Dieffenbachia

Quick facts

Part sun or part shade or shade · medium water · well-drained soil · 18 in apart (12 to 30) · transplant or cuttings or division

Nothing is open today. Spring transplanting opens 6 months, Mar 15 to Sep 15.

1. Transplant Mar 15 – Sep 15 Opens in 175 days
   Best timeSpring
   Indoors year-round; pot up cuttings and repot in the warm half of the year, when roots move fastest and a cut cane heals quickly. Do not plant it outdoors where children play, and note that it has escaped into disturbed woodland in south Florida and Puerto Rico.

Frost here: last around Apr 10 (Mar 27 to Apr 24 most years), first around Oct 25. Zone averages, your own yard may run a week or two either way.

One stage to settle in, then two that repeat each year. Windows are typical; your zone and weather move them.

1. In the garden, counted from transplant
2. 1

   Settling a new plant or rooting a cane

   Day 0 to 45

   • ProtectChoose the spot for safety before you choose it for looks
     This is the first decision, not the last one. A dieffenbachia at floor level in a wide pot puts a big soft chewable leaf exactly at toddler and dog height, and it is the plant in this family most likely to send someone to an emergency room. Put it on a plant stand or a high surface, in a room small children and animals are not left alone in - or choose a pothos instead.
   • WaterPot in a chunky mix and keep it evenly moist, not wet
     Use ordinary potting mix opened up with a couple of handfuls of perlite or orchid bark, in a pot with drainage holes barely wider than the root ball. Water it in thoroughly once, let the excess drain, and then keep the mix lightly moist rather than either soggy or bone dry. New plants are lost far more often to a full saucer than to neglect.
   • InspectBright indirect light, and warmth above 60°F
     A few feet back from an east or north window suits it. Direct sun bleaches and burns the pale variegation within days, and deep shade makes the leaves come out plainer and further apart. Dieffenbachia is also the least cold-tolerant plant on the shelf: below about 60°F it stalls, and a cold draft from a door in January can collapse a whole side of the plant.

   Watch for

   • A pot at floor level within reach of toddlers or pets
   • Scorched bleached patches from direct sun
   • A cold draft from a door or a single-glazed window
3. 2

   Leaf and cane growth

   Mar to Oct, every year

   • WaterWater when the top inch is dryweekly
     Push a finger into the mix; water thoroughly when the top inch is dry and empty the saucer afterwards. Dieffenbachia wants more consistent moisture than a pothos or a ZZ plant and still rots if it sits wet. In winter the plant nearly stops and the gap between waterings roughly doubles - check the mix, not the calendar.
   • PruneGloves, eye protection and a covered surface before any cut
     Cutting a dieffenbachia releases more sap than anything else on the shelf, and that sap is the dangerous part. Wear gloves and, honestly, glasses; work over newspaper rather than a kitchen counter; wipe the blade afterwards; wash your hands before touching your face. Bag the cuttings straight away rather than leaving them where a curious animal can find them.
   • InspectWipe the leaves and turn the pot
     Those broad flat leaves collect dust that noticeably dulls them and cuts the light the plant can use. Wipe both sides with a damp cloth every month or two, wearing gloves, and give the pot a quarter turn each time you water so it grows upright instead of leaning toward the window.
   • FertilizeFeed lightly through the growing season
     A balanced liquid houseplant fertilizer at half the label strength, roughly monthly from spring to early autumn. Stop entirely in winter - growth slows to nothing and leftover fertilizer salts build up in the pot and scorch the leaf edges. Flush the pot through with plain water once or twice a year to clear them.

   Watch for

   • Lower leaves yellowing and dropping, leaving a bare cane
   • Pale washed-out variegation from too much direct sun
   • Brown leaf edges from dry air or fertilizer salts
   • White cottony mealybugs where the leaf sheath wraps the cane
4. 3

   Winter slowdown

   Nov to Feb, every year

   • WaterWater much less in winter
     Short days and cool rooms slow the plant almost to a stop. Keep to the summer schedule and the roots rot; expect the gap between waterings to roughly double from November to February, and let the top inch or two dry before each one.
   • ProtectKeep it warm - this is the coldest-sensitive plant on the shelf
     Dieffenbachia is damaged below about 55°F, well before frost. Leaves against a freezing windowpane blacken overnight, and a spot beside a door that keeps opening in January will collapse whole leaves. Move the pot into the room for the winter, away from glass and away from the cold draft at floor level.

   Watch for

   • Blackened or water-soaked patches after a cold night
   • Sudden collapse of several leaves at once (cold, not disease)
   • Fungus gnats in mix kept too damp

Watch out for

6 to know. 2 are high-risk: Dumb Cane Poisoning (mouth and throat swelling), Root Rot from Overwatering. 6 are active in September.

Good & bad neighbors

First rule: keep Sago Palm apart. Named as a correction, not a planting rule.

Varieties · 6

You pick one when you add Dieffenbachia to your garden. Its days to maturity set your harvest window.

• Compacta

  Good first pick

  Dense low clump of mid-green leaves with cream speckling along the midrib, under 2 ft.

  compactbushy

  A dwarf, densely branching form that stays under two feet and holds its lower leaves far longer than the tall kinds, so it goes bare-caned much more slowly. The easiest dieffenbachia to keep looking good with no intervention, and small enough to sit safely on a high shelf rather than the floor.

• Camille

  Broad leaves with a wide creamy-white centre and a narrow deep-green margin, on a bushy plant to about 3 ft.

  compactpale-centrecommon

  The dieffenbachia most garden centres sell: compact and bushy at two or three feet, with broad leaves that are almost entirely creamy-white in the centre and edged in mid green. The pale centre means less chlorophyll, so it grows a little slower and scorches faster in direct sun than the darker kinds. Same sap, same rules - compact does not mean mild.

• Tropic Snow

  Very large dark green paddle leaves marbled and feathered with cream along the side veins, on stout canes.

  largevariegatedvigorous

  A big, vigorous old cultivar reaching five or six feet indoors, with large dark green leaves heavily feathered in cream along the veins. This is the one that becomes a floor-standing specimen, and therefore the one most often kept at exactly the height a toddler meets it - give it a plant stand or a room where it is out of the way.

• Reflector

  Dark green leaves mottled all over with irregular chartreuse and cream blotches, to about 2 ft.

  patternedcompactneeds-brighter-light

  A striking modern cultivar with dark green leaves dappled in irregular pale-green and cream blotches like camouflage, on a compact plant. It wants brighter indirect light than the plainer types to hold the pattern, and it is a little more sensitive to cold and to being kept wet.

• Tropic Marianne

  Pale creamy-yellow leaves with fine green veins and a thin green edge, on a compact plant.

  palecompactlight-sensitive

  Almost the reverse of the usual pattern: leaves that are predominantly pale yellow-cream with only a thin green margin and green veining. Very little chlorophyll means slow growth, a real need for good indirect light, and rapid scorching in any direct sun - the least forgiving of the common cultivars.

• Amoena / Tropic Rain

  Large deep-green leaves with bold irregular cream striping along the veins, on thick upright canes to 5 ft.

  largeclassicvigorous

  The classic large-leaved dieffenbachia of mid-century offices and lobbies, with deep green leaves striped irregularly in cream and a thick upright cane that eventually leans under its own weight. Robust and long-lived, and the type that most needs beheading every few years once the lower cane goes bare.