Agronomy – Growing Turf from Seed
Congratulations avid golfers for making it through another Texas summer! I know we still have to endure some hot weather in September. But the days are getting shorter and the nights are getting cooler, so soon we will arrive at some of the best playing conditions of the year.
I received some pretty good questions at our last Greens Committee meeting, and with a few newer members, the question of the month was this: what do I need to do to seed my lawn (successfully)? Before we get deep into the question, I wanted to point out that on established turf we are entering the fall pre-emergent season, so you will want to have your pre-emergent herbicide down soon. For more details, go to www.myavidgolfer.com, click on the September 2021 issue and head to the Ask the Superintendent article, where we cover everything you need to know about Fall pre-emergent applications, including how to calibrate a rotary spreader. Remember that if you are planning to seed even parts of your lawn, you should avoid pre-emergent until the label says it’s safe to apply to new lawns.
That said, let’s take a closer look at some key terms, tips and timing for successfully seeding your lawn, including the dreaded seed-buying process.
Getting Started (Do Your Homework)
It is important to know what type of turf grass you want for your lawn before you start buying seed and note that some turf varieties are not available in seed and are either sodded or sprigged. The most common turf grass types in North Texas include Bermuda grass, zoysia grass, Saint Augustine, centipede grass and fescue, to name a few. Each type of grass has different light, soil and fertility requirements, as well as growth and environmental factors, so knowing that you have picked the best suited grass for your lawn’s environment is important. Understand that we have warm season grasses such as the Bermudas, and they are active in the warm-season months and go dormant in the winter. So if you want green grass year-round, think about a cool-season grass such as fescue. Note that cool-season grasses are seeded in spring or late fall, and warm-season grasses are seeded in late spring and summer. You could, of course, over-seed your warm-season base grass with a cool-season cover grass such as rye grass, which is usually done in September/October.
Another rule of thumb is to know how much light your lawn actually gets (shade from trees or buildings is a factor). We usually want to see a minimum of eight hours of sunlight. Zoysia and Saint Augustine can handle more shade than most Bermuda grasses, but sunlight is still a requirement. Sunseeker is a great phone app to confirm the amount of sunlight in a given area. If you are unsure about what type of turf to choose, you can do some internet research or call a local turf or landscape expert (always check references) for a consultation. Most of the time these consultations/estimates are free, but be sure you confirm this in advance.
Once a type of turf is selected, it’s time to buy the seed.
General Seed-Buying Tips
Seeding is generally cheaper than sod, but it takes longer for the turf stand or sward to establish. However, if you have the patience, you can save some money and still have a great lawn. First you must buy the seed and that takes some effort, but it’s easier with some insider knowledge. A couple of helpful terms include: a seed blend is a blend of grass seed consisting of two or more cultivars of the same species. In other words, combining blackjack and Sahara Bermuda grass would be considered a blend of grasses. A seed mix is when you combine two or more species of grass seed, such as fescue and rye grass in a single bag. And, of course, the traditional single variety bag of seed contains only one variety of seed, such as Kentucky 31 tall fescue.
When you buy turf grass seed, there are four classes of seed usually offered; they are:
Breeder Class: which has no detailed Information Tag and is usually the cheapest.
Foundation Class: has a White Information Tag, which means it is one generation away from breeder class seed.
Registered Class: has a Purple Information Tag and is two generations away from breeder class seed.
Certified Class: has a Blue Information Tag and is three generations away from breeder class seed.
The color and certification class on each seed tag will indicate how many generations away from the original seeded cultivar developed by the plant breeder. Information provided on the seed certification tag must include class of certification, kind of crop, variety, lot number, and name and address of the owner. The lot number will allow the end-user to trace the plant material to the original grower and field. This is important for contamination and inaccurate plant material issues that may arise. Blue Tag seed is obviously the highest quality of pure live seed (PLS) with the lowest percentage of other seeds and miscellaneous filler per bag. You tend to get what you pay for, so remember you are buying potential plants, so get the best seed that you can afford.
For the avid lawn care expert, you can calculate PLS value by completing the following to determine the amount or percentage of PLS in a seed bag. Use the following formula: %purity x % germination = %PLS. For example, a one-pound bag of Bermuda grass seed might contain the following information: purity = 85%, germination = 75% or .85 X .75 = .6375 or roughly 64% of the bag will yield the desired turf grass plant with proper growing conditions. These calculations can help you pick the best value of available seed options.
Seed Bed Preparations
After you have bought your seed, you have the green light to start preparing the seed bed. If you are over-seeding or inter-seeding, you may only need to do a light aeration or vertical mowing to prepare the seed bed. But if you are starting from scratch with a new lawn or doing a lawn renovation, there are a few more steps. Here is a step-by-step guide to preparing your lawn for seeding (note: you have already chosen the seed and timed the application properly).
Test Your Soil You can get all the information about soil testing, including how to take a proper soil sample, at this website: http://soiltesting.tamu.edu. So no excuses. The soil report will tell you what fertilizers and amendments to use and at what rate to establish or maintain your lawn. Be sure to note the type of turf in the crop area of the sample bag.
Remove all existing weeds. Use a sod cutter or shovel or a combination of herbicide and mechanical removal, but remove all of the undesirable vegetation from the area before you apply your seed.
Till or cultivate the top three to four inches of soil. This step is critical to success. Add amendments as directed by soil tests and incorporate them consistently into the soil; this will provide a better growing environment for young turf roots.
Finish grading. Level as needed with a hand rake and prepare the soil surface for seeding.
Apply seed and starter fertilizer (high Phosphorous product such as 18–24–12) use a rotary or drop spreader depending on the size of the seed; seeding rates vary so confirm how many pounds of seed and fertilizer are recommended per 1,000 square feet of area.
Apply straw/hay mulch to protect and keep the seed moist while it prepares to germinate.
Water in seed and fertilizer. Water heavily but avoid runoff/erosion, watering multiple times per day depending on weather, and do not let the seed dry out once you start watering. Maintain even moisture until roots and shoots have established and then begin normal maintenance.
Do not mow until the turf is completely established, and never remove more than ⅓ of the leaf blade in a single mowing.
There you have it, avid golfers. Now you can boldly plan a lawn-seeding project with confidence. Best of luck as we enter the fall seeding and golf season (fall officially starts on September 22 this year), and may the grass always be greener on your side of the fence.
Be sure to thank your golf course superintendent for another great summer golf season and, of course, keep reading AVIDGOLFER magazine.