Turing Dirt Part Four: Finishing and Planting the Seedbed

By Mark Trudeau

In this series of articles, The Whitetail Institute’s agricultural expert, Mark Trudeau, passes along his decades of real-world experience in farming and related matters to our Field Testers. In the first three segments of “Turning Dirt,” Mark provided his insight to help first-time buyers select a food-plot tractor and discussed tractor implements suitable for ground tillage, such as plows, tillers and disks. If you missed the earlier segments or if you would like to review them, they are available on line at www.whitetailinstitute.com under the “Whitetail News” link.

In this segment, Mark discusses implements designed to finish a seedbed and plant it. We started the “Turning Dirt” series of articles in our first issue of Whitetail News for 2007. In that issue, we set out some guidelines to help first-time tractor buyers shop for their first tractors. In the next issue, we talked about plows and issues related to initial ground tillage, and we covered disks and tillers in the third issue of 2007. All these articles are available at www.whitetailinstitute.com

In this segment of “Turning Dirt,” we’ll cover tools you can use with your tractor or ATV to do the next job in the planting process — finishing the seedbed prior to and after planting. This is an important and detailed matter on its own, so we will leave the specific subject of how to put your seed out for a later segment of “Turning Dirt.”

Before we get into the various types of implements you can use to smooth and firm your seedbed, you need to understand what exactly it is that you’re trying to accomplish in this stage of the planting process. In short, you are trying to place your seed at the optimum depth for that particular kind of seed, and in such a way that it will stay there and not get too deep in the soil. That means that you need to know two things: (1) the correct depth at which your seed should be planted, and (2) how to prepare your seedbed so that when you put your seed out, it will stay where you put it. Let’s start out with a summary of appropriate planting depths.


Regardless of which Imperial forage blend you have chosen, you need to make sure that you plant it at the correct depth. How deep that is depends on whether you will be planting “large seeds” or “small seeds.” It would seem at first blush that all seeds are pretty small, but that’s not what’s being described when you hear experienced planters use these terms. Instead, what they’re referring to is the sizes of the seeds relative to each other — in other words, some seeds are smaller (or larger) than others. Knowing whether you are planting a “large-seed” blend or a “small-seed” blend is critical, since seeds in one group should be planted at a different depth than those in the other.

“Large-Seed” Imperial Blends: The Whitetail Institute currently offers two large-seed blends: Power Plant and Pure Attraction. The optimum planting depth for these blends is within an inch under the surface, and covered by loose soil. 

“Small-Seed” Imperial Blends: Except for PowerPlant and Pure Attraction, all other Imperial forage blends are small-seed blends. They can withstand being planted a maximum of 1/4 inch below the surface, but it is optimum to place these seeds in good contact with the surface of the seedbed, so that’s what you should shoot for — placing small seeds in sufficient contact with the surface of the soil.


Now that you know the optimum depth at which each Imperial forage blend is designed to be placed in the soil, you’re good to go, right? You can go out, broadcast your seed, and know that the seed will stay right where you put it, right? Well, maybe . . . but maybe not. Let’s say that your prepared (disked or tilled) seedbed has cracks, but none deeper than one inch. If you will be planting a large-seed blend, then the seedbed is sufficiently smooth. If you’re planting a small-seed blend, though, you have more work to do before you put your seed out.

Remember we said that although they can usually withstand being as much as 1/4 inch under the surface, it is optimumto place small seeds in good contact with the surface of the seedbed? Consider what might happen if you plant your small-seed blend in ground that is very soft, and against our clear instructions drag the field again after planting, and what might happen if a hard rain comes along and drives the seed down 1/2 inch below the surface. That’s too deep — the seedling may not be able to make it up to the surface. That’s why when planting small seeds, you not only have to get the seedbed smooth, but also have to get it firm before you put your seed out.

Seedbed Smoothness: How smooth and firm must the seedbed be? Take a look at the photo below. 

Large Seeds — Seedbed Must Be Smooth Enough. As I mentioned earlier, large-seed blends such as PowerPlant and Pure Attraction should be planted within an inch of the surface, and covered by a thin layer of loose soil. The seedbed shown on the left side of the photo has no cracks that are more than one-inch deep. That is smooth enough for you to plant PowerPlant or Pure Attraction. Make sure you’re clear, though — this area of the photo shows no cracks that are deeper than one inch, which is the minimum smoothness you should shoot for before planting a large-seed blend such as PowerPlant or Pure Attraction. So if you’re planting either of these blends, at least eliminate cracks more than 1 inch deep.

Small Seeds — Seedbed Must be Smooth AND Firm Enough. Remember we said that small seeds should be placed in good contact with the surface of the soil? If small seeds fall into the one-inch deep cracks shown on the left side of the photo, they have a greatly reduced chance of survival. Accordingly, you need to do two things before you plant a small-seed blend — you have to eliminate even small cracks, and you have to get the seedbed firmer before you plant. A seedbed with these characteristics is shown on the right side of the photo.

Small Seeds — How Firm Must the Seedbed Be Before Planting? Remember our example of someone planting small seeds at maximum depth in a soft seedbed and having rain come along and drive the seed too deep? To minimize the chances that seed will be driven too deep by rain or other natural factors, you should try to get your seedbed optimally firmed before planting small seeds. The good news is that’s an easy thing to test for. Just walk out into your seedbed before you plant. Your seedbed will be at optimum firmness if you can just barely see your boot tracks.
Seedbed Firmness — Soil Moisture is a Critical Factor: One of the most important factors that influences how firm you can get your seedbed is soil moisture. If your seedbed is too wet, your implements will clog up as you pull them through the soil. If it’s too dry, then you won’t be able to firm the seedbed very well. Thankfully, this is also an easy test to make. Just form some of the soil from your seedbed into a tight ball with your hand, and then open your hand. Ideally, the ball should hold together for a few seconds and then fall apart. In dry soil, it won’t hold together at all, and in wet soil, it won’t fall apart.


Now that you know how deep the Imperial blend you’ve chosen should be planted, and how firm and smooth your seedbed must be to keep it where it should be, let’s get into various implements used for these functions. They include weighted drags, drag harrows, and cultipackers.

Weighted Drags: These are the simplest tools of the bunch. The ways they can be made are virtually limitless, but however you build one it must do one thing in order to be effective: it must smooth the seedbed well enough to eliminate cracks. There are lots of ways to make an effective drag, however one way that works very well is to start with a piece of chain-link fencing about four-feet by four-feet in size. Lay the fencing down in your plot, place a wooden pallet on top of the fencing, and stack a few concrete blocks on top of the pallet. Presto! You have just built a very effective homemade drag implement!

To attach the drag to your tractor or ATV, weave a piece of rebar or pipe through the links at one end of the fencing. This will give you something strong to attach the drag to your tractor or ATV with a rope or chain. Again, this is just one way to make a homemade drag implement. There are other ways to make an equally effective drag, for instance using an old, heavy farm gate instead of the fencing, pallet and blocks. However you design your drag, though, remember that it has to do one thing well — when it is pulled across the seedbed before seeding, it must smooth the plot. That means it must eliminate cracks and most clods.

Drag Harrows : Drag harrows can perform the drag function of a weighted drag. They have an additional feature, though, that makes them incredibly versatile tools — they have spikes or teeth that extend down from one side of their main frames. There are several different types of spike-tooth harrows. The ones we’ll talk about are the ones you’re most likely to encounter: “spring” or “spike-tooth” harrows, and “fixed harrows.” Since spring harrows are much more common these days, let’s look at those first.

“Spring” or “Spike-Tooth” Harrows: This is the simplest, and perhaps also the most versatile, type of drag harrow and can be used in two ways. They can be used as a “drag,” like the weighted drag I mentioned earlier, or they can be used as a “harrow” to disturb the soil a few inches deep. Let’s look at each feature in greater detail. Spike-tooth harrows are often called “spring” harrows because of the way their spikes, or teeth look. Instead of railroad-type spikes such as were often used on the older, fixed-type harrows, the teeth on spring harrows look like two-pronged springs. Like our homemade fence-type drag, spring harrows are also often built on a mat that looks like ordinary chain-link fencing, but of a much heavier gauge than you’d use to build a fence. Used in this way, drag harrows perform the same function as a weighted drag. In addition, drag harrows can be used to “harrow,” which means to lightly disturb the soil from the surface and down a few inches. They do this with sets of pivoting teeth that extend down from one side of the chainlink mat and are attached in such a way that they pivot within a limited range forward or backward. The teeth are also self regulating as to angle — the angle of the teeth sets itself as you pull the implement across the ground. If you pull the implement from one end, the teeth set themselves at a light angle. If you pull from the other end, the teeth set themselves at an aggressive angle.

When a chain-link drag harrow is used as a drag, it is laid on the ground with the teeth pointed up so that they are out of the way. To harrow, the drag is simply flipped over so that the teeth are down, and then the implement is pulled forward or backward depending on how aggressively the operator wants to disturb the soil. Also, since spring harrows are built on a flexible, “mat” instead of a fixed frame, they tend to follow the contour of the ground better and don’t lift up on one end the way that fixed harrows can when pulled across a small dip or high spot in a field. These features make spring drag harrows one of the most versatile tools available for the food-plot planter to use to accomplish a variety of planting duties, both before and, where appropriate, after seeding.

Before seeding, a chain-link drag harrow can be used to blend lime or fertilizer into a disked or tilled seedbed, and to smooth and firm it. A disk or tiller is often the best implement for doing these jobs, but if you’ve had a farmer come out and disk your field and he’s not available to finish the plot, you can do a great job with a harrow and an ATV. A harrow is also a great tool for covering PowerPlant or Pure Attraction seeds under a thin layer of loose soil.

Fixed Harrows: Fixed drag harrows are not as common these days as they once were. They are built with a hard frame with adjustable spikes attached to one side. The mechanism for adjusting the angle of the spikes is permanently mounted on the top side of the frame, which is why they are called “fixed” — they can’t be flipped over and used as a drag the way a spring harrow can.

Cultipackers: A cultipacker is pretty easy to describe — it’s just a big, heavy roller with ridges and is pulled behind an ATV or tractor. As the cultipacker rolls along, it does several things. Mainly, it presses down on the seedbed’s surface just like ironing a shirt, which helps remove bumps, creases and cracks that seeds might fall into. It also helps firm the soil and eliminate air pockets, which helps the soil retain moisture. The ridges, or “corrugations” in a cultipacker can also help control erosion, especially when used to make horizontal ridges around a sloped plot, and to help hold water in flat plots longer so it can soak into the ground better.


So far in our discussion of weighted drags, drag harrows and cultipackers, we’ve talked about features of each type of implement. Some of these features make one or more implements appropriate for certain plotpreparation functions, and less so for others. The same is true of the implements after you have put your seed out. Let’s look at these in greater detail.

Initial Ground Tillage: None of the implements we’ve mentioned in this segment is appropriate to use for initial ground tillage. They are all light pieces of equipment designed to perform precise work after initial tillage has been accomplished by heavier equipment designed for that function. In fact, if you try to use a drag harrow to cultivate fallow ground, chances are pretty high that the harrow will just bounce along the ground until it catches on something and breaks. So, use finishing implements for what they were designed to do — finish work.

Once you’ve done your initial ground breaking or tillage with a plow, disk or tiller, though, these finishing implements have a distinct advantage for finishing a seedbed. That advantage is that they aren’t heavy. That means that you can pull them with most ATVs, and when using them, you won’t have to go back and cover the deep tire marks you’d be facing if you pulled them with a tractor.

Lime and Fertilizer Incorporation: If a disk or tiller isn’t available, drag harrows are the best choice for this job.

In order for lime to raise soil pH, it must be incorporated, or mixed, with the soil. How deep lime and fertilizer should be mixed depends on what product you’re planting. Some, such as No Plow and Secret Spot, only need lime and fertilizer very near the surface. That’s because these blends contain very shallow-rooted plant varieties.

Imperial perennials and other blends, though, grow more extensive root systems, and if they are to flourish, soil pH and fertility must be adjusted deeper by mixing lime and fertilizer deeper into the soil. That requires initial groundbreaking, when appropriate, with a plow, disk or tiller. If you are among the many folks who hire a guy with a tractor to come out and do the heavy disking or tilling for you, you may not have him handy when the time comes to incorporate your lime or fertilizer. In such cases, you can use a harrow as an alternative and do pretty well. Once the soil has been loosened with heavier equipment, lime and fertilizer can then be blended into the top few inches of soil with a drag harrow.

Smoothing and Firming the Seedbed Before Planting: Any of the implements we’ve discussed in this segment — the weighted drag, the drag harrow or the cultipacker, can do a good job of smoothing and firming your seedbed. One more important thing about drags and harrows — when you’re pulling a weighted drag or a harrow to smooth your seedbed, you should go just a little bit faster, about 5-8 mph. That will increase the impact of the implement against the larger clods and help shatter them better. A cultipacker generally does the best job, since its weight is rolled across the surface instead of dragged, leaving the smoothest surface, again like ironing a shirt.

A critical difference between a cultipacker and the other types of finishing implements, though, is that a cultipacker generally leaves the soil firmer than you can get it with a drag or a harrow. That is critical because it will determine your last planting step.

After Seeding — The Critical Difference: Let’s revisit two extremely important things:

1. Large seeds should be planted under an inch or less of loose soil.

2. Small seeds should be planted in good contact with the soil’s surface. That means that before planting, the seedbed must be both smooth and firm Now it’s time to get, as they say, to the “nitty gritty” — which implement to use for what purpose, and how to use it properly to get the result you want. Once you have disked or tilled your lime and fertilizer into the seedbed, the following guidelines should help you decide what to do and what not to do to perform final seedbed preparation before seeding, and finish the plot after seeding.


Imperial PowerPlant and Pure Attraction Goal: Cover the seed with a thin layer of loose soil.
Implement Used
To Smooth and
Firm Plot Before                                  Action Before                                     Action After
Seeding                                               Seeding                                             Seeding

Weighted                                           Pull implement fast                            Pull implement
Drag                                                   (5-8 mph) over seedbed                    slowly over seedbed
                                                            until clods are broken up,                   to cover seed
                                                           and cracks deeper than                      loosely under a
                                                            one inch are eliminated                      thin layer of soil.

Fixed or Spring                                 Pull implement fast                             Pull implement
Harrow                                              (5-8 mph) over seedbed                     slowly over seedbed
                                                            with teeth down until                            with teeth down to
                                                            clods are broken up                             loosely cover seed
                                                            and cracks deeper than                      under a thin layer of
                                                           one inch are                                          soil. Only pass over
                                                            eliminated                                              the seed one time.

Cultipacker                                        Not recommended                               Not recommended


All Imperial Blends Except Imperial PowerPlant and Pure Attraction


Smoothness Test: All clods and cracks should be eliminated

Firmness Test: Walk out in your seedbed, and look at the depth of your tracks

“Optimum” Tracks barely visible

“Loose” Tracks more than ¼ - ½ inch deep

“Hard” Tracks not visible

Moisture Test: Ball dirt up tightly in hand, and open hand.

“Optimum” Soil ball holds together for a few seconds and then falls apart

“Dry” Soil ball falls apart immediately

“Wet” Soil ball doesn’t fall apart

Goal: Place seeds in good contact with the surface of the soil, and keep them there.

Implement Used
To Smooth and
Firm Plot Before                                                                                         Action After
Seeding                                     Action Before Seeding                             Seeding

Weighted Drag                        Pull implement fast                                   None
                                                  (5-8 mph) over seedbed
                                                  until seedbed smooth.

Drag Harrow                            Pull implement fast                                   None
                                                  (5-8 mph) with teeth
                                                  up over seedbed until
                                                  seedbed smooth.

Cultipacker                             Test for soil moisture.

                                                If soil moisture is optimum,                      Cultipack after
                                                 cultipack to optimum                                seeding
                                                firmness before seeding.

                                                If soil is wet, wait until it                          Cultipack after
                                                dries to optimum first.                               seeding
                                               Then, cultipack to optimum
                                               firmness before seeding.

                                               If soil is dry, you have two options:

                                              1. Wait until soil moisture                           Cultipack after
                                                improves to optimum. Then,                      seeding
                                               cultipack to optimum
                                               firmness before seeding.

                                              2. If you cannot wait for rain,                      Do not cultipack
                                               cultipack to get seedbed as                       or do anything else
                                              smooth as possible, and go                      to the plot after
                                               ahead and broadcast seed.                       seeding.

As you can see, each one of the three implement types has its advantages in certain situations and its disadvantages in others. If I had to pick which of the three would cover the most jobs involved in the planting process, I would have to pick the chain-link drag harrow because you can do so much with one. They’re also pretty inexpensive, available at almost any farm supply store, and can usually be moved around and used even if you don’t have someone to help you. That doesn’t mean that it will do all jobs better than any of the others. In fact, I own all three for just that reason.

If you would like more information on drags, harrows, cultipackers or any other matter related to deer or deer hunting, feel free to call our in-house consultants at (800) 688-3030, ext. 2 or visit www.whitetailinstitute.com.