New POP resource on orchard irrigation!
Phil Forsyth
Orchard Irrigation
In Philadelphia’s generally humid, wet climate, we have long advised that you don’t need to water mature orchard trees unless there is drought. But extreme weather conditions have become our norm. Rainfall has become less predictable, heat more intense, and drought more of the rule than the exception. Plan on needing to irrigate your orchard at some point during the year and be prepared for longer periods of drought.
Checking Soil Moisture
Tree crops can suffer with no significant rain for 3 or more weeks. Check ground water levels and
Check soil moisture by digging to the depth of roots and feeling the soil. Fruit tree roots are mostly 8-14”. Water when soil moisture is at 50-60%.
For loam → Clay soils
0-25% Crumbly, powdery, cracked. No ribboning. No to slight stain on fingers.
25-50% May form ball or ribbon, but crumbly/falls apart. No to slight stain on hand
50-75% Soil color darker. Forms ball and ribbons easily. Stain hand.
75 -100% Soil color is dark. Appears and feels moist. May be sticky. Forms ball and ribbons easily. Slick feel when squeezed. Stains hands.
Irrigation Systems
Hand Watering (hose or bucket)
Water entire root zone, from trunk to drip line, and then some. Watering beyond drip line encourages root growth.
5 gallon buckets with a few 16” holes drilled into bottom or very low on sides. Place around drip line. Fill with water. Once emptied, move and repeat.
Turn hose down low and leave on for 1-2 hours. Move every 20 minutes until entire area underneath canopy is soaked.
Overhead Watering (oscillating sprinkler)
Move around every 1-2 hours to get full coverage of plantings
Try to minimize canopy getting wet, potentially spreads fungal diseases.
Avoid watering when windy.
Orchard Watering Schedule
*Potted plants and raised beds will require more frequent watering: the smaller the container or higher the bed, the more often it will need watering
How much water
On average plants need 1” water per week in our climate
Track rain accumulation and irrigate to make up difference, if needed
Shallow roots require more frequent watering, deep roots less frequent.
Sandier soils require more frequent watering, clay soils need less
Hotter, sunnier and windier weather increases amount of water needed
Different species also have different resilience to drought, with figs needing significantly less supplemental water than pome fruits.
