Summertime is strawberry time. And because you often can’t have enough of the sweet little fruits in your garden, it’s worth growing offshoots. Here is how you can easily propagate strawberries yourself.
Strawberries can be self-propagated in different ways. In addition to rapid multiplication by offshoots, you can also sow the small nuts.
The tiny, yellow-green seeds on the outside of the strawberry (Fragaria) are actually called nuts. Therefore, botanically speaking, the strawberry is not a berry, but a gleaning nut. Especially in the case of monthly strawberries (Fragaria vesca var. semperflorens), which rarely form offshoots, these nuts are still used today to propagate strawberries. However, other strawberry plants can also theoretically be propagated via their nuts. However, propagation via offshoots is by far easier and has another significant advantage: the stolons, as the offshoots are called, are quasi clones of the mother plant and thus guarantee varietal authenticity.
If you have well-rooted strawberries in your garden, you can easily propagate them by cuttings. This way you get many young plants at no extra cost to increase the strawberry harvest, to give away as a gift or as an educational experiment for children. The daughter plants are placed in small clay pots after the harvest period, so you can easily remove and transplant them in late summer.
Propagate strawberries: Growing offshoots
The best time to propagate strawberries via offshoots is between late July and early August. When the strawberries form offshoots that are already rooted, they can be separated from the vine to the mother plant. They should be carefully dug out and replanted directly. Layer that have not yet formed roots, or hardly, are best planted in small pots. In doing so, they still remain connected to the mother plant until the containers are fully rooted. Alternatively, the layer can be mounded and pressed to the ground with a wire to establish soil contact. Since strawberries have an increased need for potassium, they should be planted in a nutrient-rich soil such as our Plantura Organic Tomato & Vegetable Soil. This is already pre-fertilized and thus ensures the nutrient supply of the strawberry plants.
Most strawberry plants will form more than one offshoot. The offspring growing closest to the mother plant are usually the strongest and largest. They have a higher probability of flowering the very next year.
Common mistake: Often plants that bear few fruits form the most offshoots. After all, they have energy left over to produce them. If you don’t mark the good-bearing specimens, you tend to propagate just the poor-bearing ones with their many offspring. Therefore, marking good-tasting, healthy, high-yielding plants with sticks or tags at strawberry harvest time has proven beneficial – especially for early-maturing strawberry varieties.
If one wishes to obtain a particularly large number of offshoots from a strawberry plant, all flower shoots of that plant can be broken off. In this way, the plant does not have to divide its energy between fruit and offshoot formation and can form more offspring. However, this procedure is only useful if a very good harvest has already been observed and marked on the corresponding plant the year before. Since the yield decreases sharply from the third year in the same bed, this procedure is recommended in the third or fourth year to plant another bed with the best offshoots of strawberries.
By mid-August at the latest, all the offshoots should be in the new bed so that strawberry plants can develop from them. Later, the plants will grow poorly.
At a glance: Propagating strawberries via offshoots
- Mark strawberry plants with good crops and tasty fruit using sticks or labels at harvest time.
- Select only offshoots from healthy plants.
- Replant offshoots that are already rooted directly.
- Plant unrooted offshoots in a small pot and leave them with the mother plant for a while; separate them from the mother plant no later than mid-August and plant them in the bed or overwinter them in a pot in the cellar.
- In order for the strawberries to get through their first winter well, it is helpful to give them additional protection.
Sowing strawberry seeds
With generative propagation, i.e. propagation via seeds, cross-breeding often occurs and it cannot be ensured that the same characteristics occur as with the mother plant. Therefore, a true-to-type propagation should better be carried out by cuttings.
As already mentioned, the seeds of the strawberry are botanically speaking nut-like fruits, so-called achenes. They are located on the fruit skin of the strawberries and can be used for generative propagation. To obtain the seeds, the fruit skin is thinly peeled off and dried. If the entire fruit is pulped instead, there is a risk that it will begin to rot.
Once the strawberry seeds are dried, they can be sown in June or July. It is advisable to place a few seeds in a pot. This is ideally filled with a 1:1 mixture of sand and a high-quality, low-nutrient seeding soil. The loose structure and low nutrient availability will ensure optimal root growth. The strawberry seeds are only thinly covered with the soil mixture, as they are light germinators.
The optimal germination temperature is between 15 and 18 °C / 59 and 64°F in a warm-humid climate. This can be achieved with the help of a plastic cover or cling film. Especially in midsummer, germination is more likely to succeed if the pot is not in full sun and is thus better protected from drying out. Germination takes about 2 to 4 weeks. When the seedlings have formed about 3 leaves, they can be separated and planted out in more nutrient-rich soil. Seeds should not be sown later than the end of July, as the young plants need a certain size to survive the winter well.
Overwintering is possible outside, you can additionally protect the young plants here with a fleece or some brushwood or straw. Sowing in the spring can succeed, with monthly strawberries produce fruit even from July. With other species, the first harvest then occurs in the following year.
In a nutshell: propagate strawberries by seed
- Strawberries that do not form offshoots, such as some monthly strawberries, can only be propagated by sowing seeds.
- The fruit skin of the ripe strawberries is separated and dried.
- For sowing, use a low-nutrient sowing soil.
- The seeds are only lightly covered with substrate, as they are light germinators.
- Germination occurs at temperatures of 15 and 18 °C / 59 and 64°F after about 2 – 6 weeks.
- Strawberry seeds can still be resown until mid-July, otherwise not until next spring.
The best time to fertilize strawberries is after harvest, so in July for aromatic and robust garden varieties. At this time, the plants form the flowering plants for the coming year. Recommendation: Spread 15 grams per square meter of horn meal and lightly work it into the soil.