Costmary (Tanacetum balsamita) is one of the medicinal plants that we can grow in the garden, even if it is not one of the best known. Calling it “aromatic” is perhaps improper as it does not release an intense aroma comparable to those of rosemary or lavender, however, it has a pleasant and strong flavor, reminiscent of that of mint and eucalyptus.
For this reason and its ease of cultivation, it is therefore interesting to introduce Tanacetum balsamita in your green space and also in recipes.
In the past, it was also called “Grass of the Bible” because it was used as a bookmark due to the lanceolate shape of its leaves. Today we can also hear it mentioned as spearmint, bitter herb, Madonna’s wort, or good herb.
Let’s see the characteristics of this species and learn how to grow costmary organically in the vegetable garden, in the multi-variegated flowerbed of aromatic species, or even in pots.
Tanacetum Balsamita: the plant
Costmary (Tanacetum balsamita) is a rhizomatous perennial herbaceous plant, native to Asia and the Caucasus and well acclimatized in our continent.
It belongs to the Asteraceae or Composite family like many vegetables we know: lettuce, chicory, artichoke, thistle, sunflower, and Jerusalem artichoke. What interests us about the plant are the leaves, which are very rich in essential oils.
They have an elongated oval shape, with a finely serrated edge. Their flavor, as anticipated, recalls that of mint and eucalyptus but with a more bitter tone.
Where can we grow it
Costmary grass does not have particular needs in terms of climate and soil, it is rather adaptable, even if it suffers from intense frosts in areas characterized by harsh winters and even excessive summer heat.
Compared to other Mediterranean aromatic species, it adapts well to half-shade positions, where the leaves become more tender and fleshy than in the full sun, so it is ideal for slightly shady gardens or balconies where we don’t know well what to cultivate.
Soil tillage and fertilization
The soil that will host this plant must be cleaned of any grass present and tilled in depth. We can carry out the main work with a spade or pitchfork, the latter tool, which allows you not to overturn the soil while moving it well, and therefore more environmentally friendly and less tiring.
After the main tillage, the soil must be hoed to break up the remaining clods and level the surface with a rake with metal teeth.
As a base fertilizer we can add 3-4 kg / m2 of mature manure or compost, but without burying them deeply, but incorporating them into the surface layers of the soil during the work of the hoe and rake.
Transplant of seedlings
It is not easy to obtain costmary grass (Tanacetum balsamita) from seed, so cultivation usually starts by purchasing the seedlings from a nursery.
The transplant is carried out in spring, with a wide temporal window, between March and June. If we decide to transplant more specimens of this species we must transplant them at a distance of about 20-30 cm, otherwise, we will keep at least the same distance from the other aromatic species in the flowerbed. Thereafter, the plants will tend to extend through rhizomes, also occupying additional space. Then we will be able to manage this spontaneous reproduction to create new specimens and transplant them elsewhere at suitable distances.
Costmary grass does not tolerate water stagnation, so it must be irrigated in moderation, as usual, avoiding wetting the foliage but giving water to the base, with a watering can or through the drip irrigation pipes.
As annual fertilization, it is good practice to sprinkle a few handfuls of pelleted organic fertilizer on the ground in spring and distribute diluted macerates of nettle or other herbs with a fertilizing effect.
It is also necessary to keep the space clean of spontaneous herbs, by hoeing and manual weeding near the plants in order not to risk damaging them. Otherwise, we can choose to mulch to prevent the problem upstream, using sheets or natural materials such as straw, leaves, bark, and more.
The plant is quite rustic and damage from some adversity rarely occurs, so it is really simple to implement organic cultivation. Radical rot can occur in the case of water stagnation, so if the soil tends to compact and get soaked with rain, it is better to cultivate on a raised bed.
Growing costmary grass in pots
Costmary grass, as anticipated, is also suitable for cultivation on balconies and terraces, in various types of containers. We choose good soil if possible enriched with real country earth and natural fertilizers such as manure or mature compost.
Collection and use of the leaves
The leaves of costmary grass (Tanacetum balsamita) must be harvested fresh, preferably before the plant blooms. They are very flavoring and have a delicate scent and, as we said, a mentholated flavor.
We can use the leaves for the preparation of infusions, but also omelets, digestive liqueurs, and sorbets filled with ravioli and tortelli. Or we can simply add the raw leaves to the mixed salad.
To dry the plants, they must be placed in cool, fairly ventilated, and not humid places.
Medicinal properties of costmary herb
In herbal medicine, our “bitter herb” is used by attributing various medicinal and beneficial properties to the body, in particular antiseptic.
The herbal tea is used as a supposed natural remedy for flu and stomach pain, its balsamic properties are also exploited for coughs and colds.
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