This week, Johnson County saw its first decent bout of rain in seven weeks.
This was good news for plants and trees after Johnson County (and most of the rest of Kansas) moved into what the National Integrated Drought Information System, or NIDIS, calls severe drought conditions — especially in the northeast part of the county.
- But while the rain helped, it might not be enough to fully rejuvenate the plants that have suffered from it.
Here’s how the drought has impacted local plants, trees and yards — and what that might look like if the dry conditions continue through the fall and into winter.
What we know: Dennis Patton, horticulture agent at the Johnson County K-State Research and Extension Office, says trees, shrubs and turf are being impacted the most severely.
- Some of the signs of a plant suffering from drought include rolled and yellowing leaves or wilting.
- Evergreen trees in particular are susceptible to drought conditions, and while those aren’t pervasive in Johnson County, Patton said a lot of Emerald Arborvitae plants (an evergreen plant commonly used for outer yard screening and decoration) died this summer.
- Droughts can happen in either high or low temperatures, but Patton said it causes plants the most stress when it happens during warmer periods — partly because the summer is when plants go through a lot of their growth processes.
Key quote: “Lack of moisture still has the same effect on plants,” he said. “But heat stress on top of drought just adds another stress factor. Obviously, the more stresses you put on something, the more likely it is to collapse or fail.”
What else: Johnson Countians who have used park trails recently might have also noticed another phenomenon: uneven trail surfaces.
- Patton said this can happen to clay soils during drought periods because clay shrinks when it’s dry.
- This means that when soils with heavy clay content dry out, the clay can shrink and produce cracks that weren’t there before.
- When houses are built on top of these kinds of soils, this shift in soil can also cause houses to “settle” more often, leading to cracks in plaster and dry wall inside a home.
What about the rain? The rain Johnson County got earlier this week is a start, Patton said, but it won’t be enough by itself to end the drought.
- Rainfall is most effective for plant growth when it happens in smaller spurts every two or three weeks, versus happening in a larger spurt every six or seven weeks.
- This is because plants can only store so much water in their soil, and once it runs out, they need a new source.
- Patton said this type of infrequent rainfall is a climate pattern the greater Kansas City area will see more often in the coming years, which might shift the way plants and trees need to be cared for in the area.
- “That’s one of the potential problems we’re seeing, more uneven distribution of rainfall,” Patton said. “If it doesn’t rain again for six months or six weeks, there’s nothing to support that plant down the road.”
What it means for winter in Johnson County
Without more rainfall in the next six or seven weeks, Patton said plants and trees might not have sufficient preparation for colder temperatures and harsh freezes.
- This is because plants with sufficient soil moisture are better protected against cold winter temperatures — especially Evergreen trees and shrubs, which are particularly at risk since they aren’t native to the area.
- Watering plants and yards helps in the meantime, Patton said, but they need more widespread forms of precipitation too in order to get all the water they need.
- “We’re not out of drought conditions yet, but (this week’s rain) is a step in the right direction,” he said.
