Choosing the right grass for your lawn can feel overwhelming. Two of the most popular choices, especially in transitional and southern zones, are tall fescue and St. Augustine. Understanding the key differences in a tall fescue vs st augustine comparison is the first step to a healthier, more beautiful yard.
This guide will help you compare these grass types effectively. We’ll look at climate needs, maintenance, appearance, and how they handle challenges like shade and foot traffic. By the end, you’ll know exactly which grass is the champion for your specific lawn conditions.
Tall Fescue vs St Augustine
Let’s start with a broad overview of these two distinct grasses. Tall fescue is a cool-season grass, while St. Augustine is a warm-season grass. This fundamental difference dictates almost everything about them, from where they grow best to their yearly cycles.
Climate and Geographic Suitability
Your local climate is the most important factor in this decision. Picking a grass suited to your weather patterns is the easiest way to ensure success.
Tall fescue thrives in cooler regions. It’s a top choice for the “transition zone,” that challenging band across the middle of the United States where both hot and cold extremes are common.
* Best for: USDA zones 4-7, and higher elevations in zone 8.
* Temperature: Prefers temperatures between 60-75°F. It stays green in cool fall and spring weather.
* Winter: It retains its color late into fall and greens up early in spring. It can handle frost and freezing temps better.
St. Augustine is a grass of the warm, humid south. It loves coastal areas and thrives in heat that would stress other grasses.
* Best for: USDA zones 8-10, especially along the Gulf Coast and the Deep South.
* Temperature: Loves hot weather, ideally between 80-95°F.
* Winter: It goes fully dormant and turns brown after the first hard frost. It greens up again in late spring when soil temps warm consistently.
Appearance and Growth Habit
How do you want your lawn to look? The visual texture and growth patterns of these grasses are quite different.
Tall fescue has a clumping growth habit. It grows in bunches, which allows it to be seeded easily. Its blades are wide, coarse, and have a distinctive ridged texture. The color is a deep, dark green. Because it grows in bunches, it can sometimes look a bit rougher or less uniform than sod grasses.
St. Augustine, in contrast, spreads aggressively via above-ground runners called stolons. This creates a very dense, carpet-like lawn that feels soft underfoot. Its blades are wider than tall fescue’s and have a rounded tip, giving it a lusher, almost tropical appearance. The color is a medium to blue-green.
Shade Tolerance
If your yard has trees or structures that cast shade, this is a critical category.
St. Augustine is the clear winner for shade tolerance among warm-season grasses. It can handle moderate to partial shade remarkably well, though it still needs 4-6 hours of direct or filtered sun to truly thrive. In deep, full shade, it will thin out.
Tall fescue has good shade tolerance for a cool-season grass. Certain varieties, like the “turf-type” or “dwarf” tall fescues, are bred specifically for better shade performance. However, it generally needs more sun than St. Augustine to stay thick and healthy, preferring at least 4 hours of direct sunlight.
Drought and Water Needs
Water availability and conservation are key concerns for many gardeners.
Tall fescue has a deep root system, which makes it relatively drought-tolerant once established. It can survive dry periods better than other cool-season grasses like Kentucky bluegrass. However, during summer heatwaves in its region, it will require consistent watering to stay green and avoid going dormant.
St. Augustine has a shallower root system and is less drought-tolerant. It requires frequent, consistent watering, especially in hot, sunny weather. It will show stress quickly through grayish-blue leaf blades or footpringing (where footprints remain visible). In times of water restriction, it is quick to go dormant.
Maintenance and Care Requirements
Consider how much time and effort you want to invest in lawn care. Their needs vary significantly.
Tall Fescue Maintenance:
* Mowing: Mow high, typically between 3-4 inches. This helps shade the soil, conserve moisture, and promote deep roots.
* Fertilizing: Requires regular feeding in the spring and fall, its peak growing seasons.
* Thatch: It is not prone to building up a thatch layer.
* Establishment: Can be established from seed, which is very cost-effective for large areas. Overseeding in fall is common to repair thin spots.
St. Augustine Maintenance:
* Mowing: Mow at a medium height, usually 2.5-4 inches. Cutting it too short can damage the stolons and invite weeds.
* Fertilizing: Needs regular feeding during its active summer growth period.
* Thatch: Can develop a problematic thatch layer over time, which may require dethatching.
* Establishment: Almost always established from sod, plugs, or sprigs. It produces very little viable seed, so seeding is not an option.
Traffic and Wear Tolerance
Think about how you use your lawn. Do you have kids, pets, or host frequent gatherings?
Tall fescue has very good wear tolerance. Its tough, individual blades and clumping nature allow it to recover well from moderate foot traffic and activity. It’s a good choice for a family yard.
St. Augustine has poor to moderate wear tolerance. Its stolons run on the surface and can be easily damaged by heavy foot traffic. It’s better suited for ornamental lawns or areas with lighter use. It won’t hold up well to regular sports play or heavy pet activity.
Common Problems and Pests
Every grass has its weaknesses. Knowing the potential issues helps you be proactive.
Tall fescue’s main challenges come in the summer. It can be susceptible to brown patch disease in hot, humid weather. It also faces threats from grubs and armyworms. Choosing modern, disease-resistant cultivars is highly recommended.
St. Augustine has a few notable enemies. It is highly susceptible to chinch bugs, which can cause significant damage if not controlled. It is also prone to a fungal disease called Take-All Root Rot (TARR), which can be difficult to manage. Additionally, the aggressive stolons can invade flower beds and garden edges if not edged regularly.
Making Your Final Choice: A Step-by-Step Guide
Follow these steps to make a confident decision for your lawn:
1. Identify Your USDA Zone. This is your non-negotiable starting point. If you’re in zone 7 or north, tall fescue is likely your only option from these two. If you’re in zone 9 or 10, St. Augustine will be more reliable.
2. Analyze Your Yard’s Conditions. Map out the sun and shade patterns throughout the day. Note any high-traffic areas.
3. Assess Your Commitment Level. Honestly evaluate how much time you want to spend watering, mowing, and fertilizing. St. Augustine generally demands more consistent attention.
4. Consider Your Budget. For large areas, the seed-based cost of tall fescue is much lower than the sod cost of St. Augustine.
5. Visit Local Lawns. Take a walk or drive around your neighborhood. See what looks healthy and green in yards with conditions similar to yours. Local success is a great indicator.
FAQ: Tall Fescue and St. Augustine Grass
Can I mix tall fescue and St. Augustine grass?
It is not recommended. They have opposite growing seasons and cultural needs. When St. Augustine is dormant and brown in winter, tall fescue would be green, creating a patchy look. They would also compete for resources, likely leading to one grass type failing.
Which grass is better for full sun?
Both do well in full sun within their preferred climate. St. Augustine excels in hot, southern full sun. Tall fescue handles full sun in cooler climates but may struggle and require extra water in intense summer heat of the transition zone.
What is the softest grass to walk on?
St. Augustine is generally considered softer under bare feet due to its wider, rounded blades and dense mat. Tall fescue has a coarser, more rigid texture.
How do I get rid of one to replace it with the other?
Transitioning requires complete eradication of the existing grass. This usually involves applying a non-selective herbicide, waiting, and then removing the dead turf (sod-cutting) before installing new sod (for St. Augustine) or tilling and seeding (for tall fescue). The best time to do this is at the beginning of your new grass’s prime growing season.
Which grass grows faster?
During its active season, St. Augustine is an extremely fast-growing grass, often requiring weekly mowing. Tall fescue grows quickly in the spring and fall but slows considerably in summer and winter.
Choosing between tall fescue and St. Augustine isn’t about finding the “best” grass, but the best grass for you. By carefully weighing your climate, yard conditions, and personal maintenance style, you can select a grass that will provide a beautiful, resilient lawn for years to come. Remember, the right grass in the right place is the secret to easier, more enjoyable lawn care.