(dik-TAM-nus  AL-bus)

General Information:

Dictamnus albus always makes a big splash in the garden when it is flowering and even when it is not flowering it is a very interesting plant with good leaf structure.  Even the star-shaped seed heads are interesting. So why is this plant not seen more in gardens? It is very slow growing and I think it costs nurseries too much to get it to a saleable size. Fashions have changed and this fantastic plant has been left behind in favor of more modern plants. That is a real shame since few garden plants will match the presence of a mature Dictamnus.

Dictamnus albus ‘Purpureus’: photo by Robert Pavlis

The most common name is gas plant, but some people also call it burning bush, dittany, and fraxinella. The name gas plant refers to the of fragrant, flammable oils produced both during flowering, and while it produces seeds. The fragrance is lemony and quite pleasant.  If you touch the plant, you will feel the oils produced. Some, consider this to be the burning bush referred to in the bible.

Is the gas plant really flammable? Have a look at this video.

https://www.youtube.com/watch?v=OH7u4xFmpP0

Before you go and touch this plant you should be aware that it causes phytophotodermatitis (ie skin reaction) for some people where exposure to sun produces blisters. I don’t have this problem and most people don't.

Dictamnus albus ‘Purpureus’: photo by Robert Pavlis

The gas plant has a long, deep tap root which makes it very drought tolerant but also difficult to divide or move. It is best to leave the plant where it is, and grow a new one from seeds. But even this can be a bit tricky. When the seeds are ripe, they are shot out of the seed capsule as soon as you touch them. It is best to bag seed heads and wait until they drop into the bag.

Seedlings grow slowly, but are not difficult to raise. The plants are quite tough and should flower in 3-4 years. Once established, it will last a very long time.

Dictamnus albus 'Alba': photo by Robert Pavlis

Available in three main colours, pink with stripes (D. albus ‘Purpureus’), white (D. albus ‘Alba’) and a much less common red (D. albus ‘Rubra’). I looked for a picture on the internet for rubra and could not find one. Several nurseries sell a so-called rubra, but the pictures are clearly that of Purpureaus. Does a red one really exist?

Website administrator's comment: The Royal Horticultural Society is the primary reference used by ORG&HPS for confirming the name of cultivars. RHS lists  D. albus var. albus and D. albus var. purpureus indicating they are varieties, not cultivars. In addition, they specify that D. albus 'Rubra' is a synonym for D. albus var. purpureus.  See RHS database

Life Cycle: perennial

Height: Plant is 60cm (2 ft) tall with the flower spike adding 30 cm (1 ft)

Bloom Time: Mid summer

Natural Range: Europe, North Africa and much of Asia

Habitat: open woodland

Synonyms:  Dictamnus fraxinella, Dictamnus caucasicus

Cultivation:

Light: full sun

Soil: fertile and humusy – but not fussy

Water: drought tolerant once established

USDA Hardiness Zone: 3 – 9,  prefers cool climates

Propagation: seed, division with care

Seedex availability (ORG&HPS annual Seed Exchange): usually

 (del-oh-SPUR-muh  kon-JES-tum)

General Information:

Delosperma congestum is a cold hardy succulent that makes spectacular flowers that glisten in the sun. It is an alpine plant that originates from the mountains of South Africa.

Delosperma congestum :photo by Robert Pavlis

The common name for Delosperma is hardy ice plant, and this species is known as the congested ice plant. The name ice plant may be due to fact that the leaves are covered with papillose tissue which reflects light, giving the leaves frost-covered look.

This plant is rated for zone 5 and is commonly found in nurseries in S. Ontario. Unfortunately, it is not a reliable plant here. In drier zone 5 areas, such as the mid-western US, this is a reliable perennial but in the wetter eastern regions of North America, it seems to die out in winter, even when grown in a fast draining sandy substrate.

Delosperma congestum :photo by Robert Pavlis

I have had very little luck overwintering this plant in the garden, but it is easy to grow in pots and overwinter in a cold fruit cellar. In fall, reduce watering and allow it to dry out. A light frost will not harm the plant. Before the real cold weather sets in, take the pot into the basement and store it cold. Water it once a month or so. Even in complete darkness, Delosperma will remain green. In spring bring it outside and condition it for full light.

A cultivar, named ‘Gold Nugget’ or ‘Golden Nugget’, exists and I suspect most plants in gardens are this cultivar. There is also a ‘White Nugget’ with white flowers, but it is a cultivar of D. basuticum. I have seen a listing for D. congestum ‘Alba’.

Delosperma congestum :photo by Robert Pavlis

Life Cycle: perennial

Height: 8cm (3in)

Bloom Time: summer

Natural Range: South Africa

Habitat: dry alpine regions

Synonyms:  none

Cultivation:

Light: full sun

Soil: well draining

Water: drought tolerant

USDA Hardiness Zone: (4?)(5?) 6- 9

Propagation: seed, division

Seedex availability (ORG&HPS annual Seed Exchange): rare

(sim-buh-LAR-ee-uh mur-AH-liss)

General Information:

Cymbalaria muralis is a very short ground cover that grows in sun or shade. It makes a nice matt of leaves and blooms most of the summer. In mid-June it produces the most flowers to make a nice display. The flowers are very interesting but so small that you need to get up close to appreciate their detail.

Cymbalaria muralis ; photo by Robert Pavlis

Its common names include Kenilworth ivy and ivy-leaved toadflax. It is known for its ability to grow in small cracks in walls. This plant spreads a bit too much for a rock garden, but it works great in a bed containing larger plants. In such a situation it covers the ground under other plants and peeks out in the spaces between the other plants. It works especially well under shrubs. Larger plants will outcompete Cymbalaria muralis.

C. muralis spreads by runners which root along nodes as they grow. It is described as a vine, but it is so short that it does not grow up very well. It is mostly a ground hugging spreader. It’s propagation by seed is unusual. The flower stalk is held above the leaves moving towards light. Once the flower is fertilized the flower stalk becomes pendent moving away from light. This helps force the seed into dark crevices on the ground or in rock walls.

Cymbalaria muralis ; photo by Robert Pavlis

Cymbalaria aequitriloba is a very similar species but the plant and flowers are smaller. One description said that the yellow colouration in the throat of the flower is not present in this species, but is present in C. muralis. C. aequitriloba may have slightly hairy leaves.

Life Cycle: perennial

Height: 5 cm (2 inches)

Bloom Time: May to September

Natural Range: Mediterranean Europe

Habitat: rock crevices, along footpaths

Synonyms:  Linaria cymbalaria

Cultivation:

Light: sun to shade, prefers part-shade

Soil: well draining

Water: drought tolerant

USDA Hardiness Zone: 4-8

Propagation: seed, division

Seedex availability (ORG&HPS annual Seed Exchange): rarely