How To Start Wildflower Seeds Indoors

• You can control the environment of your seed germination by maintaining a certain temperature, keeping the trays in a sunny spot, and covering them to help with humidity and warmth.
• You can get a jumpstart on the growing season! This is helpful in colder areas where the growing season is short. Instead of planting your seeds directly in the soil at the end of May, you can transplant already-established seedlings at the same time and enjoy blooms that much earlier. This is also the secret behind growing plants that require a longer season than your climate can give them.
• You can utilize succession planting. If you’re growing varieties like Zinnias and want a longer bloom period, if you start some weeks before planting time and then direct sow more seeds once there’s no more chance of frost, this will make sure you’ll have Zinnia blooms all season long.
• It’s much cheaper than buying plants at the garden center. Many sought-after annual varieties like Amaranth and Alyssum can be costly if bought as plugs at the garden center. It’s so easy to grow your own starts and fill in your garden and containers at a fraction of the cost!

Direct Sowing Seeds vs. Starting Seeds Indoors

There are some seeds that are recommended to start indoors, including smaller seeds and those that need a little extra heat to germinate. Smaller seeds often need to be 'thinned' after they sprout, which is a much easier task indoors at the table then it is outside on your hands and knees. Larger seeds and those with fragile root systems should be sown directly in the ground. There are a few varieties that can be started indoors for earlier blooms or directly sown, it just depends on your preference:

Direct Sow:

• Nasturtium
• Morning glory
• Bachelor button
• Calendula
• Larkspur
• Annual poppy

Start Indoors:

• Cleome
• Snapdragon
• Amaranth (Love Lies Bleeding)
• Sweet Pea
• Alyssum

Direct Sow Or Start Indoors, depending on your preference:

• Sunflowers
• Zinnia
• Cosmos
• Strawflower
• Marigolds

From left to right, different pots to use for starting seeds: plastic cell packs, peat pots, egg cartons, newspaper pots, soil blocks.

Good seed starting soil, a trowel, and a spray bottle are very helpful when starting seeds.

Suggested Tools To Start Seeds Indoors

• Flat Trays - This is the bottom tray that holds your cell packs, but can also be filled with soil to start seeds. After sprouts appear and grow, you can use a fork, spoon, or popsicle stick to remove and transplant seedlings.
• Cell Packs - These usually come 4/6 cells per pack and roughly 8 packs can fit in a standard flat tray.
• Peat Pots - These are great for varieties with fragile roots, like milkweed, as you can plant the entire biodegradable pot directly into the ground without disturbing the root system.
• Soil Blockers - A small metal tool that makes it easy to create cells simply out of moist soil.
• Newspaper Pots - Use one sheet of newspaper per pot and fold lengthwise twice. Roll around a can and then fold over the top to make the base. Slide the can out, fill the pot with seed starting soil, and you’re ready to go! These pots can also be planted directly in the ground when it’s time to plant.
• Egg Cartons - If you have extra egg cartons laying around, each cell can start one seed! When it’s time to plant, cut the cells apart and plant directly in the ground.
• Seed Starting Mix - This is a special, finely-screened mix to help seeds germinate and grow healthy roots. You can use just this to start seeds, or layer potting soil (which is less expensive) in the bottom half of your cells and fill the rest with seed starting mix. Using potting soil on its own often brings mixed results, as it typically includes larger material, such as bark and wood that can block small roots from making contact with actual soil particles - their source of nurtients.

Tools To Cover Seeds & Help With Germination

• Plastic Dome - Plastic domes can be purchased at your local garden center and help add humidity and trap heat in to help the seedlings germinate. Once you see sprouts emerge, remove the dome so that tender young seedlings don't overheat.
• Saran Wrap - Saran wrap can be used the same as plastic domes and can be laid out directly on top of your trays. Again, once seedlings emerge you should remove the saran wrap.
• Heat Mat - Heat mats can be found online and help speed up germination. Place your trays on top of the heat mat until seedlings emerge. If you don’t have (or don’t want to spend the money for) a heat mat, place your trays on top of your refrigerator or radiator to provide similar heat from below. Once seedlings emerge, make sure the trays are moved to a spot with direct sunlight.
• Spray Bottle - Although all of your seedlings should be watered from below (which is why the tray comes in handy), spraying the soil from above with a spray bottle also helps. A spray bottle is gentle enough that it won’t damage the fragile seedlings.
• Grow Lights - If you don’t have a spot in your home with direct sunlight to place your seed trays, a standard grow light purchased at your garden center or online works great.
• Thermometer - This is extremely helpful to determine the temperature in the room where you’re starting your seeds. Most seeds require temperatures no cooler than 65 degrees to germinate.

10 Steps For Planting Seeds Indoors

1. Look at your last frost date (find your Frost Dates here) and check the recommendation for how many weeks before this you should sow your seeds. Varieties like Snapdragons can take upwards of 6-8 weeks to grow before the last frost, whereas varieties like Cosmos and Zinnias should be planted just 3-4 weeks before the last frost date.

2. Seeds with hard shells, such as Milkweed, may need to be cold stratified, scarified or soaked before planting. Learn how to Scarify Seeds here. Learn how to Cold Stratify Seeds here. 

3. Add water to your soil and mix it with your hands. You want the soil to be moist enough that it can be formed into a ball, but not too wet that it isn’t solid. If you don't pre-wet the soil mix, you may notice that water simply runs off the top and doesn't soak in as you'd like.

4. Place your soil in your cells (plastic, peat, newspaper, or egg carton). Pack the soil down with your fingers, add more, and pack it down again. You want to make sure the soil is compact and comes almost to the top of your cell.

5. Spread out your seeds on a small dish to easily pick one up at a time. A small white plate works great as it’s easy to find the seeds!

6. Plant your seeds according to the recommended depth. Most seeds should be placed directly on top of the soil with just a light dusting covering them. We recommend planting two seeds per cell. This ensures you’ll at least have one seed germinate and if both do, you can remove the weaker seedling once they are an inch high.

7. Water from below into the tray. The holes in the bottom of each cell will allow the plant roots to wick up water as needed.

8. Add a plant marker to the tray so you don’t get your varieties mixed up. You can use popsicle sticks or wooden markers you can find at the garden center.

9. Cover with a plastic dome or saran wrap - humidity withh help speed up germination.

10. Find the best spot to place your seeds. A warm, sunny spot indoors is the perfect place to place your trays. If you don’t have direct sun, simply use a grow light. Just be sure that your light is positioned close (within 6 inches) of your seedlings so that they remain short and stout and don't become leggy from trying to reach for the light. This means that you'll need to move your light source frequently, as plants begin to grow. Place on a heat mat if you have one, or place on top of your refrigerator (or in a warm area of your home).