Despite having the most amazing cobalt blue flowers and being a versatile garden shrub, Pycnostachys urticifolia (Blue Boys) is not well known nor more widely grown. Although a little frost tender, if planted in a sheltered spot it will survive the Gauteng winters with little mishap, much like Plectranthus (Spurflowers) do.
- Pycnostachys from the Greek words ‘pyknos’ and ‘stachos’ and translates to ‘dense spike’ or ‘dense corn ear’, referring to the flower spike.
- urticifolia – having leaves like those of a nettle (Urticea).
Common Names: Blue Boys (Eng), ystervarksalie (Afr), gogodza (Ven), amadata and unkungwini (Zul).
Size: 1 – 2 m by 1 – 1.5 m.
- Stunning cobalt blue flowers are borne on rounded, pyramid like flower spikes.
- Flowers open in rows around the cone together, starting from the base of the spike and progressively opening closer to the terminal point.
- Usually two or three rows of flowers open at any time, with more showing their colour before opening.
- As the older flowers die and drop off, they leave reddish spines at their base on the cone.
- The spiky ‘cones’ remain on the plant long after the flowers have finished and give rise to the Afrikaans name ‘ystervarksalie’ (Porcupine Salvia).
- New flower spikes constantly form during the flowering period.
Flowering Months: Mar to Aug, but frost may stop the flowering.
Fragrance: Crushed leaves are aromatic.
- Evergreen to partly deciduous.
- Has simple, green, oval leaves with scalloped margins.
Thorns: No thorns.
- Seeds are contained within a capsule within the calyx.
- Stems are sparsely hairy.
In the Garden:
- Pycnostachys urticifolia is an attractive plant suitable for the back of informal borders or beneath trees.
- It is frost tender and may be cut back if exposed to too much cold.
- It may be planted individually but looks best when planted in groups of three or more plants.
- It is equally at home in full sun or dappled shade beneath trees, but tends to be smaller and more compact in full sun.
- It is a good pot plant.
- A wildlife friendly shrub, attracting insects, bees and butterflies.
- A quick growing shrub, flowering within the first year of been planted out.
Soil Needs: Plant in ordinary garden soil with compost, 2:3:2 and bonemeal.
- A low maintenance plant.
- Mulch with a layer of compost once or twice a year and feed with organic 3:2:3 and bonemeal.
- Plant in a sheltered position.
- Cut back in spring after the threat of frost is past.
Cold Hardiness: Semi-tender.
- Likes regular water in summer but will endure some drought.
Light Requirements: Full sun or partial shade.
- Insect-eating birds are attracted to the insects that eat the leaves.
Insects and Butterflies:
- Flowers are visited by many insects and adult butterflies.
- Host plant to the larva of the Gaudy Commodore
- Also larval host of 1 moth species.
- No records of being used as a medicine.
Notes of interest:
- Pycnostachys urticifolia is grown in gardens in the USA where it is called witches hat.
- Although looking impossible to pronounce, it is in fact quite easy, ‘Pick no stack us’.
- Occurs naturally in the EC, KZN, Swa, M, L, G and Zim.
- North of southern Africa its range extends into Malawi.
- In bushveld, grasslands and in forest margins.
- Often in marshy conditions or along stream banks.
© Malcolm Dee Hepplewhite & Witkoppen Wildflower Nursery, (Text and Photographs) 2012 & 2018