Why fertilize lawn

Subscribe to the "The Sapling" on the Davey Blog for the latest tips to keep your outdoor space in tip-top shape throughout the year. Our toes love gliding through our lush, green grass. But did you know our lawn does far more than just look and feel good? Lawns also improve air quality, reduce heat by 20 to 30 degrees and generate oxygen. So they can continue creating these perks. One of the best ways to keep grass vibrant on the surface and healthy down into their roots is to fertilize.

And right now is the most important fertilization of the year — not spring! Should you mow first? Wait until after it rains? Or wait until the best time of day to fertilize the lawn? Summer heat is stressful on our lawns.

While fall is naturally good for feeding our lawn, you can deliver an extra oomph by fertilizing as best as you can, too. To find an exact date, look for the first frost date in your area. Sure is! The best time of day to fertilize is in the morning or early evening. A soil test from the University of Minnesota Soil Testing Lab can help you determine if your lawn is missing or has too much of these essential nutrients. Turfgrass usually needs more nitrogen than other nutrients and lawn fertilization programs are based around this nutrient.

Turfgrass gets some of the nitrogen it needs from the soil. However, homeowners may want to add supplemental nitrogen to maintain turfgrass quality that they find acceptable. Below is a table that outlines when and how much nitrogen is recommended for established lawns based on the amount of maintenance required for the lawn.

If soil organic matter level is not known, guidelines for medium soil organic matter can be used. Compost is not included because it has little nutrient value. Composts can be very beneficial as a soil amendment, adding organic matter and improving many soil properties. Natural organic fertilizers are commonly made from waste products of various sources ranging from chicken feathers and manures to treated sewage sludge from city waste systems. Rock phosphate and potash are mined from the earth.

The manufactured fertilizers normally are made from petroleum and natural gas. The exceptions are superphosphate and triple superphosphate, which are rock phosphate that has been concentrated using acid reactions. Whether natural or manufactured, the nutrients in fertilizer are generally not in a form the plant can use directly.

The speed at which nutrients in the fertilizer become available to the plant varies depending on the product. All fertilizers must be broken down to the same nutrient form. All types of fertilizer can contribute to pollution, if used incorrectly. Take special care when using fertilizer-herbicide combinations. Water-in fertilizers following application for maximum effectiveness and to reduce the chance of damaging the lawn i.

Many herbicides, however, need to remain on the plant leaves for effective weed control. Weed-and-feed products often compromise the effectiveness of the fertilizer, herbicide or both during application. Always check the specific product label for any post application requirements e.

Fertilizer-herbicide combination products often apply much more herbicide than is needed to kill the target weeds. Where there are only scattered weeds throughout the yard, it is just as easy to spot treat those individual weeds or small areas of weeds rather than applying a weed-and-feed product over the entire lawn.

Fertilizer-crabgrass preventer pre-emergent combinations contain a weed preventer specifically targeting the tiny seedlings of warm season annual grasses crabgrass and yellow foxtail. The weed preventer works as the grasses just emerge from the seed, but before they are visible above ground. A spring application of fertilizer that contains a crabgrass preventer could be an appropriate choice if you wait until early May. However, crabgrass preventers should be put down much earlier in the spring than fertilizers.

If fertilizers are applied to a lawn too early, the environmental loss of these nutrients can be a concern. Applying fertilizers and crabgrass preventers separately is the best approach. As with most weeds, crabgrass will not likely be uniform over an entire yard. A crabgrass preventer may only need to be applied along those areas where the lawn grasses are not as competitive.

These include areas along curbs, sidewalks, narrow boulevards and driveways. All rights reserved. The University of Minnesota is an equal opportunity educator and employer. Home Yard and garden Lawns and landscapes Lawn care Fertilizing lawns. Quick facts Fertilizers add nutrients like nitrogen, phosphorus and potassium to the soil to help plant growth.

On every bag of fertilizer, you will find an analysis of the nutrients in the fertilizer. Natural and manufactured fertilizers have different characteristics.

Spot treating weeds may be more effective than using a weed-and-feed product over your entire lawn. Fertilizing basics. Open all Close all. Why fertilize? Nutrients are needed by grass plants because of the many stresses people apply to them.

Grass uses nutrients to repair damage done by normal wear and mowing. Other plants in the landscape, such as trees, flowers and weeds, also consume the nutrients. Nutrients are lost when clippings are removed while mowing. What is in fertilizer? Timing is critical for this step. Make sure it's applied before crabgrass seed germinates — that happens when soil temperatures reach 55 degrees Fahrenheit. For best results, apply with a spreader to actively growing turf and give your lawn at least.

On top of weed control, Pennington UltraGreen Crabgrass Preventer Plus Fertilizer III delivers iron and fast-acting nitrogen for immediate greening, and slow-release nitrogen for extended feeding for up to three months. Always follow the label instructions for your specific grass type.

Do not apply this product within 60 days of overseeding. Wait until the following year before treating new sod. Between April and June, existing weeds launch into active growth. For best results, apply the product in the early morning when grass is wet with dew and no rain is forecast for one to two days. After overseeding, wait until your third mowing occurs.

Between June and August, proper feeding helps strengthen lawns against heat and drought. This premium lawn fertilizer, ideal for northern or southern lawns, keeps feeding for up to three months. Your lawn gets essential nutrients, including iron for rich color, and you get thick, lush green grass.

Always check the label for your specific grass type, then follow instructions accordingly. Used as directed, you can apply Pennington UltraGreen Lawn Fertilizer to wet or dry lawns and not worry about fertilizer burn. Between August and November, grass slows down and prepares for the winter months. At the same time, broadleaf weeds start active growth again.

As a general rule, allow six to eight weeks between fertilizing and your first expected frost. As with all fertilizer products, check the label and follow instructions for your specific grass type. Always sweep excess fertilizer off sidewalks and patios to avoid runoff. Whenever you apply fertilizer, always follow best practices for fertilizer safety. For best results, mow your lawn one to two days beforehand.