Problem type: Environmental
Name of problem: Hail Damage
Plant name(s): All plants
Symptoms / Characteristics:
Plant leaves may be bruised, torn and tattered looking and many may be knocked off the plant and scattered on the ground. Twigs, branches and trunks can have puncture holes, gauges or tears ranging in severity, and limbs may be completely broken or dangling. Herbaceous plants may be laying down with tattered leaves, stems and flower stalks. Broad-leaved plants such as hostas may be more severely damaged. Fruits may have pit holes, bruising or can be knocked to the ground.
Control / Preventions:
Successful plant recovery depends on the type of plant damaged, plant maturity and what time in the season this occurred. Carefully assessing the damage should be the first step, noting what type of plants are damaged and which ones will survive, making note as to how long they have left in the season to recover before winter.
Trees and shrubs are more costly then perennial or annual plants, so they should be a first priority. All broken, hanging or severely damaged limbs that will not heal quickly should be cut off cleanly. Minor wounds can be left to heal naturally but can be protected by a fungicide application to prevent diseases from entering the wounds. Damaged fruits should be removed, as they will only attract pests.
Annuals can normally survive hail damage readily if damaged plants are trimmed back and a light application of fertilizer is applied to help them recover. Perennials can be trimmed up as well but sparingly, as they need good top and root growth for winter hardiness. A light fertilizer application and close monitoring for insects the next few weeks should be done to aid in plant recovery and future health. Hail damage in the spring does not affect plants as badly as damage occurring in mid to late summer. The later in the season, the less time the plant has to prepare itself for winter, and if that time is not there, they might not survive. Plants not showing signs of recovery within a week should be replaced with new plants.
Vegetable crops can usually recover from hail injury. Trim off damaged leaves on leafy crops but leaves removed on root crops should be kept to a minimal. Early season damage to root crops with badly damage tops will produce little yield. Late in the season, root crops may be mature enough to survive and produce a good crop. Replace any plants in the garden if there is no sign of recovery within a week.
Putting mulch down around damaged plants can improve their survival over the winter. Protecting more fragile plants by planting in protected sites or providing temporary covers before a storm if possible can reduce damage. Keep in mind that poor plant health, or plants not surviving the winter may be due to a hailstorm that occurred months before and has been forgotten. Plants can show effects of damage, months or years after an injury, so recognizing that recent occurrences are not always the cause of a problem is important in determining the cause.