Table of Contents
- Moderately hardy
- Recognize frost damage
- Cutting helps
- Prevent frost damage
- frequently asked Questions
rosemary is not completely hardy in our latitudes. In very harsh winters, the popular culinary herb can quickly become damaged by frost. If the rosemary is frozen, it can still be saved with the right measures.
In a nutshell
- Do the acid test
- cut frozen shoots
- Cut back after flowering
- do not cut into old wood
Moderately hardy
The evergreen Mediterranean subshrub shouldn't be used in any Herb bed miss. Rosemary (Salvia rosmarinus) is not only a popular herb in the kitchen, it is also valued as a medicinal plant. It originally comes from the Mediterranean region. This already shows that the subshrub can only tolerate cold temperatures poorly. In this country, the culinary herb is very sensitive to frost. However, with proper winter protection, rosemary can normally withstand cold spells of up to -10 degrees undamaged. After even lower temperatures, the rosemary shoots can sometimes be frozen to death in spring. The plants only reach winter hardiness in the third year of standing. This is from
location and soil dependent.
Notice: Various particularly hardy varieties such as "Arp", "Veitshöchheim", "Backnang", "Bavaria" or "Heilsberg" have been created through breeding. In a favorable location, these varieties can withstand temperatures of at least -20 degrees.
Recognize frost damage
The full extent of the frost damage will only really be visible in April. More or less brown needle leaves are then visible. If there are only a few brown colored needles, don't worry. That is normal. Usually nothing needs to be done here. The new shoot will overgrow this needle. If necessary, however, they can easily be stripped off by hand. It becomes more problematic, however, when several shoots are colored brown. This could be a sign that the rosemary has frozen to death. If the whole plant is affected, it can usually hardly be saved.
Do the acid test
With the help of a so-called acid test, it is very easy to determine whether the rosemary has really frozen to death. The implementation is very simple and also possible without aids:
- Lightly scrape off the bark of the shoot with a fingernail
- alternatively use secateurs or knives
If a light green color appears, then there is still life in the drive. Further measures can now be taken to save the plant. However, if a brown color of the shoot is visible under the bark, then it is frozen. If the whole plant is affected, you can dispose of it.
Cutting helps
Cutting back the frozen shoots stimulates new shoots in the evergreen subshrub. However, it should not be done immediately in April, as the rosemary is already here blossoms has started. You should therefore wait until after flowering before cutting. Normally the flowering period is over at the end of May. By the way, late frosts no longer have to be expected. Other reasons for cutting at the end of May are
- Plant thrives properly
- young, green shoots easily recognizable
- Interfaces close faster
- Fungal diseases have no portal of entry
- then grows nice and bushy
Carefully apply the scissors
For the pruning, a clean and sharp secateurs be used. It should not then simply be cut loose. There are a few things to consider in order not to damage the plant even more:
- do not cut into old wood
- otherwise will not sprout again
- only remove brown and thin tips
- Shorten the shoot to the first green needle leaves
- Leave 1 cm of the wood grown last year on the shoot
Prevent frost damage
Even when planting rosemary, the plant can be prevented from freezing in very cold winters. There are also other measures to bring the subshrub through the cold season, such as
- Plant hardy varieties
- choose a warm, sunny location protected from cold north-easterly winds
- Pay attention to permeable soil (waterlogging in winter often causes frostbite)
- always plant in spring (there is enough time to root)
- regular pruning after flowering (new shoots offer better winter protection)
- last harvest in October (better ripening of the wood)
- Winter protection is important
- Spread a layer of foliage around the plants
- cover everything with spruce twigs
- remove in spring
- Hibernate potted plants in the house in a light and frost-free environment
Night frosts can normally occur up to the ice saints in mid-May. Until then, the plants need protection. They should be covered with a fleece at night during this time.
Notice: In an optimal location, the sun does not come out until midday in winter. This allows the plant to warm up slowly and the plant cells do not burst due to large temperature differences.
frequently asked Questions
If possible, no more shoots should be harvested from outdoor plants. The situation is different with potted plants in the house. Some shoots can be cut here if necessary.
The soil should be well-drained, loose and poor, if possible sandy. The subshrub loves a neutral to alkaline pH. He is lime tolerant. Heavy, loamy soils are not suitable for cultivation.
Normally the plant is quite undemanding. A small amount of compost or horn shavings in the spring is sufficient for garden planting. These only have to be poured on very hot days. Container plants, on the other hand, need fertilizer every six weeks, in the form of liquid fertilizer. It is poured here when the top layer of soil has dried.
