Gadenin日本語Get the appA summer grower that moves with the seasons
Pachypodium is a genus of spiny succulents in the dogbane family, native to southern Africa and Madagascar. Most species grow actively from spring through fall, flower in spring or early summer, and drop their leaves in late fall to rest through winter. The more sun they get while growing, the thicker and more compact the trunk becomes.
They are tender, though, and frost damages the trunk. Rather than keeping the pot in one place all year, plan to move it: outdoors in full sun for the growing season, indoors to a bright window for winter.
| Season | What the plant is doing | Where to keep it |
|---|---|---|
| Mid to late spring | Leaves open, flowers appear | Outdoors in sun, under cover from rain |
| Summer | Growing fast | Full sun with good airflow, out of prolonged rain |
| Early fall | Leaves start to yellow | Outdoors in sun; bring in on cold nights |
| Late fall to early spring | Leafless and dormant | Indoors at a bright, frost-free window |
Bring the plant in once night temperatures start dipping below about 50°F (10°C). Species from low elevations are the most tender, so move them first.
Full sun under cover while it grows
From spring through early fall, an outdoor spot with full sun and moving air grows a far sturdier plant than a windowsill. The one thing to avoid is long spells of rain. A pot that stays wet for days invites root and trunk rot, so a sunny spot under an eave, a porch roof, or a balcony overhang is ideal.
- Find sun that rain cannot reach Choose a sunny spot under an overhang so the pot does not sit soaked through rainy weeks.
- Lift the pot off hot paving Set the pot on a bench or stand so air moves under it and the drainage hole is never blocked by a hot, wet surface.
- Turn the pot now and then Rotate the pot every few weeks so the trunk does not lean toward the light and all sides get sun.
Harden off plants that wintered indoors
A plant that spent winter indoors, or one bought from an indoor display, can scorch if it goes straight into hot summer sun. Leaves bleach and the trunk can show tan, corky scars that never fade. Move it outside gradually over a couple of weeks.
- Start in bright shade For the first several days outdoors, keep the plant in bright shade with good airflow so it adjusts to outdoor conditions.
- Move to morning sun Once new leaves are opening, give it morning sun only and watch for pale or brown patches on the leaves.
- Finish in full sun After one to two weeks with no damage, move it to full sun, where it will handle the strongest summer light.
How much cold each species takes
Cold tolerance varies between species. Kept dry and out of frost and wind, most survive somewhere between the mid 30s and the upper 40s °F (2 to 8°C). Plants kept above about 50°F (10°C) may hold some leaves and keep growing slowly; for a true dormant rest, staying above about 41°F (5°C) is a safe target.
Highland species tend to be hardier and lowland species more tender. If you are not sure which you have, treat it as tender and bring it in early.
| Species | Approximate survival minimum (dry) | Relative hardiness |
|---|---|---|
| P. bispinosum | 36°F (2°C) | Fairly hardy |
| P. saundersii | 37°F (3°C) | Fairly hardy |
| P. gracilius, P. brevicaule, P. eburneum | 41°F (5°C) | Average |
| P. densiflorum, P. lamerei, P. horombense | 46°F (8°C) | Tender |
These are guideline figures for plants kept frost free with dry soil. In wet soil, roots can rot at temperatures well above these.
A bright, steady spot indoors for winter
Indoors, give the plant the sunniest window you have. Even leafless, it benefits from light, and plants kept bright through winter leaf out more evenly in spring. Window glass gets cold on frosty nights, so on the coldest nights move the pot back into the room.
- Use a south or east window Place the pot where it gets direct sun for part of the day. Light keeps the trunk firm and speeds new growth in spring.
- Pull it back on frosty nights On very cold nights, move the plant away from the glass or close heavy curtains between the plant and the window.
- Keep it out of heater drafts Hot air from vents dries the trunk and encourages spider mites. Choose a spot with steady temperatures away from heaters.
New and imported plants need extra care
Because these plants dislike cold, spring through summer is the best time to buy one. A plant bought in winter often has few established roots and struggles in a new home. Imported plants in particular are most often lost in their first winter, so give them a warmer margin than the guideline figures.
- Keep the first winter warmer For a plant whose roots are not yet established, aim for around 50°F (10°C) through its first winter rather than the bare minimum.
- Check the trunk by touch Press the base of the trunk gently every few weeks. It should stay firm. Softness suggests rot and needs attention right away.