Calls to the Master Gardeners on lawns have included questions on weeds, mushrooms in the lawn, lawns going off color and mowing properly with all the rain. Existing weeds and any weed seeds that have germinated are taking advantage of any open or thinned areas in the lawn to get a good start for the growing season.
Mushrooms in the lawn come from decaying organic matter that is naturally there. Mushrooms can appear in the thatch layer or from decaying roots in the soil. The high levels of soil moisture right now are really promoting all kinds of decay organisms and soil microflora.
Lawns right now are losing that dark green color and fading to a light green. This is likely a response to all the water and the dilution of nitrogen in the soil profile. High organic matter soils show less of this change. Cooler soil temperatures also influence nutrition uptake by all plants, adding another factor to the mix and why plants besides the lawn may be showing similar signs.
Mowing the lawn when it needs to be mowed has been a real problem. The better practices of mowing when the lawn is dry and not too tall has not been possible. Tall grass has a tendency to stay wetter longer and makes the situation worse. Right now setting the lawn more blades to cut the grass taller is helpful and slowly lower the blades back to your normal settings will keep the lawn from going into shock from being mowed too short all at once. Collecting clippings may also be advisable if the clippings are clumping on the top of the lawn. The clippings can be added to the compost pile and turned in with the contents so there is no odor.
Landscape and garden diseases have been higher than normal because of all the rain. Calls to the Extension office have been running high for tomato foliage problems and Cedar Apple Rust and Apple Scab on flowering crabapples and apple trees. Most of our tomato leaf diseases are overwintering right in the soil and just wait to be splashed up with the soil t the lower interior leaves of the tomato plant. The longer the leaves remain wet or there is high humidity, the more spores can infect the leaves. Besides Septoria and Early blight leaf fungus, we are seeing more bacterial blight as well. If the weather continues to be wet, then we can expect to see fruit rots on the vine crops that sit directly on the soil. Mulching the soil to keep the splashing down will help to keep foliar diseases down and protect the vine crops from belly rot.