Buying Microgreen Seeds in Bulk: Cost Savings, Storage & What We Actually Buy

July 12, 2024

After growing microgreens since 2018, one question we get asked constantly is whether it's worth buying seeds in bulk or just grabbing a small bag at a time. The short answer is yes, bulk almost always wins on cost per tray. But there's more to the decision than just price, especially if you're a beginner, growing a wide variety of crops, or working with limited storage space.

This blog walks through the real cost-per-tray math, the pros and cons of bulk seed buying, the bag sizes we actually use ourselves, and how to store seeds so they stay viable. If you're brand new to growing, our Beginner's Guide to Growing Microgreens PDF is a great place to start before you commit to a 25-pound bag of seed.

Quick Answer: Is Buying Microgreen Seeds in Bulk Worth It?

Yes, buying microgreen seeds in bulk is almost always more cost-effective per tray, often dropping the cost per 1020 tray by 80 to 90 percent compared to small 1-ounce bags. Bulk also gives you batch consistency and a ready supply. The trade-offs are higher upfront cost, storage space, and the risk of being stuck with a variety you may not love. For most regular growers, the 1-pound to 5-pound range hits the sweet spot. For commercial growers, 25-pound bags make sense for staple crops like broccoli, radish, sunflower, and pea.

How Much Cheaper Are Bulk Microgreen Seeds Per Tray?

25 grams of mammoth red rock cabbage seed on a 10x20 tray growing on stainless steel reusable microgreen grow medium from On The Grow

The cost savings from bulk seed buying are dramatic. To show what we mean, here's a real-world example using Broccoli Waltham 29 microgreen seeds from True Leaf Market (one of our favorite suppliers since 2018) at 25 grams of seed per 1020 tray, which is what we recommend for most brassicas.

Broccoli Waltham 29 Cost Per 1020 Tray (Current Pricing)

Bag Size	Grams	Trays Covered (at 25g)	Approximate Cost per Tray
1 oz	~28 g	~1	$5+
4 oz	~113 g	~4.5	$1.50 to $2
1 lb	~454 g	~18	$0.75 to $1
5 lb	~2,268 g	~90	$0.50 to $0.60
25 lb	~11,340 g	~453	$0.35 to $0.45

Pricing fluctuates throughout the year. Always check current pricing directly on True Leaf Market before purchasing. The link above is our affiliate link, which earns us a small commission at no additional cost to you.

The pattern is the same across every variety we've ever tested. A 1-ounce bag of broccoli might cost you over $5 per tray. A 25-pound bag drops that to under $0.45 per tray. That's a roughly 92 percent cost reduction.

The same math holds for radish, kale, mustard, cabbage, salad mixes, and any other small-seeded brassica. For larger seeds like sunflower and pea where you're using 100 to 150 grams per tray instead of 25 grams, the bulk savings are still significant, just spread across fewer trays per bag.

How to Calculate Cost Per Tray for Any Seed

If you want to figure out the cost per tray for any seed variety, the formula is simple:

(Total bag price ÷ total grams in bag) × grams of seed used per tray = cost per tray

For example, a 1-pound bag (454 grams) of broccoli at $14 used at 25 grams per tray:

($14 ÷ 454) × 25 = $0.77 per tray

Once you know your seeding density per tray (covered in our Free Tray-Specific Seeding Guide and our Free Microgreen Seeding Guide), you can do this math on any seed listing in seconds.

The Bag Sizes We Actually Buy

For our own home growing and content creation, we lean toward the 1-pound to 5-pound range on most varieties. Here's our typical breakdown:

1 to 5 pounds: Broccoli, radish (Rambo, Daikon, China Rose), kale, cabbage, kohlrabi, mustard, salad mixes. These are our staples and we know we'll use them.
5 pounds and up: Pea and sunflower. These crops use 100 to 150 grams per tray, so a 1-pound bag only covers 3 to 5 trays.
4 ounces or less: Anything we're testing or experimenting with. Specialty varieties, mucilaginous seeds like basil, or any crop we haven't decided is a staple yet.

If we were running a commercial operation again with steady restaurant accounts, 25-pound bags would absolutely make sense for the core crop list. The savings compound fast when you're running 20 to 50 trays a week.

What Beginners Should Buy First

If you're just starting out, do not jump straight to a 25-pound bag of anything. We see this mistake all the time. Here's what we recommend instead:

Start with 1-ounce or 4-ounce bags of 3 to 5 different varieties so you can test what you and your family actually like to eat.
Once you've identified your 1 or 2 favorites, scale up to a 1-pound bag of those.
Only move to 5-pound or 25-pound bags once you've successfully grown the same variety 5 to 10 times and know it's a long-term staple in your rotation.

If you're not sure where to start, broccoli is the perfect first crop. It germinates fast, is beginner-friendly, and has been studied extensively for its sulforaphane content. Our complete broccoli microgreens guide walks through the full process from seed to harvest.

Consistency and Quality Control

Sunflower microgreens with seed hulls still attached growing in a 10x20 tray on coco coir from On The Grow

One advantage of bulk buying that doesn't get talked about enough is batch consistency. When you buy a single large bag, every seed you plant for the next 3 to 6 months is from the same lot. That means similar germination rates, similar days to harvest, and predictable yields. For commercial growers selling to restaurants, this consistency is huge.

To give you an example, we once had a batch of sunflower microgreen seeds that germinated perfectly and quickly on every tray. That continued through the entire bag. The next bag we bought, planted using the exact same method, took noticeably longer to germinate and added a day or two to our days-till-harvest timing. If we had been delivering to a customer on a fixed schedule, that change would have caused real problems.

Now imagine that same variability happening across 10 small bags from 10 different lots instead of 1 big bag. The inconsistency multiplies fast.

Storage and Long-Term Seed Viability

Bulk seeds only save you money if you can keep them viable. Stored properly, most microgreen seeds last 2 to 5 years with strong germination rates. Stored poorly, you can lose germination in under a year.

What proper seed storage looks like:

Cool: Ideally below 70°F. A basement, cellar, climate-controlled garage, or a dedicated seed fridge all work. Avoid garages or sheds with big temperature swings.
Dry: Humidity is the enemy. Use airtight containers (food-grade buckets, mason jars, or vacuum-sealed bags) and toss in a food-safe desiccant pack if you're in a humid climate.
Dark: Light degrades seed viability over time. Store containers in a closed cabinet, pantry, or opaque bin.
Labeled: Always write the variety and purchase date on every container. We use a FIFO (first in, first out) system so older seed gets used first.

If you're growing on a reusable silicone grow medium or any other reusable system, your per-tray cost is already dramatically lower than soil or coco coir. Pairing bulk seed buying with reusable mediums is one of the biggest cost reducers for growers running a lot of trays.

Convenience and Reduced Environmental Impact

Bulk buying also cuts down on order frequency, shipping costs, and packaging waste. Instead of receiving a dozen small mylar pouches throughout the year, you receive one large resealable bag. Less cardboard, less plastic, fewer trips for the delivery driver. If you're growing on reusables and buying seeds in bulk, you've cut packaging waste at both ends of the operation.

Avoiding Bird Seed for Growing Microgreens

This warning shows up in almost every microgreen-buying conversation, and it deserves repeating. Do not use bird seed to grow microgreens. Bird seed is not produced or handled to the same food-safety standards as human-grade seed. It can be contaminated with bacteria, fungal spores, or other pathogens that pose real food safety risks when you're eating the resulting microgreens raw. Some bird seed is also treated with chemical coatings that are not safe for human consumption.

Always use seeds that are specifically labeled and sold for sprouting or microgreens production. Reputable suppliers like True Leaf Market test their seed lots for pathogens like E. coli and Salmonella before selling, which is the standard you want for anything you'll eat raw. For more on this, see our microgreens seed quality and food safety guide.

Disadvantages of Buying Microgreen Seeds in Bulk

Various pea microgreen seeds stored in glass jars for long-term seed storage from On The Grow

Bulk buying is not the right move for everyone. Here are the legitimate downsides to weigh before you commit.

Storage Challenges

Space requirements: A 25-pound bag of seed is bigger than most people expect. If you live in a small apartment or have limited pantry space, bulk storage can become a problem fast.
Conditions: Cool, dry, and dark storage isn't always easy to achieve. Hot garages, humid basements, or kitchens next to ovens are not great seed storage locations.
Pest control: Large bags of seed can attract rodents and pantry pests if not stored in airtight containers.

Seed Viability Over Time

Shelf life: Even stored perfectly, seeds lose viability over the years. A 25-pound bag that takes you 4 years to work through will have noticeably lower germination at the end than the beginning.
Decreased germination rates: Older seed can germinate unevenly, which throws off your timing and tray-to-tray consistency. Older seed can also be more prone to mold if it's lost vigor.

Upfront Cost

Initial investment: A 25-pound bag of organic radish or salad mix can run $400 to $600+. That's a big upfront hit for someone just starting out.
Cash flow: For commercial growers, tying up capital in seed inventory can pull money away from other parts of the business (lights, racks, marketing, packaging).

Batch Quality Risk

If the bag is bad, the whole bag is bad: A bulk bag with low germination or contamination affects every tray you grow from it. Smaller bags from different lots spread that risk.
Supplier reliability matters more: This is one reason we've stuck with True Leaf Market since 2018. Their customer service team has consistently stood behind their seed quality when we've had occasional issues, and they test for pathogens before selling.

Variety Limitations

Less room for experimenting: If you've got 25 pounds of one variety to use up, it's hard to justify trying something new.
Market or preference shifts: If your restaurant accounts change orders or your personal taste shifts, a 25-pound bag of a variety you're no longer growing becomes dead inventory.

Inventory Management

Tracking matters: Once you've got multiple bulk bags of different varieties, you need a real labeling and rotation system. FIFO (first in, first out) is the standard.
Decanting: Most growers transfer bulk seed into smaller airtight containers for daily use, which adds a step but extends viability.

Frequently Asked Questions

How long do microgreen seeds last in storage?

Most microgreen seeds stored in cool, dry, dark, airtight conditions stay viable for 2 to 5 years. Brassicas like broccoli, radish, kale, and cabbage tend to be on the longer end. Sunflower and pea seeds have shorter viable windows and are best used within 1 to 2 years for peak germination. Always test a small sample if you suspect your seed has aged out.

What size bag of microgreen seeds should a beginner buy?

Start with 1-ounce to 4-ounce bags of 3 to 5 different varieties so you can test what you actually like before scaling up. Once you've found your favorites and grown them successfully a handful of times, move to 1-pound bags. Skip the 25-pound bags until you're sure you'll use them within the seed's viable window.

Where do you buy microgreen seeds?

We buy almost all of our seeds from True Leaf Market and have since 2018. They test their seed for pathogens like E. coli and Salmonella, carry a wide variety of organic and conventional options, sell in everything from 1-ounce packets to 25-pound bags, and have stood behind their product when we've had occasional batch issues. The link is our affiliate link, which earns us a small commission at no extra cost to you.

Is it cheaper to buy organic or conventional microgreen seeds in bulk?

Conventional non-GMO seeds are almost always cheaper per pound than USDA Certified Organic seeds, sometimes by a factor of 2 or 3. For home growers, conventional non-GMO seed is perfectly fine. If you're selling commercially and your customers expect organic, the organic premium is worth it. For our own home growing we use both, depending on the variety and what's available.

Can you freeze microgreen seeds to extend shelf life?

You can, but it has to be done right. Seeds must be fully dry before freezing (any moisture will cause ice crystal damage), stored in airtight, freezer-safe containers, and brought back to room temperature inside the sealed container before opening (to prevent condensation). For most home growers, cool dry storage at room temperature is sufficient and simpler.

How much seed do I need per tray?

It varies by crop. Most brassicas (broccoli, radish, kale, cabbage, mustard) use about 25 grams per 10x20 tray. Larger seeds like sunflower and pea use 100 to 150 grams per 10x20 tray. Our Free Tray-Specific Microgreen Seeding Guide PDF breaks down exact seeding rates by crop and tray size.

Final Thoughts

The cost savings from buying microgreen seeds in bulk are real and significant. For most regular growers, the 1-pound to 5-pound range gives you the best balance of savings, freshness, and flexibility. Commercial growers running a steady crop list will see the math really work in favor of 25-pound bags on staple crops.

That said, do not let the savings push you into buying more than you can realistically use within the seed's viable window, or into committing to a variety you haven't actually tested in your own grow space yet. For our own setup, we're firmly on Team Bulk Seed, but we got there by starting small, dialing in our staples, and scaling up the bag sizes only on the crops we knew we'd use.

For more on seed quality, food safety, and what to look for when sourcing microgreen seeds, see our microgreens seed quality and food safety guide. And if you want a deeper dive into seeding rates, growing methods, and the systems we use, the Microgreen Masterclass covers everything we've learned in 7+ years of growing.

Happy growing!

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Published: July 2024
Updated: May 25, 2026