Rocketman – posted 30 July 2001 10:27
I’m trying to determine the best way to establish a new bahia lawn (.5 acres). The two options I’m entertaining are seeding with penkated bahia or laying sod. Cost and relibility are factors. Any additional information will be greatly appreciated!!
seed – posted 31 July 2001 17:19
Rocketman, in my opinion, bahiagrass seeding can be done very effectively through August in Florida and will give at least as good a stand as sodding, but it takes time and diligence. One advantage of seeding bahiagrass are that you know what you are getting, preferably pure Argentine for most of Florida, but Pensacola for north Florida and any area farther north. Another advantage of seeding is that you have greater control over the level; you won’t be introducing thatch and have bumpy pieces that people will be tripping over. The first disadvantage of seeding is that it takes about one year for a seedling bahiagrass stand to be mature enough to take moderate traffic and look like a rough lawn. Secondly, if there is a significant weed problem in the area, especially noxious subterranean grasses like torpedograss and common bermudagrass, the sod will act as a temporary barrier, while the encroachment into seedlings will be considerable. Annual weeds will also be a problem for seedling bahiagrass, but you manage that by proper seedbed preparation and a few other tricks (below). The third disadvantage of seeding is that if it is a sloped area, there can be unacceptable erosion. This is why the DOT uses the seed (of Pensacola, because for them it’s affordable) on the flat areas, and they use the sod (of Argentine, because it has a better knitted root system) on the slopes and the edge of the road shoulder.
By proper seedbed preparation I mean especially a clean surface free of green vegetation, free of thatch, the object being to get the bahiagrass seed into and underndeath the soil by about 1/4 inch. You can’t accomplish that if there’s a lot of trash. Small rocks and debris are no much of a problem, and proper seedbed preparation does not require deep rototilling; why bring up problems to the surface? If it’s a deep (at least 7 inches) sandy soil, and in full sun, bahia will generally perform well throughout Florida and most of the southeastern United States. When you prepare the bahiagrass seedbed, it’s nice to leave it a little rough, so when you rake or drag that seed into the soil, it actually has depressions to fall into. Seed left on the surface does not germinate successfully, in my experience, which is why hydroseeding of bahiagrass has sometimes performed miserably.
Other tricks of proper seeding are to chop in about 2 tons of straw per acre, if possible using a disk to cut about half the straws into the ground, so they will stick up straight and hold together the horizontal straws from moving around. Hay may be a lot more readily available, but in my experience it doesn’t do as good as straw. By straw, I mean the stems left after harvesting wheat, preferably, or even rye, though that one will germinate on you more that wheat. A typical bale of straw is about 80 pounds, so theoretically you would need about 25 bales to do your half acre.
Repeated studies have shown that millets such as red millet and brown millet are very bad companions for bahiagrass. Millets are warm summer plants, just like the bahiagrass, and they rob the bahia from its only time to establish. The temptation to throw a little millet in to protect the slow-growing bahiagrass seeds is really a guarantee of failure.
My best results (and all of this is published) have been from fertilizing bahiagrass seedings about 5 weeks after planting, or when the seedings are just beginning to form tillers or side shoots. They might have at least 3 leaves at this time. If you fertilize too soon, you will only help the weeds.
Whether you use Penkoted seed or whatever is really a matter of availability. If seed has been stored properly (not on the top shelf of an uninsulated warehouse where it’s going to cook) it should be fine at least one year after harvested, and any seedling diseases should be minor as long as you don’t overwater.
I have always gotten bahiagrass to establish fine in Florida on natural rainfall (during warm weather only). Late in the season, it might be appropriate to irrigate a little at least to prevent the seedlings from drying out too much, because that will slow down establishment. The bahiagrass seedlings are so slow, and so weak and tender looking, that it’s amazing they ever form a dense, traffic resistant stand. But their worst vulnerability is from shading by weeds, most of which love irrigation and fertilization. You can hurt bahiagrass more by babying it. Except, don’t let the weeds get away on you. Whenever the weeds start to overtop the bahia it’s time to mow, and that’s about the only thing you can do. Technically, older bahiagrass should take the phenoxy herbicides like 2,4-D and its mixtures, but they are only good against the broadleaf weeds that the mower will do a good job on, anyway. For grassy weeds, which are more serious, there is effectively no chemical treatment anyway that’s safe on bahia, so again you mow.
The Argentine seed has longer dormancy than Pensacola; in both cases, seed should germinate promptly if it’s a year old and has been stored at room temperature, but Argentine stored in the refrigerator can have considerable dormancy even a year after harvest, and this year’s seed crop may be really slow, and not germinate until next year, unless it’s been scarified somehow.
I may think of some more things, or you can ask them here and I’ll try to get back soon.
[This message has been edited by seed (edited 31 July 2001).]