The essential oils of dittany not only give the perennial a wonderful lemon aroma, they can also ignite in high heat. Here you will find everything you need to know about planting and caring for this unusual flowering plant. Attention! The plant is protected!
Profile of dittany:
Scientific name: Dictamnus albus
Plant family: rue family (Rutaceae)
Other names: burning bush, gas plant, fraxinella
Sowing time: autumn
Planting time: spring or autumn
Flowering period: June to July
Soil quality: loamy, calcipholous, moderately nutrient rich
These information are for temperate climate!
Use as a medicinal herb: not used anymore due to its toxicity.
Use in: flower beds, embankments, under wood planting, flower garden, prairie garden, forest garden
Winter hardiness: hardy, USDA Plant Hardiness Zones: 6
Bee and insect friendly: Yes
Plant characteristics and classification of dittany
Plant order, origin and occurrence of dittany
The dittany or burning bush (Dictamnus albus) is the only species of the genus Dictamnus. Botanically, the fragrant perennial belongs to the rue family (Rutaceae). The natural sites of the dittany range from Southern Europe to China and Korea. In Central Europe, the Burning Bush can be found growing wild, mostly in groups in limestone grasslands or in the pine forests located on it. But it can also be found on sunny hills or in the light bushes. However, the dittany is not very common as a garden shrub. On the one hand, this is due to its location requirements, and on the other, it is not easy to propagate. Those who dare to do so will be rewarded with pretty flowers and a tart lemon scent, which the plant exudes, especially when the sun is shining.
It owes the trivial name “burning bush” to its fragrant, volatile, essential oil, which is contained in its flowers and fruits. You can ignite it, when there is no wind, without harming the plant. However, this rarely works outside a laboratory and is therefore not really recommended. In very hot weather, on the other hand, it self-ignites and deflagrates in bluish flames. Unfortunately, this oil is also to blame for sensitive people reacting to contact with painful skin irritations that are reminiscent of burns and are visible for a long time. This so-called photodermatitis is triggered when the affected areas are exposed to UV rays. That being said, all parts of dittany are slightly toxic.
Characteristics of dittany
With suitable conditions, the dittany proves to be an extremely long-lived perennial, which also becomes more beautiful from year to year. The stems, on which the pretty flowers form, reach heights between 80 and 100 centimeters (32 and 40 in). They lignify at the base. The characteristic spicy aroma can be noticed on all parts of the plant.
The green leaves of the burning bush are alternate and pinnate. They are ovate to lanceolate and show tiny black spots on the leaf blade.
The attractive pink flowers of the dittany are zygomorphic, that is, they are assembled of two perfectly mirror-image sides. They appear in terminal racemes from June to July.
After flowering, the burning bush develops star-shaped capsule fruits, which consist of five compartments, each containing two to three small black seeds. As soon as they are ripe, they are thrown out of the inside. Until autumn, however, the fruit remains on the perennial and is often used dried for winter decorations.
Dittany – cultivation and care
When choosing a location, a gardener should think a little more than is generally the case. A dittany thrives very well if it has been left alone over the years and is not exposed to the stress of transplanting. A look at its natural occurrence provides information on where the ornamental shrub feels most comfortable. It thrives best on dry meadows, open spaces with a typical heather character, along sunny borders of woods and in classic wild perennial borders.
- Sunny, sheltered location.
- A warm place in partial shade is tolerated.
- Dry, calcareous soil, well drained.
In principle, a burning bush is suitable as a container plant, provided it is assigned a suitable location and a pot of at least 125 liters (33 gal). If after a while the change to a larger plant container is due to the fact that the previous pot is completely rooted, there is a risk that the dittany will no longer grow.
In addition to lots of sun, this extravagant perennial needs well-drained, calcareous, moderately nutrient-rich and dry to fresh soils, which can also be stony. Acid and waterlogged soils should be avoided. Particularly heavy soil can be loosened and more permeable by adding sand and fine gravel or grit.
- well permeable to water
- rather dry
- pH value: calcareous (8-10)
- moderately nutrient-rich
Like peonies, a dittany should be planted in a place in the garden where it not only gets a lot of sun, but can also grow undisturbed over several years. Once the roots have developed well, it will delight the gardener with its abundant bloom between June and July for years to come. The herbaceous plant is best used in smaller groups of around three plants.
- Time: spring or autumn
- Is somewhat sensitive to unusual ground conditions
- When growing from seeds, use the same soil for cultivation that will later be available in the garden
- Alternatively adjust the garden soil to the substrate in the pot
- If necessary, create drainage or mix soil with sand
- Planting distance: at least 50 centimeters (20 in)
- Protect young plants from snails
- Just water lightly
Burning bushes are a wonderful eye-catcher in the garden by themselves, but they come into their own in beds or borders together with:
A socialization with tall or overgrown neighbors turns out to be unfavorable, since these quickly dispute the space, and also the sunlight, for the rather slow growing dittany. Burning bushes also have a special effect as solitary plants in the perennial border.
The burning bush is a very frugal plant that does not require any significant amounts of water and nutrients. It grows and thrives well on barren and quite dry soils and only needs to be watered in persistent hot or dry periods. The irrigation water should always be applied directly to the root area and not poured over flowers and leaves.
If there is fertilization at all, it is best to use a little compost in the spring. Additional nutrients are not necessary.
It is best to simply let the burning bush grow and only cut it back to about 20 centimeters (8 in) before the new shoot in early spring. Sick or dead shoots should be shortened close to the ground. The herbaceous plant does not tolerate a prune during the growth phase so well. In addition to a wonderful floral display, the dittany also impresses with its fruit stands until late autumn.
- Only prune dittany next spring before the new shoot
- Shorten shoots up to 20 cm (8 in) above the ground
- Thin out dead wood and sick branches close to the ground
Whoever cuts the plant according to this requirement also strengthens the winter hardiness to such an extent that further protection is not necessary. The birds hibernating in the garden also highly appreciate the seeds as a vital source of food.
Although the plant is very rare and therefore has been under nature protection since 1936, it shows itself to be very popular. The dittany has developed two different strategies for propagation. It spreads over short distances by rhizomes, over longer distances by seeds.
Propagation by division
A very uncomplicated method to propagate dittany is by division. However, the root ball is not divided here, as is common with perennials. Rather, the dittany forms rhizomes, which, however, only show up on older plants.
- Time: early spring (before new shoot)
- Dig out the plant widely
- Separate the rhizomes with a sharp knife or spade
- Replant immediately
- Planting depth as before
Propagation by Sowing
After the flowering has been pollinated by insects, a star-shaped capsule with seeds is formed until late summer. When the capsule is ripe, its chambers open explosively and the seeds are thrown out. Ripe seed pods can be harvested and the seeds used for propagation. The capsule should already be dry, maybe a little open. Dittany seeds need cold to germ, so growing from seeds is a lengthy process. Before germination, a cold period is necessary in which the seeds go through a resting phase. Many plants that occur in temperate latitudes have developed this strategy.
For the gardener, this means that he has to stratify (cold treat) the seeds. The seeds can be placed directly in the garden soil and covered with a little soil. Since a sufficiently long cold period is not necessarily guaranteed outdoors, it can also be cultivated in the pot.
- Time: autumn
- Time required: several months
- Conditions: cool, but frost-free, moist
In practice, the seeds are artificially exposed to these conditions. To do this, store them moist in the refrigerator for several weeks. Since the procedure with a moist substrate can easily lead to fungi or other microorganisms, the substrate should not consist of common garden soil or commercially available potting soil. The following are better:
- fine gravel
- alternatively several layers of kitchen roll
The seeds are mixed with the moist, but not wet, substrate or placed between a few layers of kitchen roll and then placed in a plastic bag to protect them from drying out. It is best to keep them in the vegetable compartment of the fridge. During the winter, the hard, shiny black shell swells and slowly opens. From March / April, the pre-treated seeds can then be planted in plant pots or directly in a prepared seedbed.
Optimal substrate for sowing
A burning bush feels just as comfortable in the garden as at the edge of the forest, provided that it finds the ideal conditions there. It starts with the right substrate for sowing.
- Basis: common potting soil
- Expanded clay or pumice (for aeration)
- Clay (for good water flow)
- Lime split (for the pH value)
Not to forget a thick drainage layer in the lower part of the pot. This means that too much moisture does not accumulate in the substrate. A fine layer of sand is now placed on the substrate mixture. It prevents the seeds from sinking too far down. Only then is plenty of seed applied, because not every seed really germinates.
Since the dittany needs dark to germ, another thin layer of sand and ultimately a little fine gravel follow. This prevents the seeds from being rinsed out during watering. Packed in a transparent plastic bag or covered with a glass pane, the pot is placed in a warm place without direct sunlight in the house. Up to 180 days can pass before germination.
Diseases and pests
Dittany is extremely robust with optimal soil and site conditions and is only slightly susceptible to diseases or pests. However, snails can do great damage. Young plants in particular are very popular with slugs from spring to autumn.
Dittany is used to cold temperatures in winter. It tolerates temperatures down to -20 °C / -4 °F without being significantly damaged. Therefore, no protective measures are necessary before the onset of winter. Faded shoots and ripe fruit can remain on the plant until spring. They not only offer a wonderful eye-catcher in the otherwise bare winter bed, but also serve as a food source for birds.
In contrast, appropriate protection is essential for potted plants. In the bucket, the roots are particularly susceptible to frost damage, to counteract this, wrap the planter with jute, fleece or bubble wrap. The pot should not stand directly on the ground, but rather a little higher, it is best to place it on a wooden pallet or pieces of wood.
Use in the garden
As already mentioned, the dittany is an attractive plant for sunny beds and borders. Other perennials such as the iris (Iris) or the hellebore (Helleborus) are ideal planting partners. The scented plant also comes into its own in prairie gardens, together with prairie perennials and ornamental grasses.
The best known and perhaps also the most beautiful dittany variety on the market is Dictamnus albus ‘Albiflorus’, which gives every bed an elegant touch with its bright white flowers. The flowers of ‘Purpureus‘ are a little stronger pink than those of the species. The variety Dictamnus albus var. Caucasicus is similar to the species, but is slightly larger.