We often receive questions from growers with older seeders and planters who are looking to match seeds to the planter plates they have on hand. To get a good stand, it is important to use the plates that best suit the size and shape of the seed you have chosen, which will vary for each crop, variety, and seed lot.
Sweet Corn
At Harris Seeds, we record the seed size, shape, and seed count per pound for every lot of sweet corn we receive. We also determine the recommended planter plate numbers for each lot. Sweet corn seed can be round or flat, medium or large, and the plate needed for a specific lot will depend on the combination of these traits. Round corn plates have a round or teardrop shaped cell, where flat corn plates have a rectangular cell. The genetic type of the sweet corn can also determine if the dried kernels are more shrunken or full, which changes how they flow through the plates.
If you own a limited number of planter plates and would like to order seed that you know will fit, call us before you place your order. We will review our current inventory for the varieties you are interested in growing and help you choose the ones that are compatible with the plates you already have. Be sure to have a list of your planter plates nearby when you call.
If you have already ordered your seed and want to be sure you own the plates you’ll need for those seed lots, we are happy to provide plate number recommendations. These recommendations are printed on the label of sweet corn packages of 10M or larger, or you can call or email us to request the information. Please be sure to include the variety and lot number you would like recommendations for.
As an example of the type of information we can supply, our current lot 41104 of Sweet Corn Rosie F1 has a Large Flat (LF) seed with 3,231 seeds per lb. and the recommended plates for John Deere planters are B17 and B10 and for International Harvester planters are C17 or C697.
Other Vegetables and Sunflowers
Many growers are successful in planting other vegetable and sunflower seeds with their plate planters, especially pumpkins, squash, and gourds. Unfortunately, we do not have the same detailed information on record for these crops as we do sweet corn and cannot provide exact plate number recommendations.
Lincoln Ag Products is a great resource for vegetable and sunflower plate information. Based on their experiences and grower feedback, find some of their plate suggestions below or visit their website for more specifics. Always test above ground before planting in the field.
• Beans: Large Flat Corn Plates
• Collards, Okra: Large Single Drop Sorghum Plates
• Cucumber, Watermelon: Small Sunflower Plates
• Peas: Medium to Small Round Corn Plates
• Pumpkin, Squash: most growers prefer to cut their own plates, see steps below
• Sunflowers: purchase plates specific to sunflower seeds
Another way to achieve your preferred planting rates and seed flow is to cut your own plates to suit your needs. Lincoln Ag Products sells blank plates and offers suggestions for cell spacing. Trial and error will help you find or create plates that are just right for your operation and chosen crops.
How to Cut Your Own Planter Plate
- Select one of the largest seeds in your sample, lay it on the flat flange part of the plate and trace it.
- Cut out the rough shape using a Dremel tool or hand file. Be sure to cut small at first and test the fit of the seed as you go.
- Your goal is to finish with a cell that fits your intended seed but does not allow another seed or partial seed within the cell; ideally a 1/64” clearance around the seed.
- After cutting one cell, test the plate with some seed in the hopper for a few rotations above ground. If the seeds move smoothly, proceed with cutting additional cells in the plate to achieve your preferred spacing.
Purchasing Planter Plates
Harris Seeds proudly sells Jang and Earthway seeders, plates, and seed rollers. If you have questions about these products, please contact us.
If you are looking to purchase plates for a John Deere, International Harvester, or other planter manufacturer, please contact Lincoln Ag Products. They manufacture planter plates and have great resources available to help you determine what size plates you might need. You can also send them a sample of 10-20 seeds and they will test it in different plates to offer a recommendation.
Tips for Using Plate Planters
A commonly overlooked setting on planters is the down pressure springs and seeding depth. Be sure that the seeding depth is set for your soil moisture and conditions to prevent planting the seed too deep. Deeply planted seeds will germinate slowly or not at all. Trial and error will help you know your soil conditions and learn the ideal settings for your planter.
Seed spacing depends on the number of cells on the plate and the sprocket settings. A 16-cell plate will plant 1/3 less than a 24-cell plate. Depending on your planting goals, sometimes it is easier to change row spacing by switching planter plates instead of adjusting sprocket settings. Refer to your planter’s Operators Manual for sprocket settings specific to the make and model.
Questions about seed planter plates for specific sweet corn varieties? Send us a message directly via our online contact form.
Questions about any other vegetable seed varieties? Please contact Lincoln Ag Products.
