Farmers Weekly Review

There are some garden topics that I feel a need to repeat every year. Because no matter how many times I go over them or talk about the science behind them, some people will still do them.

The top one is confusing yellow jacket wasps for any “bee.” But that one is a mid-summer reminder when the populations of yellow jackets get as busy as the local pool on a 100-degree day.

The early spring reminder is always the same — do not till or work your soil when it is wet. Or I will have to call you what you have just made … a clod! Even seasoned gardeners sometimes get the overwhelming urge to literally dig in while the early spring soils are still saturated.

Whether it is digging with a shovel, or a worse case scenario, using a tiller, working wet soils can create a long-term disaster for the garden. Tilling wet soil squeezes all of the open space between soil particles and creates nearly impenetrable large clods that can take the whole season to break down.

I know it is tough to wait, especially in a wet spring, but it is worth it. That is why I always advocate fall soil prep, even if it is just a small area for your early spring vegetables: salad greens, spinach, peas and onions. These vegetables can tolerate quite low temperatures down to the mid-20s.

And speaking of temperature, don’t let the sales at the garden center dictate your time of application for various controls. Crabgrass and grub control products are the two that get misapplied all the time. Follow the science, not the 3-foot-tall cardboard grub cut-out, hanging in the garden section.

First a little botany lesson. Grassy weeds, from a casual glance, look the same—wide-bladed, different habit than the desirable turfgrasses we grow. But the treatment is vastly different for the different species. Already commercials and sale papers are touting crabgrass preventative applications.

Crabgrass is an annual grass. That means that every year it grows from seed that is in the soil from last year’s crabgrass weeds. Each year, crabgrass makes its inflorescence (that make the wheat looking, purple bronze seedheads that appear in August that you probably don’t notice).

But it is important to understand that crabgrass starts from seed each year, because  crabgrass preventer works by putting down a chemical “blanket” that prevents the crabgrass seeds from germinating.

This is the opposite rationale from using weed-and-feed products. When you go to apply dandelion killer, we need to have those weeds up and growing, because that chemical works through the leaves of the plants.

But like the old saying says, “timing is everything.” Many people apply crabgrass preventer as soon as it is on sale at the garden center or big box store. Big mistake. If you apply crabgrass preventer when the soil temperature is too low, it will dissipate before the crabgrass is ready to germinate, so treatment can be partially or completely ineffective.

Crabgrass preventer should only be applied after our soil (not air) temperature reaches 10 consecutive days of 55 degrees. You can find the Northern Illinois soil temperature (that is, if you don’t have a stem thermometer that you can check your own soil yourself) at https://www.greencastonline.com/tools/soil-temperature I just checked now and currently our soil temperature is 33 degrees.

So, we are far from those 55 degrees for 10 consecutive days. And the consecutive is important, too. If it is 55 degrees or above for a few days, then drops below, the count starts over again. Remember, you only apply crabgrass preventer once each year; make that timing count.

Besides wrong time of application, another issue is misidentification of which grassy weed is which.

If you look out to your turf right now and see greening clumps of wide-bladed grass, many of my callers will tell me they waited too long to get the crabgrass preventer on and ask what they need to do now. But no — any existing grass you see that doesn’t look like desirable turf is a perennial grassy weed. Most likely you have quackgrass.

Quackgrass is a perennial weed. So, think of crabgrass like a marigold, plant every year; quackgrass is like a coneflower or evergreen, comes back from roots every year. Quackgrass is our most challenging grassy weed. It can soon take over your lawn in large unruly patches with underground runners, if you don’t address it early.

And the reason it is overlooked is homeowners think that their crabgrass preventer will take care of it. It won’t. If you have any grassy weed that is in your lawn right now, it is definitely a perennial grassy weed. And the treatment is completely different.

To become your own turfgrass botany expert, pick one “grass plant” — this includes the root, fibrous stem and blade. Look where the blade connects to the stem. Think of this area as a collar on a shirt, also botanically known as an auricle. This is the main identifying area for grasses.

If your collar clasps around the stem, like a button-down shirt, it is quackgrass. Crabgrass is a T-shirt — no collar. Or you can send or bring me a sample to look at to identify any plant, insect, disease, etc., for you.

The other early spring question I get calls on, is how early is too early to plant? For this, we look to the classification of cool vs warm season plants. The cool season plants like violas, alyssum, pansies, stocks, snapdragons and salad greens, spinach, peas, and onions can tolerate cooler temperatures. The latter vegetables can tolerate even as low as mid-20s.

But you know our Mother Nature’s habit of treating the outdoor thermostat like a roulette wheel. What happens if the temperatures suddenly drop to 12 one night? Keeping some type of insulator protection nearby to cover early planted flowers or vegetables will prevent a severe low temperature from freezing them.

You can use a cotton sheet, newspapers, or if you want to get fancy, a cloche or floating row cover. Just never a sheet of plastic.

If you put plastic on, it protects overnight, but if the sun comes up on it, it creates a greenhouse effect and without ventilation, will fry your plants.