Posted on March 18 2019
After growing lots of flowers from seed for the last few years I’ve learned a lot. I’d love to share a few tips and tricks, so that you don't make the same mistakes I did. I love starting flowers from seed because I have a much larger selection than I would at my local nursery. I like to grow cutting flowers, so that I can bring them inside. Typically a local nursery carries dwarf varieties for borders and beds and for pots. When you grow cutting flowers they need a nice long stem, so big tall plants make up the majority of my garden. Of course you can start seed for any flower you choose.
Where to Buy Seed
I buy most of my seed online from various suppliers. One of my favorites sources is Floretflowers.com Erin carries a lot of beautiful new varieties, as well as tried and true favorites. Most of the seed she carries has a warm modern color palette. She is becoming more and more popular by the minute, so I suggest signing up for her newsletter. That way you'll be notified when the seed is released. If you wait too long for Floret seed, it’s sure to be sold out. Erin also carries a beautiful selection of Dahlia bulbs. They also sell out at lightning speed, so I suggest buying them the day they're released. Some of my other favorite seed suppliers:
I typically only buy flower seed, and vegetable seed that's sown directly in the garden. I buy vegetable starts from a farmers market or a local flower farmer who runs Three Acre Farm.
She sells heirloom vegetable starts, dahlia tubers, and cut flowers at a great price. During certain times of the summer you can visit her garden and cut your own flowers. So if you're local, be sure to pay her a visit this summer.
Mixing Your Own Soil
The first few years of starting seed I was paying a premium price for the “seed starting mix” that was on the shelves next to the seed at my local nursery. After I did the math and realized how much I was spending on fancy dirt, I researched a more affordable option. Now I’ve stopped spending money on the bags inside the store, and I get my supplies outside. When soil is bagged for high quantities, it’s priced much cheaper. Michigan was still very cold this year when I picked up my soil, so I loaded my cart with frozen blocks of soil/ice. The savings however, was totally worth it. I use this same mix for potting soil, so if you're worried that you won't be starting enough seed for all of this soil, you'll be able to use it in pots later in spring. So here's what I use:
½ Bag 1.5 cu ft Vermiculite
1 Bag 2.2 cu ft Peat Moss
1 Bag .75 cu ft Composted Manure
3 Bags .75 cu ft Top Soil
I put it all in my 8 cu ft wheelbarrow and mix it very well. After it’s thawed out, of course.
What I Use to Start Seed and What is Bottom Watering
The most important step I learned in starting flower seed is to bottom water them. Most of the seed is so tiny that the tiniest soil disturbance will prevent the little roots from taking hold, and flowers will not grow. For this reason, you will need two trays. One that’s separated into cells to hold soil, and one underneath that will hold water for “bottom watering”. So instead of watering with a watering can on top of the soil, you will just fill the bottom tray with about a half inch of water. The soil in each cell will absorb the water it needs through the drainage holes. The roots will never be disturbed, and you will have no problem growing flowers. Be sure to keep an eye on the water level, and refill it to ½ inch when it gets low. In a few weeks, and after roots are well established, you may begin watering from the top with a watering can. Your plants will need just enough water to keep the soil moist, not soggy. If your little babies begin to wilt, they need more water. Always give them enough water so that all of the water in each cell has a good soaking, and wait until they need water again. A tiny bit of water in each cell is NOT ENOUGH WATER. I prefer to use plug trays to plant seeds in. They're available in all sorts of sizes and they come in one piece. That way i don't have 10 little trays of four to keep track of. You can find both types of trays on Amazon in packs of 10 here and here. The most economical way to buy trays is through a greenhouse supplier like this one. They have the largest selection of sizes. Be sure your plug trays are the same size as your water tray. I use a 10x20 size for everything.
Where I Found My Grow Lights
I grew all of my flowers last year using two three foot fluorescent lights with grow bulbs. I was lucky enough to find these on Craigslist for a great price. I used to rotate plants underneath the lights. I added three new bulbs to the system this year. The new LED grow bulbs are purple in color. They fit right inside a regular light bulb socket. I found them on Amazon here.
I really like a large plastic plant label. I use the back of the label to write special instructions about each plant. Most of the time, I use it to tell me when to pinch each flat. Some plants like, Zinnia, Snapdragon, and Cosmos will send up two stems if you pinch the flower back. More stems make more flowers. Always make sure there are leaves underneath where you pinch the plant, or you’ll kill it. Snapdragon for instance, need to be pinched when they’re about 4-6”. You pinch them back to about 2”.
How I Sow the Seed
I set my cell flat into my wheelbarrow and fill it with dirt. Then BEFORE I sow any seed I water the soil only with a watering can until it's completely saturated with water. The depth of seed and specific growing directions will be found on the back of each seed packet. Be sure to follow those directions carefully for each type of seed you're planting. The seed packet will also tell you the germination rate of the seed. Most of the flowers I plant have a high germination rate so I only put one seed in each cell. If you are growing a seed with a rate of 70% or below, you may want to sow a few seeds in each cell and thin them later. You thin a seedling by pinching it off with your thumbnail. Dont pull it out or you'll disturb the roots of the plant you're keeping. Once the seed is in each cell I set the plug tray into the water tray under a grow light. I then cover the tray with plastic wrap until the leaves pop up out of the soil. Make sure your room is nice and warm, above 70, so that your seedlings know it's time to come out. There are heating mats that you can set trays on, but they're rather pricey, and not an economical choice for a hobby gardener. I start seeds in my basement so I make sure not to set flats directly onto the floor. I make sure to put them on a skid or a few 2x4s so that the warm air is able to circulate underneath. I heat the room with a space heater to about 75 until my seedlings have a few leaves. Once they are mature enough, I move them out to the greenhouse. I have a little greenhouse heater like this one that keeps the night time temperature above 55. I keep my little babies watered daily until they're ready to go in the garden.