There are almost 200 species of phacelia, which belong to the family of the rough-leaved plants and are thus related to comfrey, for example. The tansy phacelia (Phacelia tanacetifolia), which is also mainly cultivated here, is the best-known species. It got its name from the similarity of its leaves to the native tansy (Tanacetum vulgare). The annual plant originally comes from Arizona and California. It only found its way to Europe in the 19th century, mainly as a summer-flowering ornamental plant in gardens, but also as a bee pasture and green manure.
The right location
The tansy phacelia is almost indispensable for the natural garden. We can enjoy the filigree blue flowers just as much as the countless insects they attract. Phacelia loves sunny locations and is very undemanding and easy to care for. It is also resistant to diseases and pests. Only frost is not tolerated, which is why the foliage dies at temperatures below -5 °C.
Sowing and growth of Phacelia
You can sow this beautiful flowering plant directly in the open from the beginning of May to the beginning of September. The seeds are dark germinators and are therefore lightly raked in and well watered. After only two weeks of germination, the plant starts to grow furiously, so that you can look forward to the first flowers after six to seven weeks. Phacelia has a strong tendency to self-seed, which is why you can expect more plantlets the following year. Phacelia is also a good mixed crop as it protects other plants from nematodes and cabbage hernia.
Soil improvement with Phacelia
In agriculture, the tansy phacelia is used as a green manure plant, because it forms a lot of plant mass in a short time. It survives dry periods without any problems and is also considered an optimal catch crop, as it does not transmit diseases. Soil fertility is promoted and the dense foliage provides good soil shade and weed suppression. Phacelia green manure leaves behind a well-rooted, gare topsoil. The green manure is sown between September and October and cut after the first frost. The cuttings remain on the beds until spring, when they are worked under.
Phacelia honey – exotic and rare
The colourful, pleasantly fragrant flowers attract countless bees with their nectar and pollen. For this reason, its special importance as a bee pasture was recognised in the 1980s, which is also where the name “bee friend” comes from. Some beekeepers have sown large areas of phacelia as a high-yielding bee crop. Yields of 500 kg of honey per hectare and flowering season are possible. Collecting nectar is difficult, however, because the sugary nectar is found very deep in the flower. The busy bees have to crawl deep into the nectar cup.
But the effort is worth it: During the flowering period, which lasts up to four weeks, the bees produce a unique honey that convinces with its mild taste and typical aroma. The honey has a creamy consistency and an intense sweetness. Its smell is exotic and its aroma floral. The colour is similar to that of rape honey and varies from whitish to light beige. However, Phacelia honey is still a rarity in Europe.
Beekeepers also rave about the healing effect of Phacelia honey. It is said to have an antibacterial effect and is recommended for sweetening cold teas. Applied externally to the skin, it is said to have an anti-inflammatory effect.
Phacelia – a real insect friend
Not only busy honeybees are attracted by the scent of phacelia – butterflies, wild bees and bumblebees also feast on the multitude of purple flowers. This is why the pretty plant is very often included in flower mixtures for bees and other insects.
Caution for sensitive skin
Apart from its use as honey, there are no records of the tansy phacelia being used in medicine or as an edible wild plant. Although the plant is not poisonous, it contains skin-irritating substances – the so-called phacelioids – which can trigger contact allergies in sensitive people. In this case, you should protect your skin and wear gloves when handling the plant. The tansy phacelia is also harmless to animals – on the contrary, it is even popular as a food plant.