Down the Garden Path: FAQs for early spring

Calls and emails to the office and Master Gardener Help Desk this time of year are often a mix of “When can I…?” or “Is it too late to…?” questions. Here are a few common examples:

Q: When should I be putting down crabgrass preventer?

A: Crabgrass along with other annual grasses will want to have soil temperatures greater than 55 to 60 degrees Fahrenheit (°F) for seven to 10 consecutive days and continues until soils reach 95°F. Other annual grasses germinate as soils get warmer than 60°F. That is likely to be 3 to 4 weeks away, depending on how Mother Nature behaves. Ideally, getting the product on the lawn just before that will give the longest time of protection. Too early and crabgrass can still show up. Putting the preventer down too late, you get the early crabgrass surviving while the later germination is prevented. As with any product, always read and follow label instructions.

Q: What other efforts should I consider for my lawn?

A: There can be many fungal diseases happening in the lawn over the season. With the exception of “snow mold,” environmental conditions are not right for most yet. If there has been a history of lawn disease, prepare to apply an appropriate fungicide starting about 10 to 14 days ahead of when you have observed the disease in the lawn previously.

If fertilizer is on your to-do list, hold that thought. It is too early to do a spring fertilizer application. Let the natural flush happen first. Plan to mow 3 to 4 times or wait 3 to 4 weeks before applying fertilizer. Last but not least, when the growing season hits, remember the mantra, “Mow high, mow often, and mow with a sharp blade.”

Beyond the lawn itself, we can start caring for that lawn mower. Change the oil if appropriate (raise your hand if you did not change the oil last fall), clean the inside of the mower deck, replace or clean the air filter, and replace the spark plug if it has been awhile (the mower will start much easier). More important than you can imagine is sharpening the mower blade. A sharp blade will leave the lawn looking better, create less entry wounds for disease, mulch up the cut grass better so it filters back into the lawn, and put less strain on the engine while reducing carbon emissions. Who would have thought that one action had so many benefits?

Q: I still need to do my dormant shrub pruning, am I too late?

A: As long as the shrubs remain dormant, you are good to go. Look to be sure growth has not already resumed. Bud swell is a good indicator that your shrubs (different shrubs resume growth at different times) are starting. That does not mean you cannot prune, it may limit how much of the branching structure you are going to be able to thin. Except for something early like Alpine currant, most other shrubs found in a typical home landscape should be fine yet, just do not wait too long.

A home orchard management reminder – Dormant oil sprays should be going on while temperatures are going to remain above freezing for at least 24 to 48 hours. We are having those kinds of windows right now and fruit trees need to be completely dormant so there is no injury.

Have a question for the Master Gardeners? Residents can contact the Kendall County Master Gardener volunteers on Monday, Wednesday, and Friday from 9 a.m. to 12:30 p.m. by calling 630-553-5823, stopping in at 7775B IL Route 47, Yorkville, or emailing For helpful hints on what to include in your email, please visit