Monday, April 25, 2016

Spring Rains Bring Out The Green- Spring Lawn Care

Wiese Acres Plum Blossoms
After an unusually mild winter, with temperatures sometimes 40 or more degrees above normal, and little or no precipitation, early Spring has not given us our usual lush green hillsides. Last week, we finally got some precipitation and oh, what a difference it's made. Today, the grass is the brilliant emerald green that only Spring can bring. The tree leaves are bursting open and the earlier fruit trees have exploded into full bloom. Yesterday, it started raining at around 10:00 AM.  It rained off and on all day, and is still raining this morning. During the last lull, I ventured out to the rain gauge and found we'd had about 2.25 inches of rain. What a spirit lifter!

It does mean, though, that it will be time to do something with the lawn grass soon. Yes, I know a lot of people have already gotten their mowers out and given their lawn its first (or maybe even second) haircut of the season. I know there are a lot of really ambitious folks who have already applied their Spring dose of weed and feed. Here? Not yet. There are a couple reasons for that.

One is that I simply am not so in love with grass maintenance that I want to start it any earlier than I absolutely must. But, secondly, and more importantly, there is such a thing as jump-starting your grass too early in the season.

In North Dakota, and most other places where Spring arrives in late March or so, you can generally begin mowing your lawn in mid to late April without many problems. The downside of getting at it too early is that once the grass is cut short, it opens more of the ground to the sun, giving all those weed seeds lurking under the grass blades the exposure to sun they need to germinate. A cold snap will keep the grass from growing, but doesn't seem to faze the weeds. Since it isn't advisable to put weed killer or fertilizer down on your grass until at least mid-May here in zone 4, that might just mean that you spend more of your Spring fighting weeds than you do enjoying your nice lush lawn.

Mowing too early also has the potential to damage the vulnerable new growth. Grass that has been given the opportunity to "toughen up" a bit will tolerate the insult of the lawn mower much better. Those cut ends are even more vulnerable than the rest of the grass blade, so a cold snap can do damage to the grass itself.

Regardless of when you mow, it is important that your mower blades be good and sharp and that the blade is level on the mower. Sharp blades cut the grass cleanly rather than fraying the ends, and this allows the grass to "heal" more quickly. Uneven blades leave, well, uneven lawns.

There are two schools of thought on how short is short enough for the first mowing. There are the "scalpers", those who mow it as short as possible to get all the dead grass cleaned up. This technique does tend to give you a more immediate beautiful rush of new, green growth. Those who don't like this method feel that the short term gain isn't worth the long term work it creates. Remember that thing about exposing the weed seeds to the sun they need to germinate? Rest assured, the weed seeds clap and cheer when they see that mower blade coming right down on top of them.

The other school of thought is that you should not take more than the top 1/3 of the grass blade with any mowing. This causes less trauma to the grass and leaves some cover on the ground to keep weeds in check. After the first couple mowings with this method, you will have accomplished the same results as that first scalping, but without quite so much risk of weed germination.

Fertilizer should not be applied until the grass is in its active growth cycle. Here, the recommended time for Spring fertilizer application is the middle to the end of May. Conventional wisdom says this should be a Memorial Day weekend activity. Most grasses don't begin active growth until daytime air temperatures are consistently in the 60s and nighttime temperatures are in the 50s. That generally equates to soil temperatures around 60 degrees, which is what is necessary for consistent grass growth. Fertilizing too early does nothing for your grass, even if it makes you feel better.

Lawn should be dethatched if the thatch layer is more than 1/2 to 3/4 inch thick. Thatch is the dead grass and roots that build up at the soil level. If you dig up a small plug of soil several inches deep and look at it horizontally, the spongy brownish layer next to the soil surface is the thatch.  If you compress it and it remains 1/2 to 3/4 inch thick, it is time to dethatch. Ideally, you should have mowed your lawn two to three times before you think about dethatching.

Power raking is one method of dethatching. A mechanized rake is run over the entire lawn, tearing up the thatch as it goes. Unfortunately, it can also tear up the good grass. It does less damage if you cut the grass very short (about one inch tall) before running the rake over it. You may need to "baby" your grass with extra water and vigilant weed control for a time after power raking.

Core aeration is another method that not only helps thatch decompose, it also helps loosen compacted soil. Core aeration perforates the soil with many small holes, pulling up a plug of dirt out of the hole. This allows air, nutrients, and water to reach the grass roots better and hastens the composting process of the thatch. This works best for less severe thatch problems. A very deep thatch may require both raking and aerating.

If you choose to dethatch or aerate, these should both be done prior to putting on a weed control product. Both processes bring weed seeds to the surface where they can germinate, and by putting the pre-emergent herbicide on after, you can eliminate many of your weed problems.

Yes, lawn grass is a lot of work. I much prefer my perennials - I'll work hard on them for a couple  months and then sit back and enjoy. Grass, on the other hand, is very needy and demands attention at least once per week all summer long.

But, for now, it's still raining, so I can just sit back and think about taking care of that grass. It isn't good to work on your lawn when the soil is too wet. Thank you, Mother Nature, for the moisture and the reprieve.

Wiese Acres Flowering Crabapple