How to do Summer Weed Control

If they’ve been properly placed in the landscape, veggies, groundcovers and perennials are probably growing quite well at this point in the season.  Even lawns are doing well if the soil beneath has been kept moist, not soggy or dry.  If not, the effect of July’s high temperatures has likely caused them to wilt, turn brown or just look faded instead of vigorous.

 

In addition to the effects of the heat, the tilth of the soil is another important factor in helping plants get through the heat of the summer.  When compost or other organic matter sources are incorporated into the soil when planting these non-woody plants, it makes a huge difference in their health in summer.

 

A good indicator of a vegetable, perennial, annual and lawn under summer stress are the presence of weeds.  As opposed to desirable plants, most weeds don’t need healthy soil and proper placement to grow well, and they sprout up to take their place.  Weeds such as crabgrass, spurge, nutsedge, ground ivy, prostrate knotweed and oxalis seemingly grow wherever they want, in the roughest of conditions.  They commonly thrive in sidewalk cracks, under fences and yes, amongst the plants we like the most.

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So, what can be done in mid-summer?  Several actions can be helpful in limiting their germination and growth.  First, apply a second application of preemergence herbicide.  If only one (or none) has been applied to this point, it’s possible that the sun and rainfall has broken it down to the point where it’s no longer effective.  Be sure to read and follow the label directions for each plant grouping where it is applied.

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Second, apply mulch.  For veggies, scatter an inch of grass clippings between plants; for flowers, a couple of inches of wood chip mulch will do the trick.  A reasonable approach for vegetables and lawns is to rotate between collecting clippings for the garden and returning them for the lawn; that way each part of the landscape receives mulching benefit.

 

The third weed control method is hand pulling, depending on your point of view.  One way to look at hand pulling is that it’s a good first step; the idea is to make a pass through, pull most of the weeds, then rely on mulching and preemergence for the rest.  A big advantage of mulching is that if weeds do germinate in the mulch, they will be much easier to pull from the loose mulch than firm soil.  The other way to use hand pulling is to embrace it as good exercise and repeat it frequently until all weeds are eliminated.  Both approaches work well.

 

John Fech
Horticulture Extension Educator at Nebraska Extension
John Fech is a horticulturist with the University of Nebraska-Lincoln and certified arborist with the International Society of Arboriculture. The author of 2 books and over 200 popular and trade journal articles, he focuses his time on teaching effective landscape maintenance techniques, water conservation, diagnosing turf and ornamental problems and encouraging effective bilingual communication in the green industry. He works extensively with the media to extend the message of landscape sustainability, making over 100 television and radio appearances each year.
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