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Turf Tips: Controlling Winter Weeds

This post was originally published in March 2017 and was updated with new product recommendations on April 2, 2021.

David Yost, Merrifield Plant Specialist and Turf Expert

Spring is just around the corner. Before long you’ll be sowing grass seed, applying fertilizer, and mowing the lawn! To return your lawn to a thick, healthy state, March is the time to begin controlling pesky winter weeds currently taking over your lawn, and preventing summer weeds.

Winter weeds include chickweed, bittercress, henbit and deadnettle, as well as perennial weeds, such as clover, dandelion and wild violets. These winter weeds actually germinate in late September and early October, but they often go unnoticed in the fall when they’re just young seedlings. They overwinter as a small rosette, and come spring they are ready to strike with a vengeance!

Winter weeds typically flower in March, but can start blooming in February if temperatures are warm! Regardless of when they bloom, you can stop them dead in their tracks with the right control product.

Products to Control Winter Weeds

Two of our recommended products for Trimec Speed (a new product from Gordon’s for residential use, comparable to Speed Zone, their commercial product), and Bonide Weed Beater Ultra. Generally speaking, liquid weed killers are ideal for controlling actively growing weeds because they typically provide better surface area coverage than granular products. Plus, since they are applied as a spray, they can be turned on or off as needed, limiting waste or overuse.

We really like Speed Zone as it contains the same three active ingredients as the other products, but also has Carfentrazone, which makes it work faster and be effective at lower temperatures. Speed Zone also has a two-week waiting period before reseeding the lawn, compared to the three-week waiting period that most of the other products require. This allows you to get started on your overseeding project sooner so that you will be growing thick and healthy turf.

Most winter annuals can be controlled with just one application of weed killer. However, because perennial weeds live year-to-year with an established root system, some of them may be more difficult to control than others. Clover, for example, can typically be controlled with just one application, while others, such as wild violet, may take several applications to effectively control.

Regardless of the weed control product you use, none of them will hurt your lawn if they’re used as directed. Be sure to treat any existing broadleaf weeds in the lawn now, so that you’ll be ready to start building a beautiful new lawn from a clean slate.

Lawn, Grass, Turf

Spring Lawn Care Checklist

Now is the time to get your lawn in spring shape! The weather is warming up, trees are starting to bloom, and healthy, dark green grass can really contribute to the feeling that spring has arrived. By taking a few steps, anyone can refresh their lawn for a beautiful spring landscape. Before starting your lawn refresh, remember that each one is different and your lawn’s care needs will be unique to the conditions it is under as well as its current state. If you need any assistance deciding which of the steps apply to your lawn, please call one of our experts at the plant clinic or stop by and see us.

Control Winter Weeds

March is the perfect time to control and eliminate any winter weeds that crept into your lawn over the season. Chickweed, bittercress, henbit, deadnettle, clover, dandelion and wild violet are all weeds that may be seen at this time.

Check out our blog post on eliminating winter weeds.

Prevent Summer Weeds

After treating winter weeds, it’s a good idea to pre-treat for summer weeds. Preventing their germination from the beginning will save you a lot of trouble, and help you maintain a weed-free landscape throughout the season. Common summer weeds include crabgrass, goosegrass, foxtail and Japanese stiltgrass. When planning your weed prevention, you will want to take into account whether or not you will be seeding your lawn.

For full information on preventing summer weeds, visit our summer weed prevention blog.

Seed and Fertilize

Take advantage of the spring season to fill in your lawn by overseeding. This is a great opportunity to select new seeds that will work great in your lawn’s conditions. We offer many varieties and are happy to help you select one that will thrive in your landscape. When you are seeding, fertilize your lawn as well with a high phosphorous formula.

For complete steps and our recommended products, check out our seeding and fertilizing blog.

Pruning, Winter

Getting Your Garden into Spring Shape

Spring is almost here and it’s time to start getting our gardens ready for the season. As you plan your March and early April gardening projects, here are some tasks you may need to complete.

Ornamental Grass Pruned

Prune Perennials and Shrubs

Cut back the old, browned growth of perennials and groundcovers and trim the leaves of grasses and liriope back to almost ground level. Removing the old growth will make way for fresh, green growth that will emerge this spring. Remove old stems of sedum, coneflower, chrysanthemums and other perennials back to where the new buds are beginning to emerge. This will help keep your perennials full and stocky while giving your garden a fresh look. After cutting back your perennials, thin boxwoods and prune hollies and yews. Needled evergreens such as junipers and cypress can be lightly sheared or thinned, but avoid any extensive pruning. If you prune back into the old growth on these plants, they will not fill back in. This is also a great time to prune crape myrtle, roses and other summer blooming shrubs, with the exception of bigleaf and oakleaf hydrangeas. Avoid heavy pruning for these plants, as this will interfere with their flowering. If you are looking for more detailed information on pruning times and methods for some of our most popular landscape plants in our northern Virginia region,check out our tree and shrub pruning guide.

Clean Up Landscape Beds

Give your landscape beds a professional look using a spade or edging tool to define borders with smooth, sweeping curves or straight lines. After this is complete, add fresh mulch to protect and improve the soil, conserve moisture and discourage weeds. There are several different types of mulch to choose from, and they all do a good job. Pick the one with the color, texture and price that suits your taste. As a note: never layer more than 3 inches of mulch in your landscape beds – it is possible to have too much of a good thing!

Eliminate Weeds

Get ahead of the weeds! As you are cleaning up your established landscape beds, pull out any weeds that crept in this winter and apply a weed preventer. Weed preventers create a chemical barrier in the surface of the soil to inhibit germinating seeds from becoming established. Just be sure not to use weed preventers in any beds where you will be adding new plantings this spring. For more information check our blog posts on treating winter weeds and preventing summer weeds.

Prepare Garden Beds for New Plantings

Amend the soil of garden beds where you will be adding new plantings with fertilizer and soil conditioner. We recommend using Merrifield Starter Plant Food for your fertilizer and Merrifield Planting Mix for the soil conditioner. Preparing beds now will make it easier and more enjoyable when you are ready to start planting.

Plant Cold Hardy Trees, Shrubs, Perennials, Vegetables and Annuals

You can begin planting cold hardy trees, shrubs, perennials, vegetables and annuals. Be aware that we will continue to have freezing temperatures and frosty mornings throughout our area until late April. If you have plants with tender new foliage or flowers, be prepared to cover them with a frost cloth on those cold nights and days. Pansies, violas and primroses will all provide spring color, but are cold tolerant and can handle the chill of early spring. We get new plants all the time, so you can always stop by and ask our plant specialists about what will work well in your garden. Improve the growth, color and flowering of your favorite garden plants by fertilizing now as the growing season begins. We have made this super easy. If you want to promote blooms, use Merrifield Flowering Plant Food, if you want to promote lush, green vegetative growth, use Merrifield Tree and Shrub Food.

If you have any questions about preparing your garden for spring, give us a call, email us at service@mgcmail.com, or drop by the store and talk to us!

Turf Tips: Preventing Summer Weeds

David Yost, Merrifield Plant Specialist and Turf Expert

Untreated summer weeds have a way of wreaking havoc on our lawns. The good news is that they haven’t germinated yet. You can intervene in the process by applying a summer annual weed preventer now. If you haven’t already, you’ll want to start by treating any winter weeds that currently reside in your lawn.

Types of Summer Weeds

Summer weeds include varieties of grassy and broadleaf weeds. Grassy weeds include crabgrass—the most infamous of all—goosegrass, foxtail and Japanese Stiltgrass. Japanese stiltgrass is now the most common weed in the state of Virginia. Each of these plants produces over 1,000 seeds that will remain viable in the soil for 3 to 5 years.

Many broadleaf weeds begin germinating in early spring and include spotted spurge and lespedeza, among others. Regardless of what type you have, all of these will stick out like a sore thumb in an otherwise healthy and attractive lawn.

Preventing Summer Weeds

To determine which product you should use to prevent summer weeds from attacking your lawn, you must first decide if you are going to seed the lawn this spring.

If you’re not planning to seed the lawn

If you are not seeding the lawn this spring, there are three different products you can use to control summer weeds:

  • Preen Crabgrass Control
  • Organic Corn Gluten

Preen Crabgrass Control contains dimension, a very effective ingredient that prevents summer weeds. Both products will remain active in the soil for 2 to 3 months, which means you need to put down two applications per year (for example, one in mid-March and another in early June).

Corn gluten is an organic weed preventer, which naturally inhibits all seed growth. This product will last about 1 to 2 months in the soil, which means you need to put down two applications per year (for example, one in mid-March and another in late April or early May).

If you put down two applications of any of these products in the spring and early summer, your lawn will be ready for fall seeding. Fall is an ideal time to seed as the warm days and cool nights provide the optimal growing conditions for cool season grasses.

If you are planning to seed the lawn

If you are seeding the lawn this spring, we recommend using Scott’s Step 1 for Seeding (Starter Food with Weed Preventer). This product contains tenacity, an ingredient that can distinguish between the “bad” summer weed seeds and the “good” grass seeds. This product also provides starter fertilizer to help your grass seed germinate.

Once your new grass seed has germinated and been mowed twice (this typically occurs about 6 to 8 weeks after seeding), you can apply a second application of another summer annual weed preventer. For the second application, we recommend using one of the three products for not seeding your lawn. By this point, your new grass will be mature enough to withstand the dimension ingredient. You should only use the Scott’s Step 1 for Seeding for the primary application as your lawn doesn’t need a second application of the starter fertilizer that comes automatically in the product.

Lawn

Treatment for Summer Grassy and Broadleaf Weeds

David Yost, Merrifield Plant Specialist

In our area, our lawns are the happiest when the temperature is between 50 and 75 degrees F and they get about an inch of water per week. With the soaring temperatures and lack of rain we encountered in July and August, our lawns are way out of their comfort zone! Stressed, thin lawns become vulnerable to weed takeover.

The last few weeks we’ve seen lawns mostly struggling with summer annual grassy and broadleaf weeds. these include crabgrass, Japanese stiltgrass, spurge and lespedeza. This a good time to treat these weeds and get ready to restore your lawn as the ideal time for seeding is right around the corner.

Crabgrass

Crabgrass

Spurge

Spurge

Japanese Stiltgrass

Lespedeza

Lespedeza

Treatment

If you’re struggling with grassy weeds, such as crabgrass and Japanese stiltgrass, we recommend Bayer Advanced Bermudagrass Control for Lawns. If you’re struggling with broadleaf grasses, such as spurge or lespedeza and/or grassy weeds, we recommend Trimec Crabgrass Plus Lawn Weed Killer. You can apply either product immediately. Just be sure to wait three to four weeks before seeding your lawn.

If you’re not sure what weed has taken over your lawn, bring a sample into any of our three stores and see a plant specialist at our plant clinic. We’re more than happy to help you diagnose the problem and recommend a treatment plan.

Summer annual weeds can be prevented, but the treatment must take place in the spring. The best way to protect your lawn from summer weed takeover is by maintaining a thick, dense turf.

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