With plenty of light and warmth, you can overwinter basil on the windowsill. Here is what you need to bear in mind when transplanting this kitchen herb. To overwinter basil turns out a little difficult, but not impossible. Since basil is actually native to tropical regions, the culinary herb needs a lot of warmth and does not tolerate frost.
Perennial basil is sensitive to frost and therefore must be overwintered indoors. To do this, lift the culinary herb out of the bed and plant it in a pot with a drainage layer and flower or container plant soil. In winter, basil is best kept in a bright place at temperatures between 15 and 20 °C / 59 and 68 °F. A place on the windowsill or in the winter garden is suitable.
Step by step: winter basil
Cover the drain hole
The pot should have a diameter of about 20 centimeters (8 in). To allow the water to drain freely, place a clay shard curved upwards on the bottom.
Create a drainage
For drainage, fill the pot with a layer of expanded clay about 5 cm (2 in) high. Instead of expanded clay, you can also use gravel (grain size 8 to 16 millimeters). Unlike expanded clay, gravel does not store water, but in winter this property is less important.
Cut a piece of garden fleece to fit the size of the pot.
Lay fleece on expanded clay
The water-permeable fabric separates drainage and soil in the pot. Carefully place the fleece on top of the drainage layer to keep the expanded clay or gravel clean and easy to reuse later.
Fill in substrate
Flower or pot plant soil is suitable as a substrate. Special herb substrates do not provide enough nutrients for basil, which is a heavy feeder. Fill the soil into the pot with a garden trowel.
Carefully hold the basil plant and add enough soil until the top of the bale is just below the edge of the pot.
Press the soil
Use your fingers to press the root ball all around. If necessary, add as much substrate until the roots are completely surrounded by soil and can grow well.
Finally, water the plant well and drain excess water. As long as the temperature is above 10 ° C / 50 °F, the pot can be left outdoors.
Perennial basil is as sensitive to frost as the classic Genovese basil. But the chances are greater to cultivate it in a pot until next spring. Wintering works best with the variety ‘African Blue’. This perennial cultivar forms such decorative flowers that it can also be planted as an ornamental plant in flower beds in summer. It survives the cool season best in light and at temperatures of 15 and 20 ° C / 59 and 68 °F. If you have little space, you can also cut cuttings from the large mother plant and overwinter them planted in small pots.