Calibrating the Seed Drill

John Deere Type B Seed Drill

My John Deere Type B Seed Drill needs to be calibrated so that it dispenses the seeds at a predetermined rate – usually pounds per acre. This drill emits seeds based on volume/size rather than weight.

I learned how to calibrate a seed drill from this video.

Setting the drill on stands so the wheels can spin freely and turn the drill to emit seeds.

The first step is to get the drill off the ground so you can spin the wheels freely. It’s a delicate operation as there aren’t many safe places to lift the drill.

I use a shop lift with a chain around the short axle.

The drill is quite heavy and there aren’t many places to lift or jack without damaging the axle or gears.

I use a jackstand to hold the drill up while I’m working on it. Note the very narrow space for the jack stand to rest without damaging the axle and gears.
A good grease job every time helps insure that my drill be continue to be useful in the future. I invested quite a bit of time in rebuilding it so I want to make sure it lasts and works well for a long time.

Greasing equipment is a nasty job but definitely worth it. This drill sits outside (too big to fit in the barn) so taking a little extra care is worth it.

The drill is fully elevated and ready for calibration.

The purpose of elevating the drill is to allow you to spin the wheels freely and emit seed. It also requires that you lower the discs to the lowest position so the seed can flow freely through the seed tubes.

I collect the seeds in an empty water bottle but since we’re going to be dealing with very small measures, a tare on the bottle is necessary.
Water bottles are mounted on stands (bricks or blocks) to mate closely with the seed tubes and accurately collect all of the emitted seeds.
Closer detail of bottle setup for seed collection.
This lever controls the feed rate for one half of the seed drill. There is another lever on the other end of the drill.
The drill wheel is marked with tape to accurately count wheel revolutions.
A small amount of millet seed in the hopper for calibration measurement.
Seed collection while the wheels are turned.
Weighing collected seeds.

Here are my calculations:

Wheel diameter = 86″ or 7.1666′

Row spacing = 7″ or 0.58333′

Tare weight of bottle = 21g

I desire 55#/acre for each of foxtail millet and hegari.

Hegari is first to calibrate since it will plant last.

48g of seeds (plus 21g of tare) needed in each bottle based on calculations from video above.

Loosen and set seed flow lever to 8 based on very faded instructions on the inside of the seed hopper lid for wheat at 60#/acre as a reasonable starting point.

Turn wheel 20 times and weigh seeds.

The 4 bottles resulted in 51g, 54g, 61g, 67g – so too little and need to open seed flow lever a little bit. Also, the right side feeds more than the left side.

Add 2 notches on the left side and leave the right side alone and will be good enough for millet.

Restart calibration with Foxtail Millet.

The 4 bottles resulted in 52g, 55g, 50g, 45g – again too little and need to open seed flow lever more. Sides appear to be balanced though.

Adjust left side to 8 and right side to 10 and retry.

The 4 bottles resulted in 72g, 62g, 55g, 60g – on average too little but good enough to go with.

Adjustments in the lever increase or decrease the seed feed rate.
Seed drill calibrated and ready to plant!


I measured my acreage at 1.8 acres and used 100# each of foxtail millet and hegari seeds. I planted each separately at the rate of approx 55#/acre so I should have almost exactly run out of seed at the end of my planting for each seed.

But, the hegari ran out early at 80% planted (20% short) and the millet ran long at 80% over.

As I was cleaning up I noticed that I had not cleaned out the hopper and seed feed mechanism well enough. I use compressed air and was blowing out the seed hopper and all kinds of crap came up from the seed feed gears that I did not notice early in the process.

I need to do a better job of cleaning and prep to get a more accurate planting next time.

The New Raised Bed Square Foot Garden

My Original Raised Bed Garden/Square Foot Garden suffered from a lack of sunlight. I had dreams of more and bigger.
So I found a sunny area and started a newer, bigger and more advanced square foot garden.
Lots of detail work went into leveling the boxes as the site is on a slight incline.
It started as 8 4×4 boxes fenced to keep out the critters.
Each “box” has a time controlled valve for drip irrigation with underground supply from my rainwater collection system.
Version 1.0 complete!
But it didn’t take very long before I got greedy and doubled 5 of the 8 boxes. I left 3 alone specifically for tomatoes.
I even put a mini-box on the one on the end!
Each box has a weed liner – they fail after a few years though.
It got a little crowded in there adding the SFG soil to the already fenced garden!
I also added a large rear gate to help remove plant clippings and stalks more easily.
All of the boxes with vining plants have side, roof and cross panels for trellis.
Each box also get’s bunny wire to further protect the plants. We live in the woods and are covered up with deer and various critters that eat my plants.
LOL – I even tried corn a time or two but the SFG soil isn’t deep enough so they crowd and fail to pollinate well. That corn cage is to keep the critters out and support the stalks.
My vining plants – cucumbers & tomatoes – love those extra trellises though!
I have a total of 13 4×4 boxes to work with and each has dedicated drip irrigation so I have lots of options for starting and growing a variety of plants.
But, anytime you have plumbing, you’re going to have leaks!
An early prototype of a dirt garden for corn that reuses the corn cage.
July Garden in Texas
September Garden in Texas
With careful planning and a little luck, I can harvest as late as October.

The Old/Original Raised Bed Garden

I’m a fan of gardening – more specifically, a fan of the results of gardening!

My oldest daughter wanted to learn and I wanted to teach her about gardening.
These results!
We started with a simple 4×8 wooden box filled with good garden soil. I also ran a hose from the house to a simple watering timer so I could use drip irrigation.
I then decided that official Raised Bed Garden (RBG) Mix might be better. I continue using this mis today.
I removed the top portion of garden soil and then mixed in the new RBG components.
Just in time for my youngest to enjoy with me.
RBG recommends cleanly marking the 1 square foot areas.

I installed some rain water collection at the house and then switched from a hose laying on the ground to a buried pipe for the water supply.
Even the little RBG gardens can produce quite a bit of vegetables!
Corn doesn’t do well in an RBG due to the very close spacing required for enough plants.
I stick mostly with tomatoes, cucumbers and occasionally some corn.
The RBG can get very very full!
I found that covering the RBG for winter helped but not much. I no longer do this.
Water pipes underground can break and need repairs. I’m ever watchful for leaks and moist areas on the ground.
I decided to enlarge the garden by adding some more RBG boxes. I started with killing the grass & weeds.
I tried laying the ground cloth down first to help kiil the grass and weeds even more.
Meh, but the dogs just chewed it up over night.
Deer are a problem for my garden so I use an electric cattle fence around my garden.
New RBG boxes built from deck material ready for RBG Mix mixing.
Lot’s of mixing – it’s a bigger job than I ever estimate.
Two new RBG boxes completed with room for 2 more.
I also amend the RBG soil in older boxes when I have extra or it appears they could use some help.
I think I over-bought.
Extra stakes and lattice help RBG gardens a ton. Most plants want to go horizontal rather than vertical and the lattice helps change their minds.
Drip irrigation is also a Must for me. I try to build for 1 emitter per plant.
Even little lattices help in the beginning.
This garden location is not optimal as it has too much shade. I finally learned this but it took several years.
We have snakes in TX and they can sneak up on you. This is a 3′ rattle snake.
I turned one of the RBG boxes sideways and build 2 more smaller RBG boxes at 4×4.
Bunnies started hitting me hard so I began using bunny wire also.
Full RBG Garden!
That RBG garden has been disassembled and all that’s left is the original. It now has wildflowers and butterfly weeds. My new RBG Garden is here.