What Are Pelleted Seeds? (3 Things To Know)

Some small seeds are difficult to plant – carrots, lettuce, and onions come to mind. Pelleted seeds make it much easier to sow the smallest seeds.

So, what are pelleted seeds? Pelleted seeds are ordinary seeds covered in a coating to give them a “pellet” appearance. The coating on pelleted seeds is an inert material, such as clay. Pelleted seeds are larger and heavier than ordinary seeds, so they are less likely to get lost or blow away in the wind. Some pelleted seeds are also treated – for example, with fungicides to protect against diseases in the soil.

Of course, pelleted seeds have both advantages and disadvantages. For example, pelleted seeds are a bit more expensive than ordinary seeds.

In this article, we’ll take a closer look at pelleted seeds and why you might want to use them. We’ll also get into buying, planting, and germinating pelleted seeds.

Let’s get started.

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What Are Pelleted Seeds?

Pelleted seeds start off as ordinary seeds, but they are covered with a layer of inert material (usually a clay mixture).

This coating makes the seeds larger, which gives several advantages over ordinary seeds (more detail on this later).

Pelleted lettuce seeds (left) are larger and easier to work with than raw lettuce seeds (right).
Photo courtesy of Dwight Sipler via Wikimedia Commons https://commons.wikimedia.org/wiki/File:Lettuce_seeds_(464344612).jpg

Pelleted seeds are often shipped in vials within seed packets. These vials protect the pellets from being crushed during shipping.

Pelleted seeds often come in the shape of round “pearls”, although you may also find longer, thinner “cylinder” versions of pelleted seeds.

onion seeds — Pelleted seeds are convenient for small seeds, such as carrot, lettuce, and onion.

Some pellets may even contain multiple seeds, although this is more likely for seeds with a poor germination rate.

According to Incotec, pelleted seeds either split open or disintegrate on contact with water. The seed inside can then absorb water and begin the germination process.

What Are Pelleted Seeds Coated With?

Pelleted seeds are coated with an inert substance to make them larger and give them a uniform size and shape. According to INSR, this inert substance is often a clay or talc mixture, which may also contain adhesives (glue).

An inert substance is one that will not have a negative effect on the seeds that it comes in contact with.

Pelleted seeds may also be treated with various active ingredients, such as:

Fungicide – this will protect the seed from mold in the soil, which is especially useful when direct sowing seeds outdoors (which is necessary for carrots and other seeds that are difficult to transplant).
Insecticide – this is less common, but it may be necessary in areas where certain insect pests are a serious threat to the seeds before or after they germinate.
Nitrogen Fixing Bacteria – according to the University of Georgia Extension, the seeds of legumes (peas, beans, etc.) are sometimes treated with nitrogen fixing bacteria, which help to convert nitrogen in the air into nitrogen compounds that plants can use for growth.

pea plant — Pea seeds and other legumes are sometimes treated with nitrogen fixing bacteria.

You can learn more about seed treatments in this article from Wikipedia.

Are Pelleted Seeds Organic?

Not all pelleted seeds are organic. As mentioned above, some are treated with artificial chemicals, such as fungicide or insecticide.

However, some seed companies do offer organic pelleted seeds. For example, West Coast Seeds has organic pelleted seeds available.

Untreated pelleted seeds are not treated with any biological or chemical method. Untreated seeds may be fine for starting seeds indoors in sterile potting soil.

However, seed treatments may be necessary for direct sowing seeds outdoors, especially if diseases or insects have been a problem in the past.

Why Use Pelleted Seeds?

Pelleted seeds have several advantages over ordinary uncoated seeds:

Easier handling – have you ever had a hard time picking up small seeds, such as carrot, lettuce, or onion seeds? Pelleted seeds are much easier to pick up, so you won’t have the problem of not being able to grab your seeds.
Heavier – according to Seed Dynamics, pelleted seeds are 10 to 40 times heavier than ordinary seeds. This means that they won’t blow away in the wind (or if you breathe on them!)
Larger – pelleted seeds are larger than ordinary seeds, so they are less likely to get lost if you drop them.
Better Spacing – pelleted seeds are easier to plant at the proper spacing in a row. This gives each plant enough room to grow and prevents tangled weeds and competition among plants.
Less Seed Thinning – if you plant too many small seeds close together, you will need to thin some of them. Pelleted seed prevents this problem, which reduces wasted seeds.
Less Machine Jamming – if you use a mechanical seeder to help with planting, pelleted seeds are much less likely to jam in the machine.

Pelleted seeds are less likely to jam in a seeding machine.

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Are Pelleted Seeds Better?

Pelleted seeds are not necessarily better than ordinary seeds in all cases. Each type of seed has its own advantages and uses.

It is true that pelleted seeds have all of the advantages listed above. However, there are also some disadvantages of pelleted seeds:

More Expensive – on a per-seed basis, pelleted seeds are more expensive than ordinary seeds. This is because the pelleting material, treatments, equipment, and time involved in the pelleting process all cost money. Treatments (such as fungicide, insecticide, nitrogen fixing bacteria) will also make seeds more expensive.
Too Round – some pelleted seeds may be too round, to the point where they roll around and drive you crazy trying to herd them into place.
More Volume – since pelleted seeds are so much larger, they take up more space. This won’t be a huge problem if you don’t have a large garden, but it could be a consideration if you are growing at scale.
Shorter Shelf Life – pelleted seeds do not last as long as ordinary seeds. Sometimes a chemical treatment reduces the lifespan of the seed, but the inert coating may also reduce their viability.

How Long Do Pelleted Seeds Last?

Pelleted seeds do not last as long as ordinary seeds. The pelleting process reduces their shelf life.

Some of the fungicide or insecticide treatments may also affect the longevity of seeds. Johnny’s Selected Seeds recommends using pelleted seeds within one year.

How To Plant Pelleted Seeds

You can plant pelleted seeds in a similar way to ordinary seeds. There are a few ways to plant pelleted seeds:

By Hand – take each seed pellet and place it in a cell (if using a seed tray), pot, or hole (if direct sowing outdoors).
By Mechanical Seeder – you can use a machine that automatically plants seeds at the correct spacing, such as this push seeder from Johnny’s Selected Seeds.
By Vacuum Seeder – you can use a vacuum seeder setup to seed an entire tray in one go. The suction draws one seed into each hole (you may need to bump the tray until the seeds move into place). You can find a vacuum seeder from Johnny’s Selected Seeds.

How To Germinate Pelleted Seeds

After planting pelleted seeds, it is important to keep the soil moist to ensure proper germination. The coating on pelleted seeds will absorb some water, causing them to split open or disintegrate.

The water can then get to the seed so that it can germinate. It is important that you not allow the soil to dry out.

Otherwise, the seed coating may draw moisture away from the seed. If a seed dries out during germination, it may not sprout.

If your pelleted seeds are not germinating:

Check Soil Temperature – soil temperature is one of the most important factors for seed germination. Extreme high or low temperatures can both lower germination rates or increase the time to seed germination. These tables from the University of California will help you to determine the ideal soil temperature, depending on the crop.
Check Seed Age – remember that pelleted seeds do not last as long as ordinary seeds. If you try to use pelleted seeds from last year (or earlier), they may not sprout at all, or they may have reduced germination rates.
Check Soil Moisture – seeds need moist soil and humidity in order to germinate. However, keeping soil too soggy will deny them the air they need to germinate and grow properly.