Unfortunately, hail damage is not easily prevented. Traditional best management practices such as mulching, watering to keep soil moist, and incorporating compost to improve soil tilth don’t reduce the likelihood or severity of damage. In general, less damage occurs on conical or upright growing plants, however, it’s not feasible to fill the landscape exclusively with specimens of this architectural type. As well, this type of branch arrangement often leads to tight branch angles and future limb breakage in subsequent storms.
Hail causes damage in all landscape plants – grassy, woody and vegetative; occasionally, even lawns are damaged when hailstones strike the crowns, although most have a thatch layer that buffers the roots from injury and blocks extreme soil compaction.
In trees and shrubs, injury occurs by creating wounds that often lead to heartwood decay and interrupting nutrient/water flow in the conductive vessels. In the long run, the hail strikes gradually weaken the sapwood and heartwood of woody plants often resulting in structural instability.
In veggies and small fruits, plants are damaged through shredding of the leaves and stems. As with woody plants, the conductive vessels are also often rendered non-functional.
In perennial flowers, damage commonly occurs on the leaves and flowers, which is disfiguring, but the main concern is the crown of the plants, the tissue where all future growth will be produced.
Hail Damage Recovery
Each group of plants in the landscape should be treated differently in terms of responding to hail damage.
In the vegetable garden, strawberry/raspberry patch and asparagus bed, it’s best to remove damaged plants and plant parts. If a major stem or portion of the plant is mostly intact, it’s worth the effort to cut away and remove the damaged part(s) and allow the remaining sections to recover. In areas of the garden where large plants have been removed, consider replanting with short-season cultivars of the same or different crops. Depending on when the hailstorm occurs, it may be possible to shift a summer planting to a fall garden.
- For ornamental trees and shrubs, it’s important to assess damage, especially to the permanent parts of the plant. Inspecting shrubs and small trees for hail strikes is relatively easy for shrubs, but any tree that can’t be reached from the ground will require assistance from a qualified arborist, preferably one that is certified by the Nebraska Arborists Association (NAA) or the International Society of Arboriculture (ISA). These professionals have the knowledge, experience and equipment necessary to conduct a thorough assessment and remove limbs that are sufficiently damaged to be a future concern for the tree. Using lopping pruners and a small pruning saw, entire stems/canes should be removed from shrubs at the ground level. The damaged branches of small trees within reach can be removed using the 3-cut method. Allowing lightly damaged stems and branches to remain will provide the opportunity for these wounds to close and the plants to return to normal function.
- For fruit trees, removing badly damaged branches will serve the plant similarly to ornamental trees, however, since many fruit growers are reluctant to prune adequately, fruit trees often need thinning as well as damage mitigation. At this time, take the opportunity to remove crossing and closely parallel branches to allow adequate light and air to flow through the tree canopy. If the hailstorm occurs after mid-June, it’s best to wait until late winter to remove non-damaged branches.
- For all woody plants, keep “pruning dose” in mind. Ideally, no more than 20-30 % of the stem/branch tissues should be removed with any one pruning event. The best approach is to remove the most badly impacted branches and then reassess the subsequent growth response and overall health of the tree/shrub. A second light pruning can be done in the future if needed.
In general, after storm damage occurs:
- Keep the soil moist but not soggy.
- Avoid fertilization until the plant recovers and produces new healthy growth
- Mulch between plants to prevent weed competition
- Make notes about hail event dates in a garden journal and take pictures of damage to various plants in the landscapes. These references are valuable when attempting to diagnose problems in future years that may be related to hail injury.
- Re-inspect plants one month after hail events to determine if any unforeseen damage develops over time.
For more, check out videos from Backyard Farmer:
Hail Damage Tips: https://youtu.be/vIeA731LQg8?si=SK1XnbzWnd2YUvaL
Hail Damage Recovery: https://youtu.be/K4OxrLskm2g?si=On0kOM9sPilH65fB