How to Sow Strawberry Seeds (Indoor Method)

While it’s easiest to grow strawberry plants from runners or transplants, you can also grow new plants from seed using these tips. This tutorial provides tips for success no matter which strawberry variety you choose to grow.

Once you’ve sprouted your strawberry seeds, this has my best tips for growing strawberry plants.

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Growing Strawberry Plants From Seeds

After years of growing strawberries from store-bought plants and by propagating runners from existing plants, I decided to try growing new plants from seed.

If you simply want garden-fresh strawberries this season, start with established plants.

Growing strawberries from seed is much slower and you won’t get fruit this year. But—it’s quite rewarding if you enjoy a little challenge or are simply curious—or both!

I have experimented with a variety of growing methods.

My tests included following recommendations from other growers and some unusual (and often very misleading or made-up) tips from TikTok and Instagram.

Spoiler alert: planting a whole or sliced strawberry directly in soil is not going to grow strawberry plants! Or, if it can, it’s going to take longer than the two years I waited.

These are my top tips for growing from seed:

1) Use fresh seeds

While strawberry seeds can remain viable for 5 years, I had the best germination rates with seeds under 2 years old.

For what it’s worth, I have only had success with commercial seeds, not seeds saved from fruit.

If you try this, buy fresh seeds.

2) Cold stratify the seeds in fridge for 30 days prior to sowing

Not all types of strawberries require this but many do. So, if you unsure, go ahead and give the seeds time in cold conditions (in your fridge) prior to sowing. It won’t hurt and it probably helps.

3) Sow seeds on surface of potting mix—they need light to germinate

This may be the top reason why attempts fail—if the seeds are buried, they won’t sprout.

With these tips in mind, let’s walk through the process.

How to Sow Strawberry Seeds

When to Sow Strawberry Seeds

It’s ideal to begin this process in late winter. This should allow enough time to sow and grow during spring and summer and have established plants in the ground by fall.

Keep notes in your phone or garden journal including dates, observations, and actions taken for future reference. At minimum, snap some photos as you go.

In this example we’ll start the process in March in a climate like mine here in Ontario where the main outdoor growing season runs from May to October.

Prepare Strawberry Seeds for Sowing

March

The first step is to chill your seeds in the fridge for at least 30 days.

The fridge temperature should be 34 to 39°F (1 to 4°C).

Exposure to a period of cold, winter-like conditions prior to sowing is called “stratification” or “vernalization” depending on the circumstances.

Here we’ll call it stratification. There is a detailed guide on seed stratification here.

Stratification can be “wet” or “dry.”

• To dry stratify, place the seed packet in a sealed food storage bag at a consistently cool spot in your fridge for 30 days (or more).

• To wet or moist stratify, sprinkle the seeds on a plate of moist paper towel or sand or potting mix and place everything in a sealed food storage bag in the fridge for 30 days (or more). Check every few days and re-moisten as needed.

Notes

I’ve had the most consistent results with dry stratification. I think this is because it was easier to sow the dry seeds on the surface of the potting mix.

Rapid Method

The rapid method takes a week instead of 30 days. I’ve seen other gardeners say it works but it’s not been consistent for me.

With this method, the seeds are placed in ziptop plastic food bags with a small amount of moist sand or potting mix. Place in fridge for 24 hours and then move to freezer. After another 24 hours, move back to fridge and so on for at least 7 days.

You can read more about it here: see Fridge Freezer Method in Germination Trick for Delphinium Seeds (Cold Stratification in Fridge).

Sowing Stratified Strawberry Seeds

April

After 30 days in the fridge, your seeds are ready for sowing.

You can sow them any containers with drainage holes—whatever you have room for.

For example:

• Flowerpots (2 to 3-inches tall and wide, or larger)
• Plant trays (at least 2 inches deep)

The larger the pot, the less likely you’ll need to transplant later but they do take up a lot of space indoors.

• Fill flowerpots or trays with moist potting mix.

• Place seeds on surface of potting mix.
  
  It’s the combination of contact with the moist potting mix and exposure to light that will make them sprout.
  
  You can either space the seeds apart now (an inch or so apart) or sprinkle them and thin them out later.
• Place under grow lights or near a sunny windowsill.
  
  Avoid harsh sun and do not allow the potting mix to dry out.
  
  I use simple grow lights on timers for approximately 12 hours per day. You can see my grow light setup here.
  
  The ideal soil/potting mix temperature for strawberry seed germination is 18-24°C (65-75°F).
  
  (Optional) If relative humidity is low (below 40%) in your home, place a piece of clear cling wrap (food wrap) loosely over everything to help keep moisture in. Remove it if you get water build up on the plastic or when seeds start germinating.
• Set a reminder on your phone to check your seeds every few days.
  
  Moisten (water) potting mix as needed with a mister or water from below into a tray. Pouring water directly into the potting mix can make these tiny seeds wash away.
  
  I like using a moisture meter to check the potting mix but you can also use your fingertip.

What to Expect

May to July

It can take weeks or months for strawberry seeds to germinate. And you might not notice at first—they are tiny!

I’ve seen sprouting as quickly as 10 days after sowing and waited as long as 5 months—all from the same batch of seeds.

Plus, they can really vary in size at first—some tiny, some larger—all with the same number of leaves. I keep all of them because eventually the little ones seem to catch up.

Seedling Care

Ongoing, the plants need adequate water and light.

It’s best to have at least 12 hours of light a day if you can. I use grow lights on a timer so I don’t have to worry about hours of sunlight.

LED Grow Lights

Recommended LED Lights

Seedlings | Barrina Super Bright White LED Lights | Amazon

These lights work nicely for indoor seed starting and growing young plants until it’s time for outdoor transplanting.

Indoor Flowering & Fruiting | Barrina Full-Spectrum LED Lights | Amazon

If you need lights for long-term growing including plants that can flower and fruit indoors, choose full-spectrum bulbs.

Potting Up

The term “potting up” simply means moving the plant to a larger pot.

Once your seedlings have a strong stem and several leaves (3 or more), you can transplant them to individual pots as desired.

These plants grow a lot of delicate roots both vertically and horizontally in the soil and tend to get all tangled up. For this reason, I like each plant to have its own container.

Transplanting Outdoors

June to August

Before transplanting your strawberry seedlings outdoors, make sure the timing is right for planting strawberry plants and you “harden off” your seedlings first.

“Hardening off” means gradually getting the plants accustomed to outdoor conditions over a period a time. You can read how to harden off plants here.

Some strawberries are hardier than others but typically you want to wait until the risk of frost has passed and the soil is consistently around 60°F (15°C).

You can continue growing your strawberry plants in pots or transplant them into the ground.

Because the young plants are quite delicate, I prefer growing them in containers where I can protect them from harsh weather and—later when fruit forms—from animals.

Fertilizer

• Pots – If your potting mix does not have added fertilizer, you can add some now following the product instructions for potted, fruiting plants.

• In-Ground– If your soil requires it, add organic fertilizer. I use homemade compost. Space plants 1 to 2 feet apart if you have room. This makes it easier to propagate the runners (new shoots that bring the next generation of plants) later on.

Flowering and Fruiting

Your new plants will probably not produce fruit in their first year.

• Protect them with a thick (4-inch) layer of leaves or straw in the winter and uncover them as temperatures warm in spring.

Resources

Strawberry Growing Guide

• How to Grow Strawberries: Basic Tips That Really Work has everything you need to continue growing your strawberry plants for years to come.

~Melissa the Empress of Dirt ♛