Dictamnus or Gas Plant

Family Rutaceae. Six species are known, occurring in the temperate and subtropical regions of Eurasia.

Perennial rhizomatous herbaceous plants up to 90 cm tall. Leaves are imparipinnate, similar to ash leaves, hence its second name. Large white, pink, reddish, or lilac flowers are arranged in racemose inflorescences. The fruit is a capsule, with black, shiny seeds. They contain large amounts of essential oils, released during the seed ripening period. Two species are common in cultivation: the white and the Caucasian. The others are practically not found in our gardens.

In nature gas plants most often grow in light forests, at forest edges, among shrubs, or on rocky and grassy slopes. The plants are very hardy in cultivation, performing well in both full sun and partial shade, preferring dry sites and any cultivated soils. They can live for a very long time in one place.

Location: they reach their best development in open, sunny sites; slight shading does not significantly affect their growth.

Soil: they avoid wet soils, growing well on any cultivated, sufficiently fertile soils containing lime.

Care: standard. Weeding, loosening (or better mulching) the soil, occasional watering and fertilizing (preferably with mildly alkaline fertilizers).

Propagation: by seeds, division of the clump, and cuttings. Seeds ripen in August; if not monitored, the fruits split and the seeds are dispersed up to a radius of 3 m. Sow immediately after collection in the open ground. When sown in autumn, some seeds germinate only after a year. Seedlings are pricked out at a spacing of 15 cm, grown on for 2–3 years, then planted in their permanent place; they flower in the 3rd–4th year. Division of the clump is carried out in spring or autumn. Transplanting and division in summer lead to the death of the plant. The divided parts are planted 35–40 cm apart and watered abundantly. They can grow in the same place for 8–10 years. Cuttings are taken from young, non-woody shoots; for better rooting treatment with heteroauxin is required.

Use: in solitary and group plantings, in mixed borders. Gas plants are good in rockeries, which corresponds to their nature, as in their native range they settle among stones. They can also be grown on fertile beds, where they will decorate the central part of the flowerbed, away from paths. Often gas plants are used in mixed flowerbeds composed of dry-loving plants such as daylily, heuchera, liatris, kachim, statice, monarda and the like. When cut, they last 3–4 days in a vase.