you’ll need to get fancy with spreadsheets, but that’s a different story for another day.

Seed starting can seem intimidating but truly, it is one of the most rewarding processes. When you’re in the flower farming business, growing your own plants from seeds is usually the best and most cost-effective way to go. There are some types that might be better ordered as plugs, like lisianthus, because they take so long to grow or need too much special care, taking up valuable space in the propagation house. Some plants, though, won’t grow true from seeds or will make sterile seeds, so cuttings, tubers, or corms are the best ways to start them. But in general, if you want to work on a flower farm, you need to know how to start plants from seeds.

I am going to go through the basics to get you started. Overall, you will need to think like a seed. Learning more about each variety’s specific needs will allow you to better start those varieties from seed. When does the seed usually start to grow? (Hint: you might be able to get some help in the field!) Where does the plant normally grow? When does it bloom? What temperature does it do best in? Does this type of plant do better when planted directly or grown from a transplant?

Seed catalogs and envelopes typically have all this great information. At the end of this post, I also list some books that might be helpful for you, since some seed companies (like Geoseed) send seeds without any information on how to grow them. The best habit to get into is to take notes. Notes on when you planted the seeds, where you chose to grow them, the weather, the date of germination, the date of transplanting, the date of blooming, and so on. Begin to build your own data. This will allow you to see errors or success that you can happily repeat thanks to note taking.

To Direct Sow, to Soil Block or to Start in Trays?

Such a tricky question! “The directions say it should be direct sown, This one says as a transplant. I can’t direct sow or I can’t start indoors. Not only do you have to figure out how to start seeds, but you also have to learn about the different kinds. But the truth is that you will probably do both transplants and direct sowing, even if it’s the same kind of flower, like zinnias! This answer is really going to found in your own means when it’s time to seed start. Certain varieties give the healthiest plants and best blooms if you can direct sow the seed. These are plants that typically have a long taproot and just don’t appreciate it being touched. Some types also germinate and grow so quickly that starting them in trays isn’t necessary or worth the time. For example, sunflowers are best direct sown. They grow quick and prefer not to be transplanted.

We didn’t have much room to direct sow when we had flower farms that were less than 2,000 square feet. Therefore, we started even bachelor buttons in the propagation house. We had to squeeze plants in where and when we could because the beds were always full. We now directly sow everything we can now that we have a bigger farm. This saves us time because we don’t have to plant seeds indoors and then move or bump up the seedlings in the field. When you do direct sowing, you need to make sure you keep the soil moist during dry times. It saves a few steps, materials and some room in our tiny propagation house. Some types of plants we like to direct sow are bachelor buttons, chamomile, bells of Ireland, larkspur, cress, and saponaria. Graham made a cool machine that helps with layout and speeds up seed planting, even when done by hand! We also love how easy it is to use our Jang seeder.

It’s a toss-up between soil blocking and propagation trays. Or maybe you like to use both (like we do!). If you want to learn more about how great soil blocking is, you can read my blog post about it here. We started with soil blocking. With limited funds, buying propagation trays was not in the cards for us. Overtime, we use a little bit of both. Soil blocking can be a tad more time consuming and it does take a lot of soil. A lot of people like to soil block everything, but I’ve found that some plants did better in the trays with loose soil. Instead of making soil blocks, it was faster for me to just put some soil in a tray and plant. I have not completely abandoned the blocks though. If I need to start a variety that doesn’t like having its roots touched but I can’t direct sow in the field because the row isn’t ready, it’s too wet, or something else, I go back to the soil blocks.

First off, it’s not really soil but rather a “substrate. A substrate is what most people mean when they talk about potting soil or seed starting mix in the gardening world. The growing medium. In hydroponics and for starting seeds, soil-less substrate is used. The base is usually made of peat moss or coconut coir. “Soil” is typically referring to being in the earth, planting in the ground. This sounds confusing, right? Try talking about it with a hydroponic grower—they are very picky about the words they use! For example, the starting medium is not soil, even though we call it “potting soil.”

When you are seed starting, you want the starting medium to be light, fluffy with lots of perlite. It will allow the seedling to establish a healthy root system. You want to purchase medium from a reputable company. We are fans of FoxFarm’s Lucky Dog K9 Kube or ProMix HP. Both are great products that in a pinch we can snag locally. As our operation grows, it will be time to haul in the giant sacks from the other side of the mountain. A common medium of many growers is also Sunshine pro-mix, which I have not used personally. It will also be mentioned to use “sterile” seed starting mix that does not have fertilizers. The sterile part is the soil-less base meaning peat moss or coconut coir. To be soil-less is to not have dirt from the garden. Personally, I don’t bother with special “seed starting mix” and have always had great results. The FoxFarm we use does have some nutrients, such as yummy bat guano plus it has mycorrhizae which is excellent for root development. I have had healthy and happy seedlings since using this medium and have not experienced any fertilizer burn or such. You can also make your own seed starting mixes but honestly, I prefer to just buy a commercial potting soil! A mentor told us in the beginning: our time is more valuable than trying to perfect a soil recipe. Just pay the upfront cost and charge accordingly. That same mentor also said “look at what the hemp growers use and follow their lead! They know their stuff!” Seemingly random advice but that advice is solid and has helped us a time or two.

Peat moss is the typical go-to medium for potting soil but more often is being seen as not environmentally friendly. The methodology and the over harvesting from the bogs is not considered sustainable and therefore, making the use of peat moss questionable. Another downside is that peat moss is naturally acidic. The upside is that it is easily attainable and is low cost (at least on the pocketbook). Coconut coir on the other hand is considered a sustainable product and also has a neutral pH which has been particularly favored by hydroponic growers. Pros and cons to both! Deciding on which base to use for your seed starting endeavors is really a heart thing and customizable to your business!

What I want to stress again is that no matter what growing medium you pick, it needs to have a lot of perlite in it. The perlite is what gives the necessary drainage. When people bring me sad seedlings and ask what’s wrong, I usually tell them it’s because of the substrate they used. Often times, it is Miracle Grow or a similar lower quality retail potting soil. Miracle Grow is actually pricey when you look at what you get for that price. You can barely see the perlite and it’s usually coated black. Good substrates won’t cover the perlite in black paint. If the perlite is painted black, the seedlings’ roots will be too! Roots need oxygen and to be able to breathe, so make sure the substrate you choose won’t suffocate them and will also drain well so seedlings don’t drown. When you are using quality potting soil you will actually see lots of perlite on top.

When I first started flower farming, I had no idea what “72s,” “no bigger than 50s,” or “200s” meant.

What the heck were they talking about?!

Cell sizes. Specifically, how many cells made up a 10” X 20” sized tray. The lower the number, the larger the cells.

Choosing the correct propagation tray sizes is important. A 128-size seed would work better for a tiny seed like a snapdragon than a 50-size seed. Why is that? A couple of reasons. Like I said… the seed is tiny. If you put it in a tray that is too big, it might be hard to get the soil to the right temperature for the seed. Also, it saves you room. Shouldn’t it be better if you can plant more seeds in less space? Let’s say you want to grow 128 snapdragons in a row. It would make more sense to have all of those in one tray instead of five. You should also be able to move those snaps from the 128 to the field if you plan everything out right. If the weather or broken equipment messes with that plan, you can always bump up if necessary. A downside to using trays with tiny cells? They dry out quicker, therefore take more diligence in watering.

John Jeavon’s How to Grow More Vegetables was one of my favorite books at the start of this journey. The idea of giving seedlings separate meals was an “aha!” moment for me. You put the seeds in a small pot with soil to start, and as you moved them up, they got new soil and nutrients. This might not be the best for some reasons, but I’ve found that it works well for many of the plants we grow. For example, eucalyptus and tomatoes. I start them in 200s or 288s, and when they get their second set of true leaves, I move them to our deep root trays. This keeps the roots from getting too tight, they don’t seem to mind being moved, and they get the fresh soil and nutrients they need to grow into healthier seedlings for the move without me having to deal with liquid fertilizers when they are so young and weak. I like to give plants like scabiosa and calendula those separate “meals,” but I don’t like to do this with other plants that take longer to grow. ” (Link for this book is provided at the bottom of this post. ).

A good rule of thumb for deciding which tray is appropriate is to look at the seed size. If it is a larger seed, you will need to start them in larger celled trays. For instance, zinnias, cosmos, and calendula have big seeds and grow quickly, so they should be started in 128-cell trays with the smallest cells. However, 72- or 50-cell trays are better. Lisianthus, poppies, and eucalyptus all have small seeds that grow more slowly. For these plants, starting them in 128s or 200s works best because the soil stays warmer, which is what they need to germinate.

After years of using flimsy trays that barely held up to our abuse for a season, we decided to invest in higher quality trays from Bootstrap Farmer. We are slowly building up our stock on these guys and replacing our other ones as they break down. To be honest, I wish I had invested in their trays sooner! Not having to replace trays every season (or mid season!) has actually saved us money along with saving our use in plastic. Our main size trays we start a majority of our seeds in are 128s or 200s , especially our cool-weather loving varieties. The air-pruning 72 tray is one we like especially for ranunculus and anemone corms. The 50s or 72s are needed for our faster growing flowers, rooting cuttings and corms.

Lastly, take notes of what you started in which cells along with were they able to get planted out in time or did you need to bump up or did they become too root-bound? There are some seeds that out the gate I know need deep root cells, such as sweet peas. They need that room for their taproot and they grow fast. They are also one I don’t want to mess around with having to bump up time and time again. As you seed start you will find the trays and sizes that works best for your circumstances.

Some seeds need some special treatment. This is where “thinking like the seed” comes in handy!

Cold stratification is where the seed goes through a cold period, usually for about two to three weeks. Putting the seeds in a cooler or a garage that isn’t heated will make them think it was winter. Larkspur and bells of Ireland are two examples of flowers that germinate best when cold stratified. I have found that if I plant them at the right time of year, they don’t need to be cold-stamped in our climate. If you plant them in the fall, winter, or early spring, our propagation house stays cool enough for them to germinate. I wouldn’t use a heating mat or grow lights to germinate seeds that like to be stratified in cold air.

Physical stratification is where there is a knick or scratch on the seed. Personally, I have not found a seed where this has been a benefit. This is a commonly recommended for tough seeds such as cerinthe.

Soaking is a subtype of physical stratification. Pre-soaking seeds can help to break the hard shell and the idea is that it will promote a quicker germination. This is a common practice for hard seeds such as sweet peas. I have had good success doing this with sweet peas. There are two schools of thought on whether or not to pre-soak sweet peas. I have tried both and personally found more successful germination and less rot with pre-soaking. Peas are another one I like to pre-soak. Not a seed but other crops that needs pre-soaking are ranunculus and anemone corms.

How to start seeds indoors with step by step instructions and demonstrations// Northlawn Flower Farm

FAQ

How do you germinate flower seeds quickly?

Should you soak flower seeds before planting?

Can you just sprinkle flower seeds?

Is it better to start flower seeds indoors or outdoors?

How do you start a plant from seed?

Heat mats placed under the seed starting tray are an excellent way to give the seeds a quick start. Prepare the seed starting medium and container. Choose a commercial seed-starting mix and moisten it well.

How do you start seeds indoors?

To start seeds indoors, you’ll need potting mix, containers to plant your seeds in, and a way to keep them moist. You can start flower seeds in paper cups, toilet paper rolls, paper egg cartons, clear plastic bags, tiny pots, peat pots, or seed-starting trays with a clear lid.

How do you grow flowers from seed?

To grow flowers from seed, fill a planter with a mixture of peat moss, vermiculite, and perlite and sprinkle the seeds on top. Water the seeds, cover the planter in plastic, and put it in a warm location indoors. Once the seeds sprout, thin out the seedlings and plant them outdoors after all danger of frost has passed.

When should I start planting flower seeds indoors?

The best time to start planting flower seeds indoors is about four to eight weeks before the projected outdoor transplant date. This depends on how quickly the plant grows. This information, including whether each flower type is cold hardy or tender to frost, will help growers make this determination.

Should you start your own flower seeds?

Starting your own flower seeds indoors and watching the enchanting process of a seed growing into a flower brings hours of pleasure. It’s a cost-effective hobby that will provide color and beauty to fill your flower boxes, patios, and garden for summertime joy! Why not experiment with starting your own flower seeds right at home!

How do you plant seeds in a pot?

If your seeds are larger (like beans or peas) or they require darkness to germinate (check the instructions on the seed packets), cover them with a layer of vermiculite or seed starting mix equal to their height, usually 1/4 inch to 1/2 inch. Step 4: Label your newly planted seeds. Label each pot.