Wild summer storms can discourage home gardeners as well as farmers. The best defense is a good offense by using proper cultural practices – location, watering, fertilizing and pruning techniques – from the beginning of the season. When hail happens, trees, shrubs, perennials, and annuals can successfully survive if the proper maintenance is done after damage.
Trees and Shrubs
Prune off any broken branches caused by hail. Use proper pruning cuts, taking care not to cut into the branch bark ridge. If trees or shrubs were split and large limbs were broken, clean the wounds with a sharp knife or pruning shears. Browned leaves will not turn green. To assess the ex-tent of damage, move up the plant and past the leaves to check how far back dead material extends. Dead twigs will snap. Moving further back on the branch, you can use a knife to scrape the top of the branch to look for live wood. Prune twigs and branches at the point where there is live, green wood. Do not apply paint or wound dressings, but let the wound close naturally. If damage is too great, consider removing the plant.
Continue to inspect branch wounds closely and monitor throughout the growing season. Many wounds will callous over with proper plant watering and maintenance. Be vigilant about spotting Fire Blight if humidity and temperatures (60°F to 85°F and relative humidity above 60%) are conducive to the bacterial growth. A preventative spray of horticultural oil in the spring or fall can reduce overwintering egg casings and spores.
Hail often destroys leaves, but trees may have enough reserves to re-leaf. Because this takes a lot of energy, be sure to give the tree adequate water throughout the summer (approximately one inch per week, depending on species). Applying two to three inches of mulch at the base of the trees but not touching the trunk and shrubs will also help moderate soil temperatures and maintain soil moisture.
Annual flowers and edibles
Plants that are completely stripped of foliage and have broken stems should be replaced. If less than one-third of the plant remains, it is probably not worth trying to save. Other plants with less damage might be salvaged, but they will need time and care to recover.
- Trim and remove severely damaged leaves so that the energy of the plant is directed to create new growth. After trimming, spray edibles with a copper-based product available at garden centers.
- Apply fertilizer to promote growth. Pat Appleby of Canyon Creek Nursery suggests Soil Diva either to spray on foliage or as a soil drench. It will enhance microbial activity to stimulate the plants.
- Water regularly without stressing plants with too much or too little water.
- Place new plants between damaged ones to provide instant color in the case of annuals – and to help insure a harvest in the case of edibles.
After a very intense storm, the soil around plants tends to form a crust after it starts to dry out. Use a small hand rake to gently work around those plants and break up that crust so it doesn’t form a hard shell.
Perennials often have secondary buds that will provide new growth following hail damage. Perennials also require optimal care following hail so that they not only survive the current season but gain the health to overwinter and bloom again next season. Trim perennials back as far as the extent of the damage is visible. This also applies to perennial grasses.
Apply fertilizer to provide nutrients that will generate growth.
Do not cut back damaged foliage on bulb flowers such as daffodils and allium. The leaves enable photosynthesis which feeds the bulbs though severe damage may cause less vigorous plants the following year.
Water adequately. Xeric plants may need more water than usual to help them recover more quickly.
Living with Hail
In areas more prone to hail, use a cloth designed to protect plants from hail (or sun). Pat suggests using a 30% block to allow moisture and light to reach plants while protecting them from hail. You can also look for finer-leafed plants such as cosmos which the hail often falls through rather than shreds.
Associated Landscape Contractors of Colorado https://www.alcc.com/dealing-with-weather-damaged-plants.
Ask an expert Cooperative Extension https://ask.extension.org/questions/395347.
Colorado public news http://www.cpr.org/news/story/after-hail-advice-resurrecting-your-garden.
Interview with Pat Appleby of Canyon Creek Nursery.
~Submitted by Elizabeth Waddington