Slug fest among problems dumped on gardens by rain

With summer officially underway, a look back at spring 2024 could be summed up with one word — rain. Ozaukee County is having its seventh wettest year on record dating back 130 years. For farmers, it’s been a huge challenge, wreaking havoc with harvesting and planting crops.

The impact on gardeners, however, is significantly less. In fact many gardeners are likely seeing rather amazing growth on plants thanks to the plenitude of rain.

While all this water means that gardeners are spending very little time lugging around hoses to water everything from new plantings to containers, we’re starting to see some negative impacts of the wet spring.

In my garden, I’m noticing signs of chlorosis much earlier than I normally do. In our high pH soils, chlorosis, typically identified by yellowing leaves with green veins, is often related to a plant’s inability to absorb iron more than it is a lack of iron in the soil. But excessive rain can wash minerals out of soil faster, so in this case it’s probably a combination of that and high pH.

The affected plants, which include panicle hydrangeas — Limelight seems particularly sensitive — and a compact Virginia sweetspire (Itea virginica) called Fizzy Mizzy, are quite happy with moist soil but prefer a soil pH that is slightly more acidic than is typically found here.

The treatment is two-fold. Supplemental iron will remedy chlorosis quickly, but it’s likely to return. Soil acidifier, which does not work quickly, might help a few months down the road, although it’s not a truly long-term fix. (Soil pH is not something that can be permanently changed.)

There’s a good chance that some plants may also need fertilizer as nutrients are washed from soil. There’s no need to go crazy and fertilize the entire garden, but hungry plants — roses, Clematis, Phlox and daylilies, to name a few — may be in need of some.

The same holds true for container plantings with flowering annuals. I plant all containers with a time-release fertilizer, but regular applications of a water soluble fertilizer will keep blooms coming. And while it may seem contradictory to add more water with a water soluble fertilizer to already wet containers, the odds they need the nutrients.

And lastly, you’ve probably noticed a lot of slug damage in the garden. It’s a slug paradise out there this year and they are having a field day. If the damage is bothersome, a slug bait made from iron phosphate can help and is safe for people and pets when applied according to the label.

Of course there are other slug deterrent methods, including various mulches around plants that slugs find irritating, garlic sprays that will make you crave garlic bread even if the effectiveness at deterring slugs is questionable and beer traps.

Or, if you are a gardener who seeks adventure, you can go out at night with a headlamp and hand-pick slugs off your prized plants. But you might want to wear a raincoat. More rain is in the forecast.