When, Who, How, & How Much to Water
Midday, on a hot day, watering will burn the leaves.
Evening watering promotes mildew, fungus growth. Plants drink during the day, so AM watering is best.
Plants that need little or no water and why:
Onions, garlic, that are flowering, going to bulb, needing to dry
End of season tomatoes that you want to have a stronger flavor
Tomatoes in soil with Fusarium and Verticillium Wilt fungi in the soil. Fungi don’t do well in dry soil.
Plants that need water almost daily, sometimes twice daily
Shallow rooted beans, beets, bunch onions, cucumbers, peas, strawberries
Celery and chard, lettuce, arugula – leaf crops, to keep them growing fast, tender and tasting sweet.
Planted seeds, seedlings, newly planted transplants, must be kept moist; if they dry, they die. Put up temporary shade.
Use a watering can for seeds and tender seedlings so seeds aren’t washed away or seedlings broken.
Most plants need only an inch of water once a week unless it is hot and/or windy weather. Most gardeners over water by two times as much as is needed! Overwatering drowns plants, and kills micro soil organisms; they don’t get oxygen. Soil structure is destroyed as air spaces cave in. Overwatering also causes poor root growth making it difficult to move enough water to the leaves during hot weather.
Irregular watering results in misshapen fruits, tomato flower drop, can stop production
Fuzzy plants like tomatoes, eggplant, don’t do well with watering on their leaves. Water underneath please.
Plants that are mulched generally need less water. Poke your finger in the soil to see how deeply it is moist. More on mulching next week.
Water and Pests & Diseases
Overhead watering contributes to mildew on beans, squash, peas. It spreads Strawberry Leaf Spot and other waterborne diseases
Tomatoes: stop watering when about a foot tall. Water around them, but not right at them. Keep back about a 2’ perimeter to reduce Fusarium and Verticillium Wilt fungi. If you do water them, on mature plants, cut off the lower leaves, up to 18” high, to prevent soil splash when watering. The fungi are especially taken up by leaves touching the ground.
Flush off aphids and the undersides of broccoli leaves and broc side shoots, kale leaves, especially the curly varieties.
Flush white flies from the undersides of broccoli leaves, kale, beans