Drought stress is an abiotic disorder that causes wilt, growth reduction, early onset of fall colors, and premature leaf drop in trees and shrubs. It occurs when the amount of moisture in the soil no longer meets the needs of the plant. Drought stress can be caused by lack of rainfall, inadequate irrigation, windy conditions, high temperatures, low humidity or other factors that cause transpiration rates. When conditions are not managed, it can increase the tree’s susceptibility to insect and disease pressure.
- Wilting and marginal necrosis of leaves are common symptoms of drought stress in trees and shrubs.
- Long term water deficit can cause slow growth rate, reduce leaf size, early fall colors, leaf drop, and branch dieback
- Note that these symptoms can be caused by other abiotic or biotic stressors such as over watering (aeration deficit), compaction, root diseases, insects, etc. It is best to keep track of environmental conditions to properly diagnose the problem. Below are some examples:
- Are other plants nearby have the same symptoms?
- Check the soil, is it dry or compacted?
- Check evaporative demand, is it hot or windy?
Soil applications of Hydretain or NutriRoot.
Hydretain is a blend of hygroscopic and humectant compounds that attracts water molecules within the root zone and allows the plant to absorb soil moisture that would have been lost due to evaporation. Hydretain can be applied through drench, soil injection, fertigation, or topical soil spray followed by irrigation. Apply 4 to 8 fl. oz. of concentrate (dilution rate of 2 fl. oz. per gallon of water) for each inch of trunk diameter and drench thoroughly in the root zone. Hydretain is also available in a granular form for broadcast applications or incorporation into the soil at planting.
NutriRoot is an unique blend of nutrients, seaweed extract, humic acid, surfactants, and Hydretain designed to increase root development and reduce water stress. Apply through drench, soil injection or topical soil spray.
Drought events and season dry periods vary from region to region. For best results, Hydretain or NutriRoot should be applied prior to or at the beginning of the onset of dry conditions or as temperatures begin to rise during the summer season; however, the products may be also be applied after drought stress is observed. Reapply Hydretain every 3 months or as needed. Apply NutriRoot once a month throughout the growing season. For northern areas, apply Hydretain or NutriRoot in the fall to alleviate plant stress during the winter cold, should be done before the ground temperatures drop to 40ºF.
If application occurs prior to the onset of drought stress, trees and shrubs will maintain vitality as neighboring trees and shrubs begin to wilt, burn or experience thin development. The rate of recovery for drought-stress trees and shrubs will depend on the severity. Overall, you should see reduced signs of drought stress including reduced wilt, better canopy color and fullness, and discontinued necrosis. When using NutriRoot, you can expect to see an increase in root development along with improvements of canopy quality from the added nutrients.