Nowadays, “clover” refers to the many species of different genera that are similar in their growth habit and the characteristic appearance of the leaves. However, there are differences between the different types of clover when it comes to frost tolerance.
Which types of clover are hardy?
Some types of clover such as red clover (Trifolium pratense) and white clover (Trifolium repens) are hardy and survive periods of frost without damage. Lucky clover (Oxalis tetraphylla), on the other hand, is sensitive to frost and should be kept indoors over the winter. Persian clover is not hardy and is often used as green manure.
Overwintering the lucky clover properly
At the turn of the year, potted specimens of the lucky clover are often given away, whose botanical name Oxalis tetraphylla suggests the four-leaf clovers on these plants. In contrast to other types of clover, lucky clover reacts very sensitively to long periods of frost well below zero. Therefore, this plant can hardly be overwintered outdoors in this country. The specimens grown specifically for the turn of the year usually still have green leaves and can be easily overwintered in a bright location indoors. However, if the lucky clover has been on the terrace or balcony over the summer, it will usually let the leaves wilt and fall into a kind of hibernation. Then its location should meet the following criteria:
- cool but frost-free
- dark
- little irrigation water
- no fertilizer
Hardy clovers
Clover varieties used as livestock feed, such as red clover (Trifolium pratense) and white clover (Trifolium repens), are easily winter-hardy in most locations. Frost damage is rare for these types of clover. However, certain illnesses can cause symptoms that may appear to the layperson to be typical frost damage. The so-called horn trefoil (Lotus corniculatus) is also hardy and can particularly demonstrate its advantages on dry soils. Persian clover, on the other hand, is not hardy, but it is often used as green manure for precisely this reason.
Choose the right time to sow green manure
Some gardeners leave the clover in the bed as green manure over the winter, as the soil is better protected against heavy autumn rain and other weather influences. To ensure that red clover, for example, is sufficiently developed by the onset of winter, it should be sown by September at the latest. Basically, the timing of green manure is also determined by how long the clover will grow in a location and when it should be incorporated into the soil.
Tip
When buying lucky clover, pay attention to the temperature at the sales location: If the clover grown in a pot has already been standing on an outdoor sales stand in frosty temperatures for a long time, it will probably not be an ornament for the recipient for long can serve as a window sill.
