How this calculator gets from an acre rate to a bag weight
Every published seeding recommendation is written as pounds of Pure Live Seed (PLS) per acre. Your bag is not pure live seed. Somewhere inside it is inert material — chaff, dust, coating, grit, the occasional weed seed — and some share of the real seed will never sprout. A recommendation and a bag weight are therefore two different quantities, and converting one into the other is the entire job of this page:
Bag lbs = method rate (drilled or broadcast) × acres ÷ (purity % × germination %)
Three things drive that answer: how big the plot honestly is, whether you are drilling or broadcasting, and what the analysis tag on the bag says. All three are easy to get wrong in the same direction — toward buying and spreading more seed than the ground can use.
Measuring an irregular plot without flattering it
Almost no food plot is a rectangle. It is a logging deck with a hooked tail, a powerline strip that narrows toward one end, an old field with a boggy corner and a stump row down one side. The temptation is to pace the longest length, pace the widest width, multiply, and call the result an acre.
That method cannot help but overestimate. Multiplying the extreme dimensions describes the smallest rectangle that would contain the plot, so every square foot of timber, ditch and turnaround caught inside that box gets counted as ground you intend to plant. On a genuinely ragged shape the difference is large, and it is invisible, because nothing about the resulting number looks wrong.
Pacing stacks a second error on top of the first. A stride you calibrated walking a mown yard shortens in standing cover, on a side slope, and in mud, so the same count of paces across worse footing quietly reports more distance than the ground actually holds. If you are going to pace, calibrate the same day you measure: walk a marked 200-foot run, count your paces, and divide to get your real stride length. A tape, a wheel or a phone's GPS area tool beats pacing outright.
The honest approach is to break the plot into shapes you can measure and add them together. Rectangles are length times width; triangles are half the base times the height; a curving edge can be handled as a series of narrow strips, each measured at its own width. Then subtract the ground you will not plant — the stump row, the wet hole that never dries, the shaded northern margin where seedlings never establish. If you measured in square feet or square yards, enter those units directly; the calculator divides by 43,560 or 4,840 for you and prints the acreage it used. Check that acreage figure before you look at the pounds, because it is the input carrying the most uncertainty.
Per acre, per bag, and the partial-acre trap
Rates are published per acre. Seed is sold in bags. Most food plots are fractions of an acre, and that mismatch is where the arithmetic reliably comes apart.
The failure mode is not subtle. A half-acre plot receives a full acre's bag because the bag was open, was already in the buggy, and would not keep until next season. Take ladino clover at this page's broadcast rate of 8 lbs PLS per acre. Empty an acre's worth onto half an acre and you have applied 16 lbs per acre — double the broadcast rate and quadruple the 4-lb drilled rate. Nobody decided to do that; it happened because the bag became the unit of measurement instead of the acre.
Scaling errors also travel in a straight line. Overstate your plot by a fifth and you buy a fifth too much seed, then spread all of it on the smaller real acreage — so a fifth too much area becomes a fifth too heavy a stand. Weigh out what the calculator asks for, spread that, and keep the remainder dry and labeled for the thin spots you will find in three weeks.
Worked example: half an acre of ladino clover
Run the page's own defaults. White clover, plot size 0.5 acres, broadcast, a tag reading 95% purity and 85% germination.
- Pure live seed = 0.95 × 0.85 = 0.8075, which the result panel rounds to 81%.
- Ladino clover broadcasts at 8 lbs PLS/acre here, so half an acre calls for 4 lbs of pure live seed.
- 4 ÷ 0.8075 = 5.0 lbs of bag seed.
Switch the method to drilled and the base rate drops to 4 lbs PLS/acre: 2 lbs of pure live seed, 2 ÷ 0.8075 = 2.5 lbs out of the bag. Identical plot, identical tag, half the seed. That difference is what seed-to-soil contact is worth in money.
Why broadcast rates run higher than drilled rates
A drill sets seed at a chosen depth in a slot it has just opened and closes the slot behind it. Broadcast seed lands where it lands: on residue, in a crack, on baked crust, or out in the open where songbirds, turkeys, ants and mice work it over before the first rain arrives. A meaningful share never touches moist soil at all, and the published rate increase is compensation for that share.
The compensation is species-specific rather than one universal multiplier, and this page's own paired numbers show the spread. Alfalfa goes 15 drilled to 20 broadcast, and the cereal grains 100 to about 130 — both roughly a third more. Ladino clover doubles from 4 to 8, brassicas from 5 to 10, soybeans from 50 to 100. Small, light seed that must be placed shallow suffers most from being thrown; heavier seed planted deeper suffers least. The calculator stores each species' published broadcast figure and only falls back to a generic 1.5× when you type a custom rate it has no published pair for.
Cultipacking closes much of that gap for very little money. Rolling a broadcast plot presses loose seed into firm contact with moist soil and gives it a chance the surface never would. If you do one thing beyond spreading, drive something heavy over small-seeded plots afterward.
Pure live seed, and why the tag beats the label
Purity is the proportion of the bag that is the species you paid for. Germination is the proportion of that seed which will actually grow. Multiply them and you have pure live seed. Two bags of the same brand, same artwork and same net weight can hold noticeably different amounts of living seed, and the only place that shows is the analysis tag attached to the bag — never the front of the sack.
Coated seed sharpens the point. Coating and inoculant add weight that is not seed, and the tag accounts for that in the purity figure, which is precisely why comparing prices by tag rather than by bag weight is the only defensible way to shop. A cheap bag with a low PLS is not cheap.
This is the same adjustment our drill calibration calculator makes from the opposite direction. There you divide a PLS target by the tag figure to find the bulk rate to set the meter for; here you divide a PLS recommendation by the tag figure to find the pounds to buy. One piece of arithmetic, two ends of the same job.
Over-seeding is the common mistake, and the expensive one
Thin stands look like failure and heavy stands look like insurance, so people round up — an extra scoop, the tail of the bag, a second pass for good measure. It is the most consistently counterproductive habit in food plotting.
Crowded seedlings compete against each other for the same water, light and nitrogen. Clover sown heavily comes up spindly and shallow-rooted, then browns off in the first dry stretch. Brassicas set small roots when they are thick, because bulb size is a function of the room each plant is given, and the bulb is much of the point. Heavy cereal stands lodge and shade out the legume seeded with them. None of this is visible at emergence, when a thick plot looks like a success.
It is also money spent twice: once at the counter, and again in the stand you did not get. A drilled clover recommendation of 4 lbs per acre leaves no room for generosity — an extra 2 lbs is a 50% error on that rate. The mistakes are asymmetric, too. A thin stand can be over-seeded next season, or frost-seeded into, or fertilized into filling out. Nothing thins a crowded stand except time and weather.
Food plot seeding rates — Southeast (MSU) profile, planted alone
| Species | Drilled (lb PLS/ac) | Broadcast | Plant | Depth |
|---|---|---|---|---|
| White (ladino) clover | 4 | 8 | Spring or fall | ≤¼" |
| Red clover | 10 | 15 | Fall | ≤¼" |
| Crimson clover | 15 | 25 | Late summer | ≤¼" |
| Brassicas | 5 | 10 | Mid–late summer | ¼" |
| Chicory | 5 | 10 | Spring or fall | ¼" |
| Winter wheat | 100 | ~130 | Fall | ~½–1" |
| Cereal rye | 100 | ~130 | Fall | ~½–1" |
| Oats | 90 | ~120 | Spring or fall | ~½–1" |
| Soybeans (commercial) | 50 | 100 | Late spring | 1–1.5" |
| Austrian winter peas | 30 | 50 | Fall | 1–2" |
Rates follow Mississippi State's Southeast food-plot guide; your state's extension recommendations may differ — check locally. Clovers and other small seeds should never go deeper than about ¼".
What this calculator cannot tell you
It turns a rate into a weight. It knows nothing whatever about your dirt, your calendar, or your deer, and those decide whether the plot works.
Soil test and pH. Seed is the cheap part. A test through your state or county extension office — fees are modest and vary by state — tells you the lime and fertilizer the ground actually needs. Clovers and brassicas are among the least tolerant of acidity, and on sour, unfertilized soil a perfectly calculated seeding rate still produces a disappointing plot. Lime reacts slowly, over months rather than weeks, so a test taken the season before planting is worth considerably more than one taken the week of.
Timing. Planting windows are regional and this page has no idea where you are. Sow too early and the plot matures and is grazed off before you need it; sow too late and there is not enough warmth left for establishment before dormancy. Your state extension service publishes planting-date windows by species and region, and hitting the window matters more than fine-tuning the poundage.
Browse pressure. A small plot in a place with high deer density can be eaten to bare soil before it ever establishes, and no seeding rate fixes that. What fixes it is more acreage, temporary fencing until the stand is up, or species that tolerate grazing. An exclusion cage — a few feet of wire in the middle of the plot — is the cheapest diagnostic tool you own, because it tells you at a glance whether the plot failed to grow or grew and was consumed.
Rainfall, weeds and seedbed. Small seed broadcast onto a cloddy, trashy surface in a dry spell fails at any rate. Nothing in this arithmetic accounts for moisture, competition from existing vegetation, or how well the ground was worked.
Frequently asked questions
How much seed for a ¼-acre plot? Quarter the per-acre broadcast rate: white clover ≈ 2 lbs; brassicas ≈ 2.5 lbs; winter wheat ≈ 32.5 lbs — all before the PLS adjustment, which raises each figure.
When should I plant brassicas for deer? Late summer in most of their range, early enough that leaves and bulbs are developed before hard frost sweetens them. Get the specific window from your extension service.
Can I just throw and grow? Broadcasting alone works best with tiny seed on exposed soil ahead of a rain. Expect thinner, patchier stands — that expectation is exactly what the higher broadcast rate is paying for.
Should I buy extra? A little, for edges and thin spots. Not a second bag, and not a second pass.