What do I feed my lawn in the spring?

As spring arrives and temperatures start to warm, it’s time to wake your lawn up from its winter dormancy. Proper spring lawn care, including fertilization, is key to getting your grass off to a healthy start for the growing season. In this article, we’ll look at the best fertilizers and nutrients to feed established lawns in the spring.

Should I fertilize my lawn in spring?

Fertilizing in spring is highly recommended for nearly all lawns. After emerging from winter, grass plants are often starved for nutrients and need an early feeding to rebuild energy reserves. Spring fertilizer also supplies key nutrients to support healthy growth as temperatures rise.

An application of balanced fertilizer in early to mid spring can:

• Provide nitrogen to stimulate growth and greening
• Supply phosphorus to encourage root development
• Deliver potassium to aid drought tolerance and disease resistance
• Build carbohydrate reserves for summer stress tolerance

Without proper spring feeding, lawns may exhibit thinning, slow green-up, increased weed invasion, and reduced ability to recover from summer stresses. Fertilizing in spring is one of the most beneficial things you can do for your lawn’s health all year long.

When to fertilize in spring

Timing your spring fertilizer application correctly is important. You’ll want to feed your lawn when it is first breaking dormancy, which occurs once temperatures have warmed to at least 50-55°F for several consecutive days.

In most regions, the optimal spring fertilization window is:

• Northern states: early to mid April
• Central states: mid to late April
• Southern states: late March to early April

Ideally, spring fertilizer should be applied when daytime highs have consistently reached the 60s, but before temperatures have jumped into the 80s.

Fertilizing too early wastes nutrients before the lawn is ready to use them. Delaying too long misses the critical early season growth window.

What fertilizer is best for spring?

For best results, use a complete fertilizer that contains nitrogen, phosphorus, and potassium (the NPK ratio).

Look for an NPK ratio in the range of:

• Nitrogen (N): 25-50%
• Phosphorus (P): 0-25%
• Potassium (K): 0-25%

This balanced nutrient profile supplies enough quick-release nitrogen for spring greenup, along with phosphorus and potassium to strengthen roots and overall plant health.

Slow-release nitrogen sources are ideal, as they provide a steady feeding that lasts 6-8 weeks. Many products are specially formulated as spring or early season lawn fertilizers.

Some examples of quality spring fertilizers include:

• Scotts Turf Builder Lawn Food
• Pennington UltraGreen Spring Fertilizer
• Milorganite All Seasons Fertilizer
• True Value Lawn Fertilizer

For northern lawns that experience late spring freezes, use a product containing at least some quick-release nitrogen to enable rapid greenup once growth resumes.

In southern lawns, lean toward the higher nitrogen amounts in the range above to provide an aggressive spring feeding.

How much fertilizer to use

Apply spring fertilizer at the following rates:

• Northern cool-season grasses: 1 lb nitrogen per 1,000 sq ft
• Transition zone lawns: 1.5 lbs nitrogen per 1,000 sq ft
• Southern warm-season grasses: 2 lbs nitrogen per 1,000 sq ft

These rates provide adequate nutrition without risk of burning the lawn or leaching nutrients. Going above 3 lbs per 1,000 sq ft is not recommended.

To determine how much product to apply for your specific lawn size, check the percentage of slow-release nitrogen (N) on the fertilizer bag. Then use the following calculation:

Lbs of product needed = Nitrogen desired (lbs per 1,000 sq ft) X Area (sq ft) / % Nitrogen in product

For example, for a 5,000 sq ft northern lawn using fertilizer with 20% slow-release nitrogen:

Lbs of product needed = 1 lb Nitrogen x 5,000 sq ft / 0.20 (20% N) = 25 lbs of product

Always follow product labels for maximum application rates to avoid fertilizer burn.

How to apply spring fertilizer

Spring lawn fertilizer can be effectively applied in several ways:

Broadcast spreader

Using a broadcast spreader or rotary spreader allows uniform coverage over your entire lawn. Calibrate your spreader according to the product label. Walk at a steady pace, making overlapping passes across the lawn to ensure even distribution.

Drop spreader

A drop spreader provides precise application in small areas. It works by dropping the granules directly beneath the spreader in a row. Use a drop spreader for fertilizing odd shaped areas or around landscaping beds.

Liquid fertilizer

Liquid lawn fertilizers can be sprayed over the grass using a hose-end sprayer or pump sprayer tank. This offers easy precision fertilization. However, liquid products are more expensive for fertilizing large areas.

Lawn care company

Hiring a professional lawn care service is a convenient option for spring fertilization. Experienced companies know how to time applications for your area and will deliver even nutrient distribution.

Spring fertilizer tips

Follow these best practices for success with spring feeding:

• Mow lawn first so fertilizer reaches soil level
• Apply when grass is dry to prevent sticking
• Water after applying to move nutrients into soil
• Reapply every 6-8 weeks through spring as needed
• Avoid overapplying near wells, storm drains, water bodies

Other nutrients for spring lawns

In addition to nitrogen, phosphorus, and potassium, the following nutrients can also benefit spring and early season lawn growth:

Sulfur

Promotes greening and efficient nitrogen use. Look for fertilizers containing sulfur.

Iron

Enhances green color and aids growth. Apply iron supplements or fertilizer with iron.

Calcium

Strengthens turfgrass against heat and drought stress. Gypsum provides a calcium boost.

Magnesium

Aids chlorophyll production and root growth. Epsom salts can supplement magnesium.

Should I dethatch or aerate before fertilizing?

Dethatching or aerating your lawn before spring fertilization is wise if you have significant thatch or compaction issues. Thatch is a spongy buildup of dead grass stems and roots. It prevents fertilizer from reaching the soil and can lead to fungal issues.

Core aeration creates small holes in the soil to improve air, water and nutrient movement. Spring is an ideal time to dethatch or aerate cool season northern grasses before fertilizing.

However, dethatching and aerating are not mandatory steps before fertilization. A basic mowing is sufficient preparation in most lawns.

Use weed control along with spring fertilizer

Applying pre-emergent herbicides in early spring before fertilizing is smart. Pre-emergents create a chemical barrier to prevent crabgrass, foxtail and other summer annual weed seeds from germinating. This provides weed prevention to complement the benefits of fertilization.

Broadleaf herbicides can also be combined with liquid fertilizer applications. Look for weed and feed fertilizer products to accomplish both jobs at once.

Overseed in spring for thicker lawns

Spring is a prime time to overseed warm season grasses or thin areas of cool season turf. After applying fertilizer, spread grass seed over the lawn. The starter fertilizer provides ideal growing conditions for grass seedlings.

Overseeding fills in sparse regions to create a thicker lawn. Rake seed lightly into soil before watering.

Conclusion

Fertilizing in spring provides a strong foundation for a healthy, thriving lawn throughout the growing season. Apply a balanced fertilizer high in nitrogen when temperatures warm consistently above 50 degrees Fahrenheit and the lawn begins breaking dormancy. Slow-release nitrogen sources ensure a steady nutrient supply. Combining spring fertilizer with pre-emergent weed control, broadleaf herbicides and overseeding generates a synergistic effect for enhanced lawn performance. With proper early season feeding, your lawn will enter summer with the vibrant, green carpet you desire.