About Strawberry Seeds
Each strawberry has about 200 seeds. Although we call them seeds, those tiny flecks are really the actual fruit – the sweet flesh is just a sort of accessory. Seeds like this are known as achenes. For that matter, the strawberry isn’t a true berry, either, it’s an aggregate fruit. It is also unique in that it is the only fruit in the world with “seeds” on its exterior.
Germination is often the toughest part of growing strawberries from seed. Here’s why:
- Seeds need cold stratification in the freezer for three to four weeks.
- You must start indoors and keep them under grow lights at a constant temperature of 65 to 75°F (18-24°C).
- Germination may take as long as six weeks.
The most widely available strawberry seeds are usually Alpine types. These are very close to the original wild forms, which readily spread by both seed and runner. You’ll have to look hard to find regular commercial strawberry seeds, although you may find a few old-fashioned heirloom varieties. Many strawberry seeds are from hybrid varieties; you can’t save seed and get the same plant in the future.
Open-pollinated seeds are the best choice; make sure they are only pollinated by plants of the same variety – hand-pollinate if necessary. Pick strawberries. Blend in one cup of water for about five seconds. Let sit until viable seeds sink; pour off the debris on top and allow seeds to dry. You can also press the strawberry pulp through a sieve, rinse the seeds and let them dry.
Starting the Seeds
Start your seeds indoors between December and February. Cold stratify them as noted above and let them come to room temperature while still sealed. Use pre-moistened, sterilized seed mix in trays or small containers. You only need an inch or two of container depth and should just barely cover the seeds. Place under grow lights and keep soil moist but not soggy.
Your seedlings will be very small at first. They are ready for planting out when they have grown a third true leaf. It’s best to move to individual pots or flats first and harden the seedlings off before planting outside. About three weeks after the last frost, transplant to the permanent bed or container. Grow strawberries in well-drained sandy loam with plenty of organic matter.