Growing strawberries from seed is a challenge, a real challenge. If you've never grown strawberries before it is advisable to start with already established plants purchased from a reputable seller. Most varieties will send out runners from which you can propagate new plants to get your strawberry patch established and productive for years to come.
If you are up to a challenge and want to try and produce some strawberry plants form seed here goes ....
Remove Seeds From Strawberries
Strawberry seeds as I am sure you are aware are very tiny and to boot they are embedded in the flesh of the fruit. They can however be painstakingly removed from the berry and used to produce new plants.
I have flicked them out with a toothpick, which requires some manual dexterity and patience, but there are better methods, especially if you're going through a lot of berries.
Cut the stems and green leaves and vegetation off.
Hollow out the berry, removing only the fleshy interior that contains no seeds. Remaining will be the outer layer with the seeds still embedded.
Place the outer layers in a blender and cover them with water, just a little bit, enough to cover the berries is all you need.
Blend the strawberry mash with the seeds on a low setting for a few seconds. The seeds are minute and will not be destroyed by the blender blades. The seeds that float to the top are no good. The seeds that sink to the bottom are the good ones that you'll have the highest success rate with.
Skim off the strawberry pulp and bad seeds, a small hand held strainer works just dandy. The pulp you skimmed off is good to make a smoothy out of, or will also work well in the compost heap. The seeds you're saving, from the bottom can be poured into a fine mesh strainer or cheese cloth, or you can remove them from the blender by hand.
Strawberry seeds require cold stratification to be viable. Place your seeds in an air tight container and leave it in the refrigerator [Not Freezer] for roughly one month.
Placing some sterile soil or clean moist sand in with the seeds is helpful. The seeds need both water and oxygen during their cold stratification. The sand will retain moisture while allowing air to pass through it. Cold stratifying seeds can be done without the sand, bu not as successfully. The sand increases the survival rate for seeds after their dormancy. Mix the sand and seeds before refrigerating. Not too much sand though, strawberry seeds are very tiny and will easily get lost in the sauce. You'll also be planting the seed and sand together once they break dormancy.
Once you remove the air tight container from the refrigerator allow it to reach room temperature before opening. Opening it prematurely will reduce the amount of viable seeds as water condensation from defrosting diminishes the quality. You want to imitate nature in this case - strawberry seeds that germinate naturally in an outdoor setting do not go from freezing temperatures to spring in an hour or so , it is done gradually. Strawberry seeds need temperatures between 40 and 60oF to break out of their dormancy and begin development.
As temperatures increase and the strawberry seed emerges from its dormancy it requires water, no fertilizer just water. The seed coat in this phase will swell and soften. If the seed does not receive adequate moisture during this phase - poof - it dies.
Sow the seeds in trays or pots using moist sterile starter mix. Broadcast the seeds across the soils surface and sprinkle a very fine layer of soil across the top.
Self Watering Containers are best for this endeavor as the process of watering strawberry seeds, which are minute and fragile will wash them further into the soil and diminish your odds of success.
Another method used to water strawberry seeds is a wicking medium. The idea is to wick up water from below so that the soil remains constantly moist until germination occurs. Wicking mediums can be felt or cloth that are kept wet and placed beneath the trays, as the soil dries it draws up moisture from the cloth.
Temperatures of 65-75oF are best for germination. Ventilation once the plants germinate is essential as is light. A well lit location or artificial light should be provided. Germination takes anywhere from 7 - 30 days. Unconditioned seeds take up to 30 days while conditioned seeds can germinate in as little as 7- 14 days depending on the variety.
Once your young plants have several true leaves, they should be transplanted, either into individual pots, or into the ground if the weather / climate is suitable. Hardening off your seedlings is advisable if planting outdoors.
Direct Seeding Strawberries
Direct seeding strawberries into an outdoor garden bed, without exception, reduces the success ratio. Plant more seeds than you anticipate getting mature plants from.
Select a site with full sun. The soil should have a pH range of 5.5 to 6.5. As soon as the ground is workable and the soil warms in early spring, GENTLY press the seeds into moistened soil. Do not cover them over, even though some may blow away so long as they are kept moist the majority will not.
Keep the bed moist during the germination period. If using over head watering - such as a hose, try to keep the water flow as a mist, a torrent of water will scatter and displace seeds.
Hybrid Strawberries such as Surecrop, Delite, Guardian, Kent, Lateglow, Lester, Midway, Redchief, Tribute, Tristar, and Earliglow when grown from seed need the same treatmment as other strawberry seeds which includes cold stratification. However, hybrid varieties will not grow true from seed, they revert to one of the parent varieties. It is recommended to buy plants or crowns instead of trying to grow these strawberries from seed to ensure you get the right cultivar.