Winter Sowing Flowers – A Guide for Beginners

Have you tried winter sowing? Winter sowing flowers is a great way to warm up your green thumb during the winter months. It can give you a head start on the growing season, plus it’s a budget-friendly way to grow as many flowers as you want! Check out my Winter Sowing Flowers – A Guide for Beginners!

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What Is Winter Sowing?

If you tend to think of flowers as fragile, you’re not alone. Many gardeners do! However, the winter sowing method is a great example of how we often baby our plants more than necessary. In many cases, allowing nature to work is actually the best method! 

Starting seeds outdoors is not only an easy way to get a head start on growing your favorite flowers, but it can also create hardier plants. Winter sowing mimics the period of cold stratification. This breaks down the seed’s outer shell and allows it to germinate at the right time. And because the seeds are exposed to the elements throughout the winter months, there’s no need for hardening off in the springtime. This method is best for growing zones 3-9. (You can find your zone HERE via the Farmer’s Almanac.)

Why Winter Sow Flowers?

As a busy mom and business owner, I love using simple methods to grow as many beautiful flowers as I can! Winter sowing totally fits the bill and my Lazy Garden Girl personality. Here are some reasons why you might love winter sowing, too! 

• Inexpensive. For this method, you don’t need any fancy tools. Forget grow lights, heat mats, and even seedling trays. Some plastic containers, water jugs, or plastic bags are just about all you need to form mini greenhouses that will grow strong seedlings starting in the middle of the winter! (see all my supplies here)
• Early blooms. In many cases, when you winter-sow seeds, you’ll find that you have blooms in the early spring months. And who doesn’t want more flowers as soon as possible?!
• Better-acclimated plants. Winter-sown seeds tend to be better acclimated, producing hardier plants than the flowers you’ll sow in the springtime. 
• Low maintenance. Winter sowing is somewhat of a “set it and forget it” method. Plus, it takes some planting off your plate that you would otherwise be doing during the busy spring months.
• More space in your home. Starting seeds indoors can take up a lot of space, especially if you want to start many different trays. Winter sowing keeps everything outside. No more clearing off every indoor surface for seedlings!
• A chance to garden in the winter! Although it doesn’t take a lot of time, winter sowing flowers provides a reason to get your hands in the dirt during the winter season. If you’re like me, you might start getting a little antsy in the winter weather. Sowing some flowers is a great way to keep gardening during the coldest time of year!

Supplies You’ll Need

• Clean, plastic milk jugs, clear plastic containers, or plastic bags. We’ll go over each method below so you can choose the one that fits your style best!
• Potting soil or seed-starting mix. Don’t worry too much about the brand you choose. For best results, just make sure that your soil drains well and isn’t too heavy.
• Seeds. Below, we’ll dive into which flower seeds are best for winter sowing. Johnny’s, Park Seed, and Earth Science are a few of my go-to places for seed orders.
• A waterproof marker or paint pen, for labeling your containers.
• A sharp knife or scissors, for cutting drainage and ventilation holes and for cutting your milk jugs in half.
• Duct tape, for sealing your jug after planting. 
• Clothes pins and sticks, for the plastic bag method. 

Winter Sowing – 3 Methods for Starting Your Flowers in the Winter

1. Milk Jugs

The first – and perhaps most popular – way to winter sow is by using milk jugs to create a miniature greenhouse. Although milk jugs work especially well, you could also use vinegar jugs, 2 liter soda bottles, or juice containers. 

1. Start by using your knife or scissors to poke 5-6 drainage holes in the bottom of the jug. Then, cut a few slits in the shoulders of the milk jug (near the top) for ventilation holes.
2. Next, you’re going to create a hinged lid by cutting around the center of the jug on three sides. Cut about halfway down. 
3. After that, add about 3-4 inches of potting mix to your milk jug, pressing it down gently. Water the soil enough to make it moist, but not soaked.
4. Now it’s time for planting! Check your seed packet for instructions on planting depth. 
5. After planting, use a waterproof marker or paint pen to label your container. You may also want to consider adding a plant tag inside the jug just in case your marker gets faded. 
6. Next, close the jug and use duct tape to seal around each side. 
7. Place your jug in a location that’s sheltered from strong winds and gets partial sun. Finding a spot next to a house or porch can work well. Make sure it’s exposed to the elements – your plants will need to be able to get some moisture from rain or snow through the ventilation slits. 

2. Plastic Containers

Another way to winter sow is by using plastic containers, such as salad containers, large, clear plastic tupperware, or take-out containers. You’ll want containers that have clear lids and aren’t too shallow.

Since most plastic containers are not as deep as milk jugs, you may need to remove your seedlings sooner in the springtime, or choose plants that don’t grow as tall.

Winter sowing in plastic containers is similar to the milk jug method.

1. Start by poking some drainage holes in the bottom of the container. Then, add some slits in the lid.
2. Remove the lid and add a few inches of potting mix, pressing it down and watering gently.
3. Follow the instructions on your seed packet for planting your seeds in the soil.
4. Use a waterproof marker to label the outside of your container, and consider adding a plant tag inside, too.
5. Add the lid back to your container.
6. Keep your winter sown flowers out of strong wind, but somewhere where they can be exposed to the elements to receive some rain and snow through the ventilation slits.

3. Plastic Bags

The plastic bag method is another super simple option that works well in zones 3-9. For this method, you’ll need gallon-sized plastic bags (like Ziplock bags), potting soil, seeds, a marker, scissors, clothes pins, and some sticks (heavy-duty marshmallow roasting sticks work well!). This is the method I decided to do!

1. First, cut three small triangles in the bottom of your plastic bag while it’s still folded. These will serve as the drainage holes. 
2. Next, label your bag with the name of the flowers you’ll be planting in each one. 
3. Add enough potting soil to fill the bag about 1/4 of the way full. Wet your soil, then squish the bag flat to allow the excess water to run out.
4. Sprinkle your seeds into the bag. Then, add a bit more soil on top and flatten the bag again.
5. Zip the bag closed most of the way, leaving a 1-2″ opening. Pinch a clothes pin in the opening to keep the bag slightly open to receive snow and rain.
6. Insert a stick through each side of the bag near the top. You can add a handful of bags on each set of sticks. Then, lay the sticks across two raised beds, a couple stacks of pavers, or some logs. Anything will work, as long as it keeps your bags upright and resting slightly on the ground.

How to Transplant Your Winter Sown Flowers in the Springtime

Once your seeds begin sprouting in the spring, you’ll need to start giving them some more ventilation so they don’t overheat. When it begins warming up, add some more ventilation and water holes to your containers. On warm days, open the lids, being sure to close them again before nightfall. 

After all danger of frost has passed, you can remove the tops from your containers. Then, when they’re ready, simply remove your plant starts from the containers and transplant them just as you would if you sowed them indoors. 

Best Flowers for Winter Sowing

What are the best flowers for winter sowing? Perennials and hardy annuals tend to be good candidates for this method of planting. Here are some of my favorites! 

1. Black Eyed Susan

These native plants are easily recognized by their bright yellow petals and telltale black centers. They thrive in full sun and well-draining soil.

2. Calendula 

Calendula is beloved for its bright, cheery flowers, but it also has many other uses. Calendula has all sorts of medicinal benefits and is an excellent addition to many homemade cosmetic products. It’s an annual herb and loves full sun or partial shade. 

3. Cornflower

These disc-shaped flowers are hardy and grow to be 2-3 feet tall. They’re perfect for borders and thrive in full sun.

4. Cosmos

Cosmos are an easy choice for direct sowing. These hardy flowers can grow 1-6 feet tall. As they grow, they may need some support to help keep them standing steadily. I purchased the Double Clicks from Johnny’s Seeds.

5. Echinacea

These classic coneflowers thrive in full sun to partial shade. They take a while to mature, so they’re ideal for starting early with winter sowing.

6. Foxglove

Foxglove is excellent for attracting pollinators. It produces colorful, bell-shaped flowers that are especially fitting for cottage gardens. Foxgloves usually take two years to bloom, but your patience will be well rewarded!

7. Lupine

Lupine blooms early in the year and is a great option for winter sowing. These spiked flowers can be shades of blue, yellow, purple, white, and red.

8. Morning Glory

Morning glories show their faces in the morning hours and hide away in the afternoon and evening. They bloom for months, giving you a beautiful morning wake up for much of the growing season.

9. Petunias

Petunias are a great choice for hanging baskets and retaining walls. They’re hardy flowers that thrive in full sun. 

Petunias need some light to germinate. When planting them in milk jugs, sprinkle some soil lightly over top of them without covering them too deeply. 

10. Poppies

Poppies can be annuals or perennials. They love full sun and make a classic addition to any flower garden.

11. Queen Anne’s Lace

These delicate flowers are amazingly hardy and can blossom even in dry soils. They’re wonderful for attracting pollinators to your garden, but they can spread quickly! 

12. Snapdragons

Snapdragons make wonderful cut flowers and can last for 7-10 days in a vase. These spiked flowers come in a variety of colors and do well in cold temperatures. They’re perfect for winter sowing. 

13. Sunflowers

Sunflowers are another good option for winter sowing. They do best in a sunny location with nutrient-rich soil. Sunflowers sometimes need staking as they grow taller.

14. Sweet Peas

These sweet-smelling flowers love to climb up trellises and are a classic choice for cottage gardens. They love full sun and typically bloom for 6-8 weeks. I got my sweet peas from Emilie of Flower People!

15. Zinnias

Zinnias are my top choice for easy, hardy flowers that look gorgeous in cut flower arrangements. They bloom quickly and come in a rainbow of colors. I will winter sow these later than the others, probably closer to March as they will need to be babied a bit more.

Check out all of my free zinnia resources in The Lazy Girl’s Garden Club! 

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xoxo,

Kelly