What to sow, grow, harvest and scout for this month, north and south of the equator. May is spring in the north and autumn in the south.
Typical sowing and harvest windows for broad climate zones, for planning and study. Inside every zone the real dates move with latitude, altitude, rainfall onset, irrigation and variety, sometimes by a month or more. Your national crop calendar, extension service or seed supplier decides; this page tells you what to be thinking about.
Temperate north
Europe, North America, northern China, Korea and Japan, Central Asia · spring
Sow and plant now
Growing: manage and protect
Harvest now
- Alfalfa · cut several times a season
Scout for
- Black cutworm on Maize, Cotton, Potato, Tomato, Cabbage, Sugar beet, Sunflower, Soybean, Onion & shallot · favoured by: Weedy fields before planting, reduced or no tillage with crop residues, low-lying fields that flooded earlier…
- Beet armyworm on Sugar beet, Cotton, Tomato, Onion & shallot, Cabbage, Soybean, Alfalfa · favoured by: Hot, dry weather; weedy fields and field edges; large areas of host crops; and broad-spectrum sprays that…
- Egyptian cotton leafworm on Cotton, Alfalfa, Maize, Tomato, Potato, Soybean · favoured by: Warm temperatures, continuous host crops such as Egyptian clover before cotton, irrigation, and heavy…
- Sclerotinia white mould (stem rot) on Soybean, Rapeseed, Sunflower, Potato, Tomato, Cabbage · favoured by: Frequent susceptible crops in the rotation, dense canopies and narrow rows that keep the soil surface moist…
- Barnyard grass on Rice, Maize, Soybean, Cotton, Sugar beet · favoured by: Direct-seeded rice (especially dry-seeded) with no standing water early on, poor land levelling, shallow or no…
- Cotton bollworm (Old World bollworm) on Cotton, Tomato, Maize, Soybean, Sunflower · favoured by: Warm, dry weather; a landscape with a succession of flowering hosts (for example maize, sorghum and chickpea…
- Green peach aphid on Potato, Sugar beet, Rapeseed, Tomato, Cabbage · favoured by: Mild winters (earlier and larger flights), warm springs, lush crops with high nitrogen, protected cropping and…
- Stem rot of groundnut (southern blight) on Tomato, Sugar beet, Potato, Soybean, Onion & shallot · favoured by: Hot, humid weather; light sandy soils; undecomposed organic matter at the soil surface; soil thrown onto plant…
Mediterranean and dry north
The Mediterranean basin, North Africa, the Middle East and West Asia, California · spring
Sow and plant now
Growing: manage and protect
Harvest now
Scout for
- Black cutworm on Maize, Cotton, Potato, Tomato · favoured by: Weedy fields before planting, reduced or no tillage with crop residues, low-lying fields that flooded earlier…
- Broomrapes of vegetables and legumes (branched, Egyptian and crenate broomrape) on Tomato, Faba bean, Lentil, Potato · favoured by: Repeated cropping of susceptible hosts, early sowing of winter legumes (which gives crenate broomrape a longer…
- Cotton bollworm (Old World bollworm) on Cotton, Chickpea, Tomato, Maize · favoured by: Warm, dry weather; a landscape with a succession of flowering hosts (for example maize, sorghum and chickpea…
- Egyptian cotton leafworm on Cotton, Maize, Tomato, Potato · favoured by: Warm temperatures, continuous host crops such as Egyptian clover before cotton, irrigation, and heavy…
- Parthenium weed (congress grass) on Maize, Wheat, Cotton, Chickpea · favoured by: Disturbed or overgrazed land, bare soil after drought, roadsides and field margins, poor weed control in…
- Broad mite on Cotton, Orange, Potato, Tomato · favoured by: Warm, humid weather; shaded, dense canopies; continuous production of soft new growth; infested transplants or…
- Desert locust on Wheat, Maize, Barley, Date palm · favoured by: Unusually heavy or widespread rain in desert breeding areas (for example after cyclones over the Arabian…
- Verticillium wilt on Cotton, Olive, Potato, Tomato · favoured by: Repeated cropping with susceptible hosts, moderate temperatures, heavy irrigation and high nitrogen, root-knot…
Tropical and monsoon north
South Asia, mainland Southeast Asia and southern China, West Africa and the Sahel, Central America and the Caribbean · dry season
Sow and plant now
Growing: manage and protect
Nothing in the main calendar.
Harvest now
Get ready for June
Scout for
- Barnyard grass on Rice, Maize, Cotton · favoured by: Direct-seeded rice (especially dry-seeded) with no standing water early on, poor land levelling, shallow or no…
- Black cutworm on Maize, Cotton, Onion & shallot · favoured by: Weedy fields before planting, reduced or no tillage with crop residues, low-lying fields that flooded earlier…
- Fall armyworm on Maize, Rice, Cotton · favoured by: Warm weather with dry spells between rains favours outbreaks; heavy rain drowns young larvae in the whorl.…
- African armyworm on Maize, Rice · favoured by: The first heavy rains after a dry period, when fresh grass growth and moth concentration by storm winds…
- Aspergillus ear rot and aflatoxin (maize and groundnut) on Maize, Cotton · favoured by: Heat and drought during grain or pod filling, insect damage (ear borers, weevils, termites), late harvest…
- Beet armyworm on Cotton, Onion & shallot · favoured by: Hot, dry weather; weedy fields and field edges; large areas of host crops; and broad-spectrum sprays that…
- Charcoal rot (dry root rot) on Maize, Cotton · favoured by: Hot, dry weather and drought stress during flowering and grain or pod filling, sandy soils with low…
- Corn earworm (cotton bollworm, tomato fruitworm) on Maize, Cotton · favoured by: Warm weather, large areas of maize that build up populations before moths move to cotton, tomato and soybean…
Temperate south
Argentina, Uruguay and southern Brazil, south-eastern Australia, New Zealand, the South African highveld · autumn
Sow and plant now
Growing: manage and protect
Nothing in the main calendar.
Harvest now
Get ready for June
Scout for
- African armyworm on Maize, Wheat · favoured by: The first heavy rains after a dry period, when fresh grass growth and moth concentration by storm winds…
- Barnyard grass on Maize, Soybean · favoured by: Direct-seeded rice (especially dry-seeded) with no standing water early on, poor land levelling, shallow or no…
- Bird cherry-oat aphid on Wheat, Maize · favoured by: Early sowing of autumn cereals into warm soils, mild autumns and winters, a 'green bridge' of volunteer…
- Black cutworm on Maize, Soybean · favoured by: Weedy fields before planting, reduced or no tillage with crop residues, low-lying fields that flooded earlier…
- Charcoal rot (dry root rot) on Soybean, Maize · favoured by: Hot, dry weather and drought stress during flowering and grain or pod filling, sandy soils with low…
- Corn earworm (cotton bollworm, tomato fruitworm) on Maize, Soybean · favoured by: Warm weather, large areas of maize that build up populations before moths move to cotton, tomato and soybean…
- Cotton bollworm (Old World bollworm) on Maize, Soybean · favoured by: Warm, dry weather; a landscape with a succession of flowering hosts (for example maize, sorghum and chickpea…
- Fall armyworm on Maize, Wheat · favoured by: Warm weather with dry spells between rains favours outbreaks; heavy rain drowns young larvae in the whorl.…
Mediterranean south
South-western and southern Australia, the Western Cape, central Chile · autumn
Sow and plant now
Growing: manage and protect
Nothing in the main calendar.
Harvest now
Scout for
- Broomrapes of vegetables and legumes (branched, Egyptian and crenate broomrape) on Faba bean, Lentil, Rapeseed · favoured by: Repeated cropping of susceptible hosts, early sowing of winter legumes (which gives crenate broomrape a longer…
- Cowpea aphid (black legume aphid) on Lentil, Faba bean, Chickpea · favoured by: Warm, dry spells, drought-stressed crops, late planting, ant attendance, wild legume hosts and loss of natural…
- Bird cherry-oat aphid on Wheat, Barley · favoured by: Early sowing of autumn cereals into warm soils, mild autumns and winters, a 'green bridge' of volunteer…
- Dodder (field dodder and relatives) on Chickpea, Lentil · favoured by: Sowing crop seed contaminated with dodder seed, broadleaf crops grown repeatedly on infested land, broadleaf…
- Fusarium head blight (head scab) of wheat and barley on Wheat, Barley · favoured by: Rain or prolonged humidity at flowering, wheat or barley following maize or another cereal, residues left on…
- Parthenium weed (congress grass) on Wheat, Chickpea · favoured by: Disturbed or overgrazed land, bare soil after drought, roadsides and field margins, poor weed control in…
- Powdery mildew of wheat and barley on Wheat, Barley · favoured by: Dense crops, high nitrogen, mild humid weather, early sowing, volunteer cereals, and susceptible varieties.…
- Pulse beetles (bruchids) on Chickpea, Lentil · favoured by: Warm, humid storage; seed stored in open sacks or baskets; mixing new and old stocks; late harvest that allows…
Tropical south
Central and western Brazil, southern and south-eastern Africa, Madagascar, northern Australia, Java and the Lesser Sunda islands · dry season
Sow and plant now
Growing: manage and protect
Harvest now
Scout for
- Fall armyworm on Maize, Sorghum, Rice, Sugarcane, Cotton, Wheat · favoured by: Warm weather with dry spells between rains favours outbreaks; heavy rain drowns young larvae in the whorl.…
- Parthenium weed (congress grass) on Sorghum, Maize, Wheat, Cotton, Groundnut · favoured by: Disturbed or overgrazed land, bare soil after drought, roadsides and field margins, poor weed control in…
- African armyworm on Maize, Sorghum, Rice, Wheat · favoured by: The first heavy rains after a dry period, when fresh grass growth and moth concentration by storm winds…
- Barnyard grass on Rice, Maize, Cotton, Sugarcane · favoured by: Direct-seeded rice (especially dry-seeded) with no standing water early on, poor land levelling, shallow or no…
- Charcoal rot (dry root rot) on Sorghum, Maize, Groundnut, Cotton · favoured by: Hot, dry weather and drought stress during flowering and grain or pod filling, sandy soils with low…
- Maize weevil on Maize, Sorghum, Rice, Wheat · favoured by: Grain stored with more than about 13% moisture, warm stores, carry-over of infested grain or residues from the…
- Palmer amaranth on Cotton, Maize, Groundnut, Sorghum · favoured by: Reduced tillage that leaves seeds near the surface, wide crop rows that close late, reliance on a single…
- Spotted stem borer on Maize, Sorghum, Sugarcane, Rice · favoured by: Warm, dry lowlands; continuous or staggered cereal cropping; stalks and stubble left after harvest; low soil…