Pachypodium geayi
| Light | Bright light to full sun; loves as much as you can give it |
|---|---|
| Water | Regularly in active growth; keep dry during the leafless winter rest |
| Soil | Very free-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep warm; protect from frost, minimum around 10 °C; USDA zones 10–11 |
| Propagation | Seed (the reliable method) |
| Toxicity | Sap can irritate skin, and all parts are toxic if ingested (the milky latex typical of Apocynaceae); keep away from pets and children |
Pachypodium geayi is a tall, tree-like pachycaul succulent from south-western Madagascar, instantly recognisable by its slender, spine-armoured silvery-grey trunk topped with a crown of long, narrow leaves. It closely resembles the more familiar P. lamerei (Madagascar palm) but is distinguished by its narrower, felty grey-green foliage and reddish leaf midribs, giving mature plants an elegant, palm-like silhouette. It belongs to the genus Pachypodium in the dogbane family, Apocynaceae.
Description
Pachypodium geayi is one of the larger members of its genus, growing over time into a small tree several metres tall in habitat, though it stays far more compact in cultivation. The stem is a stout, silvery to grey-brown column, usually unbranched when young and studded with clusters of stiff spines arranged around the leaf scars. Beneath the waxy surface the trunk stores water, letting the plant ride out long dry periods.
The leaves are the plant's most distinctive feature: long, narrow and strap-shaped, covered in fine hairs that give them a soft, felty grey-green appearance, often with a paler or reddish midrib. They cluster at the growing tips, and the plant sheds them during its dry-season rest, leaving a bare, sculptural trunk.
Mature specimens produce white flowers at the crown, though flowering is uncommon on younger container-grown plants.
Distribution and habitat
The species is endemic to the arid south-west of Madagascar, where it grows in dry, spiny thicket and open bushland on sandy or stony ground. This is a hot, seasonally dry environment with a long rainless period, and the plant's swollen water-storing trunk and deciduous habit are adaptations to those conditions. As with all wild Pachypodium, habitat pressure makes nursery-propagated plants the responsible choice; the whole genus is listed under CITES.
Cultivation
Pachypodium geayi is a rewarding, architectural plant that asks for warmth, light and sharp drainage. Grow it in a very free-draining, mostly mineral mix and give it the brightest position you have — full sun suits it, and too little light produces weak, etiolated growth. Water regularly while it is in leaf and growing actively through the warm months, always letting the mix dry out between waterings.
The key to keeping this species is respecting its winter rest. As days shorten and temperatures fall the plant drops its leaves; at that point cut watering right back to nearly nothing and keep it warm and dry. Cold, wet compost is the quickest way to lose a plant to rot. Never let it sit below about 10 °C. See Watering and Repotting for general technique.
Propagation
Seed is the standard and most reliable method. Fresh seed sown onto a warm, gritty, mineral surface and kept lightly moist and humid germinates well, and seedlings grow reasonably quickly given heat and light. Cuttings are difficult and rarely successful, so vegetative propagation is uncommon. See Propagation — seed for a full walkthrough.
Common problems
- Rot — the commonest killer, almost always from watering during the cold or dormant season, or from a mix that holds too much moisture; the trunk goes soft and discoloured.
- Etiolation — insufficient light causes weak, stretched growth and widely spaced leaves; give it as much sun as possible.
- Leaf drop out of season — sudden cold, drought stress or a move can trigger early leaf loss; often the plant simply re-leafs when conditions improve.
- Pests — mealybugs (white fluff at the leaf bases and crown) and spider mites (fine webbing, stippled leaves) are the usual offenders. See Pests and diseases.
See also
- Pachypodium — the genus overview
- Pachypodium lamerei — the similar, more common Madagascar palm
- Soil and potting mix · Watering · Propagation — seed · Repotting · Pests and diseases