Assessing Tree Damage from the Derecho

Iowa residents are still feeling the impact of the Derecho that blew across the state on Aug. 10, 2020. While the loss to landscapes shouldn’t be overlooked or ignored, it is important to take a breather, wait and make a plan for spring.

It can be shocking to lose trees, especially large ones. Taking a breather and reassessing the landscape during the fall is OK, and fits in with herbaceous plants senescing, and woodies going dormant, as is natural this time of year.

If you are itching to plant this fall, avoid conifers due to winter desiccation issues. If you do choose to fall plant conifers, focus on heavily watering them each week leading up to frost, and again, if we get intermediate warm spells before winter really sets in. The extra soil moisture is needed since they bear foliage/needles all winter long and lose moisture.

It is important to remember that trees still available at big box retailers are leftovers from summer. These have likely seen stress and might not be ideal for your landscape. This is truer with large retailers than garden center or nurseries. You can purchase groups of deciduous trees from the Iowa DNR Nursery for $1 per tree this fall.

As you assess your landscape this fall into the winter, make sure to note the sun patterns in your landscape, and take note of what understory plants that may be affected. Once shaded plants might not receive the same amount of shade now, even when planting a replacement.

You should consider moving shade-loving plants around the garden. While shade-lovers may be getting crispy this fall in full sun and they might shutdown early, the root systems should still be in good shape. Water as needed to maintain soil moisture and to keep the root systems healthy. Most perennials can be moved in spring but do this before leaves emerge or just as they are starting to come up (i.e. when you can first see the hostas come up but before they are in full leaf).

A new garden plan will need to be created to deal with larger plants that can’t be easily moved.

Planting considerations

• What to plant is a major consideration, and requires homework—which can be done over the winter, don’t rush it. Consider native trees, and check with local urban foresters and county conservation boards.
• Consider why the original tree failed, and think about planting a different tree.
• Consider diversifying your landscape. Plant something different from your neighbor’s yard, help create a diverse landscape on the scale of your neighborhood.
• Consider where the trees should be, not where they were. Place trees away from the house or other structures, and when near them, place where structures can benefit from energy efficiency.
• Consider where the shade will be. Shade is not directly below the plant because most of the sun’s rays come in at an angle. This angle also changes during the year and interacts with tree height as well. Understory shad plantings might need to be reevaluated, as they are unlikely to get shade immediately.

Fast growing trees might offer shade sooner, but plant those with caution. While fast-growing trees are not necessarily weaker by nature, their fast growth usually leads to double leaders, which is associated with included bark. While fast-growing trees can have a fruitful life, they also need to be pruned early and often.

Dealing with major landscape disruption can be a daunting task, that is why it is important to take your time, assess the situation and make a plan that will be successful.