Last week I covered early lawn activities to consider doing now. This week I’ll cover things we should avoid doing, should only do in certain circumstances, or should at least postpone.
To recap last week, items to do were: apply pre-emergence herbicides to control crabgrass, prepare lawn for mowing, perform pre-season lawnmower maintenance, re-seed small bare spots, and mow lawn as needed. After grass begins to grow, additional operations may include thatch control or aeration of turf.
Items to avoid doing include lawn rolling and early season fertilization of turf. Additionally, proper timing of broadleaf weed control may be different than you are used to.
First, don’t roll your lawn. I’ve seen a lot of rollers active already on established turf, so this advice may be a little late. Turf specialists generally do not recommend heavy rolling of saturated or clay soils in spring because it can cause soil compaction and increase soil moisture stress in summer. For most lawns, they will level out on their own in a short time. Rolling should never be used to correct surface undulations caused by improper grading.
Consider that soil contains minerals (sand, silt and clay) and organic matter, but it also includes important pore spaces that hold water and air. Water and air are important for healthy root growth. Compaction through rolling reduces pore spaces and can affect overall soil structure in a negative way. The result is a less healthy environment for roots to grow. Limited roots reduce the potential of the grass plants to be healthy and vigorous throughout the year.
This is also why we love earthworms. Earthworms can have significant impacts on soil properties and processes through their feeding, casting, and burrowing activity. The worms create channels in the soil, which can aid water and air flow as well as root development.
Some special cases where rolling may be justified include lightly rolling newly seeded areas to improve seed-to-soil contact, or rolling newly sodded areas. Severely mole-plagued or frost-heaved yards may justify a light rolling.
Secondly, resist the urge to fertilize now. Early season fertilization can encourage too much top growth at the expense of roots, and could lead to problems later this summer such as poor root growth and disease. Besides, can you keep up with mowing in early spring anyway, when grass grows so vigorously? It is better for homeowners to wait until mid- to late-May (after the vigorous spring flush of growth subsides) and apply up to 0.75 lbs N/1000 sq. ft. with a fertilizer that contains mostly slow release nitrogen sources. If you applied pre-emergent crabgrass controls, most of those products come with a fertilizer carrier – that can’t be helped.
It’s not exactly on the list of things to avoid, but the best time to control dandelions and other broadleaf weeds is in the fall. If you absolutely must treat this spring, homeowners should use a product that has a combination of active ingredients like 2,4-D, MCPP, and dicamba. These products typically give good control of a variety of broadleaf weeds when applied during or shortly after flowering. If you face hard-to-control weeds, such as creeping Charlie (ground ivy) or wild violet, using a herbicide containing triclopyr or fluroxypyr can also be helpful. Follow all label instructions!
For more information, search for the free Purdue Extension publications, Mowing, Dethatching, Aerifying and Rolling Turf, and, Control of Broadleaf Weeds in Home Lawns, at Purdue’s Education Store: www.edustore.purdue.edu. For timely home landscape tips throughout the season, access the Purdue Landscape Report, at https://www.purduelandscapereport.org/.