Have you recently installed new sod on your backyard lawn and are looking for ways to boost its growth and overall health? Looking to spur new turf growth by applying fertilizer, but are worried about doing it too soon? While feeding newly-established sod with nutrients can be beneficial towards grass growth, it can also be very detrimental to the health of your turf if undertaken at the wrong time or season. Which is why homeowners need to carefully consider when to fertilize their new turfs.
In this blog article, we discuss whether fertilization o new sod is advisable, how long you should wait before feeding new sod, what are the best seasons for fertilization of newly-installed sod, and whether the use of starter fertilizer on new sod is advisable. We also take a look at the most suitable fertilization calendar for specific turf-grasses: including St. Augustine grass, Bermuda grass, and Zoysia grass.
Should you fertilize new sod
Yes, you should fertilize new sod, as it’s beneficial to root establishment. With a deeply-rooted turf, your lawn stands a high chance of maintaining its lush appearance for long. However- you’ll want to avoid over-fertilizing your soil, as this will most-likely lead to sod-damage. To find out whether you’ve overfed your new sod with nutrients, check for crusting of the fertilizer on the ground surface. Additionally, check whether you have brown or yellow spots on your grass blades, as this is one of the common symptoms of a nitrogen burn. Finally, if growth suddenly stunts post-fertilization, it’s an indicator of over-fertilization.
To correct over-fertilization of your recently-established sod, thoroughly water the lawn for consecutive days to wash out the excess salts. This will help speed up fresh growth to replace the nitrogen-burnt grass. In some instances, however, the roots are usually already damaged beyond salvation; and even watering can’t help. If this is the case, replace the affected sod areas by raking and pulling them out; then proceed to re-sod the area. After re-sodding, ensure to water the entire lawn regularly to boost your chances of achieving fresh growth.
When to fertilize new sod
The best time to feed new sod with fertilizer is about four-six weeks post-installation. This allows enough time for root anchorage, such that the root systems would be developed enough to absorb the nutrients. In terms of seasons of the year, the best time for fertilizing newly-installed sod is late spring through early fall. When fertilizing new sod on your lawn, consider the following:
- Whether you’re using regular fertilizer or starter fertilizer, ensure to apply enough fertilizer to contain at least half-a-pound of nitrogen. Check manufacturer’s labelling for fertilizer formulation.
- Ensure to water your turfgrass immediately after applying fertilizer, as this will aid the absorption of the nutrients to the sod’s roots. What’s more, it minimizes chances of root burn to the sod roots that consequently causes browning of the grass blades.
- The second fertilization should only be undertaken once the root system is fully established, typically from the sixth week after establishment. In addition, you should cut down on the nitrogen content during this subsequent fertilization, as established sod doesn’t require excessive nitrogen nutrients. An appropriate amount would be about a pound of nitrogen for every 1,000 square-feet of turfgrass-covered nitrogen.
When to fertilize new St. Augustine sod
For newly-installed St. Augustine sod, fertilization isn’t usually necessary until about four weeks post-installation. Fertilizing any sooner than that doesn’t help the grass, as the roots are still typically too shallow at this stage to absorb the excess nitrogen and phosphorus nutrients infused into the soil. What’s more, these excess nutrients contribute towards environmental degradation by affecting the quality of local groundwater.
Being a warm-season turfgrass, the most appropriate time to fertilize newly-grown St. Augustine grass is in mid-spring when chances of frosting are very minimal. You should, therefore, install your St. Augustine sod in early spring to align with this recommended fertilization season. After the initial fertilization, you should continue fertilizing your St. Augustine turf at two-month intervals. Additionally, you’ll want to avoid fertilizing your St. Augustine grass from the start of fall until the warm season resumes the following spring.
When to fertilize new Bermuda grass
You can fertilize your newly-seeded Bermuda grass lawns (even within the first week of installation) to great effect, but only with specific types of fertilizers, including slow-release fertilizers, organic fertilizers, or starter fertilizers. ‘Weed and Feed’ fertilizers- on the other hand- aren’t recommended. You should then hold off subsequent fertilization until about a month or two after the Bermuda grass seeds germinate. Avoid using starter fertilizers for these subsequent applications, as their high phosphorus content is a significant contributor towards groundwater pollution. Finally, you’ll want to avoid fertilizing your new Bermuda grass lawn in early spring, as there’s still the possibility of frosting, resulting in turf damage.
When to fertilize new Zoysia grass
You can start feeding your new Zoysia grass sod with nitrogen-laden fertilizer approximately one-and-a-half months after installation. Starter fertilizers that are packed with essential nutrients like nitrogen and potassium are usually a great option. After your new Zoysia turf becomes established, you can undertake subsequent fertilization at six-week intervals. Being a warm-season turfgrass, the recommended fertilization season for Zoysia grass is from spring to early fall.
Can I put starter fertilizer on new sod?
Starter fertilizer is specifically formulated for use on new sod whose root systems aren’t yet established. Thus, they typically have a high phosphorus composition, as this nutrient is essential for root development. Therefore- it’s okay (and perhaps- important) to apply starter fertilizer on new sod. Still, you should ensure to follow manufacturer’s recommendations when applying starter fertilizer to avoid overfeeding the grass and consequently degrading the soil. Also, you can have your lawn soil’s phosphorus levels tested prior to sod installation; as you don’t want to apply a phosphorus-laden starter fertilizer on soil that’s already rich in the same nutrient.
If you’re working on a budget and can’t get your soil phosphorus levels tested, or maybe your region lacks a local agricultural extension office to help you with the same, you can adopt the guidelines of Peter Landschoot, a renowned turfgrass science tutor at Penn State Extension. Mr. Landschoot recommends the application of a-half to one-pound of nitrogen per 1000- square feet of sod area. Anything exceeding this and you’re liable to scorch your developing turf, or at least stunt its growth. Finally, if your soil test results note that your lawn soil is deficient in key nutrients like potash, application of a starter fertilizer might not solve this problem.