[Ebook Việt Hoá] The Instant Guide to Healthy Houseplants: Euphorbia obesa (Living baseball, Gingham golf ball)

English

When a plant has a name like obesa, it should come as no surprise that it is plump. Its common name, living baseball, comes not just from its shape but also from its “stitching” small knoblike tubercles that appear along 8 distinct vertical ridges. The plant also has transverse bands of fine purple lines that set off its gray-green coloring. Male and female flowers appear on separate plants and are reminiscent of the true flowers of another Euphorbia, the Christmas poinsettia. (These flowers are the knobby growths that appear in the center of the plant’s colorful bracts.) Obesa male plants tend to be pear- shaped; female plants are more rounded. 

Light 

Needs bright light and will tolerate several hours of direct sunlight a day, but use a curtain to shield plant from midday sunlight in hottest weather. 

Temperature 

Ideal temperature range year-round is 70-80°F (21 -27°C) during the day and 10 to 15 degrees cooler at night. Plant tolerates higher temperatures if good air circulation is provided. 

Repotting 

Remove plant from pot in late winter or early spring before growth becomes active. If soil seems taken over by roots, repot plant in pot one size larger. If roots have not filled pot, repotting is not necessary. 

Humidity 

No special treatment is necessary. 

Soil 

Use a sandy, well-drained soil mix (such as equal parts garden loam or all-purpose potting soil, peat moss and sand). Use a pot that provides good drainage. 

Feeding 

In spring and summer, feed every 2 weeks with any house-plant fertilizer at half the manufacturer’s recommended strength. Do not feed in fall and winter. 

Water

In spring and summer, keep soil evenly moist to slightly dry at the surface. Do not leave pot standing in water for more than an hour. Water less often in fall and winter (about once a week, or a few days after the soil surface starts to dry out). 

Propagation 

Plant rarely produces offsets suitable for propagation. For seed production, both male and female plants are necessary. At flowering time, use a small camel-hair paintbrush to remove the grainy yellow pollen from the male plant’s flowers and dab it onto the slightly sticky stigmata of the female plant’s flowers. When seeds are ripe, sow to a depth of their own thickness in a sandy growing medium. If kept constantly warm (about 70°F – 21°C) and moist, baby “base- balls” begin to appear above the soil in about a month. 

What Goes Wrong 

• Softened, translucent or dried spots on body of plant: Sunscald or too-strong fertilizer. Protect plant from strong midday summer sunlight and provide good air circulation when temperature is high. If too much fertilizer has been applied, flush soil with clear water several times within a few hours. Damaged areas will remain discolored, but normal growth may resume. 
• Plant becomes elongated, growing as a column instead of in a ball or pear shape: Poor light or natural aging. Move plant to a spot that gets brighter light, including some sunlight. If compact new growth appears, poor light was probably the cause of the elongation. If growth continues as before, natural aging is likely the cause. 
• Plant flowers but produces no seeds: Natural when plant is not placed next to plant of opposite gender. Purchase plant of opposite gender and pollinate female flowers, using small camel-hair paintbrush. (See Propagation for details.) 
• No new growth in spring; plant body soft; on close examination, black tissue found at plant base: Black rot, from overwatering in fall and winter. Cut away infected (discolored) roots and body parts. (Plant will profusely bleed white milky juice that could cause a toxic reaction in humans; avoid getting juice on skin). If remaining healthy tissue seems promising as a cutting, allow it to dry for 24 hours, then snuggle the base in moist sand. Keep warm in bright light. Rooting should occur in 4 to 6 weeks. If it does not, discard