Botanists have classifiedbegonias(Begoniaspp . ) into three major group based on their root structure : hempen , rhizomatous and tuberous . The begonia , with over 1,000 different coinage , develop in the tropic . Some begonia extend not only delicate , coloured blossom but also decorative foliage . Begonias thrive year - round of drinks in U.S. Department of Agriculture plant hardiness zones 7 to 10 . Although begonia can be fun to grow , they are susceptible to a number of pests and disease .
Bacteria and Blight
Bacterial folio spotis one of the most common diseases affecting all varieties of begonias . Leaves develop humble spots with yellow halos . The spots get grim in colouration and buoy up over time . leave fail and sink . In advanced stages , the disease causes systemic transmission and plant life wilting . Botrytis leaf blightis a fungus make tan spot that apace magnify and cover the leafage . moth-eaten gray or green fungus may also come along . This fungus prosper in cool temperatures and eminent humidness . Rhizoctonia blightstarts at the stem of works stem next to the soil . Look for reddish - chocolate-brown fungus like a spider World Wide Web . southerly blightaffects the whole begonia plant but is most seeable on leaves . This blight causes the growth of coarse white fungus in a rooter - like pattern . Destroy all diagnostic plant involve by bacteria or blight .
Mildew and Rot
Powdery mildewcan feign leaves , blossoms , or stem . The mildew look like whitened powder and cause the rudimentary tissue paper to die . Pythium rotis the likely perpetrator if plants droop and break at the soil occupation . This disease typically comes from contaminated soil . Look for black decaying spots on stem turn . Rhizoctonia crown rotis similar to Pythium decompose , as it stimulate stem to decay at the dirt line . A fungal internet grows between the radical and soil . Destroy all symptomatic plants affected by mold or decomposition .
Insects and Pests
In accession to bacterial and fungous attacks on begonias , a overplus of insects and gadfly can also do problem . If you notice a post of sooty sinister mold in conjunction with scrawny maturation , aphids and mealy bugsmay be to fault . Mitescause new leaves to cup downward and pucker . Snails , slugs and thripsfeed on leaves , ensue in unorthodox hole , marred and calloused foliation . Whitefliesturn leaves yellow and also pass on behind black sooty mould muscae volitantes . Thelarvae of fungus gnatsproduce web on the territory ; they also damage origin and leaves advert the ground . Caterpillarsleave their alimentation hole and excrement behind . Foliar nematodescause red pigmentation and brown point on leave , while other nematodes get knots to get on root . Aster Yellowsis a disease caused byleafhoppersthat results in spindly growing and yellow vein on young begonia leaves .
Remove any discredited leaves or halt and cover plants affected by dirt ball pests with a horticultural vegetable oil and baking sal soda mix . coalesce 1 tablespoon horticultural oil and 1 tablespoon baking soda with 1 gallon of piddle . Spray each plant , covering both the topside and underside of leave of absence . Spray twice the first hebdomad , then value whether the plant is improving . In the causa of severe infestation , destroy the plant .
Defense Protocol
Pests and diseases that attack begonias may be forefend by follow a defense protocol .
soundly spray plants weekly with the horticultural oil and baking sodium carbonate mixture . This commixture serves as anon - toxic deterrent to fungal , bacterial and pestilence - refer problemswith begonia .
Avoid overhead lacrimation that wets leaves , and insure piddle does not splash from plant life to implant .
Wash your hands frequently when handle plants .
Sterilize horticulture tools by soaking in 70 pct chafe alcohol for one minute . Do not rinse off . Air ironical .
Use only use disease - free plants for cutting and propagation .
Use only pasteurised soil and planting medium .
