Broccoli Table of Contents

1. History
2. Germination
   • Starting Indoors
   • Starting Outdoors
3. Transplanting Outdoors
4. Sun, Soil & Water
5. Companion Plants
6. Edible Landscape & Containers
7. Pests & Diseases
8. Harvesting
9. Saving Seeds
10. Additional Resources

Broccoli History

Origins of Broccoli

Broccoli (Brassica oleracea), has been on quite a journey in its 2,000 year history. Broccoli’s origins can be traced back to the wild leafy cole crops that grew along the coast of the northern Mediterranean. Careful breeding of these wild plants starting in around the 6th century BCE, has resulted in the wide range of brassicas that we enjoy today (cauliflower, most kale, most cabbage varieties, collards, kohlrabi, and Brussels sprouts are all examples of veggies bred from the same species as broccoli but with different shapes and uses).

In Italian, “broccoli” means “the flowering crest of a cabbage.” The Roman natural history writer Pliny the Elder (AD 23-79) wrote about a vegetable matching the description of broccoli, so it’s believed that broccoli was widely used by the Romans during his lifetime. Over the next two millennia, broccoli largely stayed in what is now modern-day Italy. The first known historical mention of broccoli outside of Italy was in France in 1560.

Broccoli’s journey to America is an interesting one. Thomas Jefferson, an avid gardener who experimented with a wide variety of plants at his Monticello estate, might be the first American to have ever grown broccoli on American soil. He mentioned growing broccoli and its close relative, cauliflower, on May 27, 1767.

Broccoli would not gain commercial popularity in the United States until waves of Italian immigrants (for whom broccoli was a well-known vegetable) began arriving in the early 1900s. The D’Arrigo brothers, Stephano and Andrea, arrived in the US from Messina, Italy, and their new produce company planted broccoli in San Jose, California in 1922. The brothers marketed broccoli via a new technology called “radio” to cities throughout the northeast where most of the Italian immigrants in the US were concentrated. From there, the broccoli business flourished and the plant became a staple vegetable in the American diet.

Food As Medicine

As Hippocrates said, “Let food be thy medicine and medicine be thy food.” Every fruit and vegetable has numerous health benefits, but broccoli is especially interesting…

Broccoli’s anti-cancer properties have been well-established by modern science. Over 600 peer-reviewed studies have shown that the phytochemical “sulforaphane” found in broccoli and other brassicas, is perhaps the most potent anti-cancer compound on earth. The compound can’t be stabilized and turned into a pill, it can only come from eating the plants. Interestingly, sulforaphane levels are much higher in broccoli sprouts than the mature plant.

Johns Hopkins University tried to patent the compound, but was ultimately unsuccessful in its lawsuits against commercial sprout growers and was disallowed from claiming ownership of a naturally-occurring compound that was already in existence.

Want to maximize your sulforaphane consumption? Broccoli sprouts contain the highest concentrations of sulforaphane. However, eating raw, steamed, stir fried or baked broccoli is fine too. Boiling broccoli causes the degradation and loss of sulforaphane, so avoid boiling your broccoli before eating it.

The Journey Continues…With You

From Pliny the Elder to Thomas Jefferson to your garden, broccoli is an cancer-fighting powerhouse with a well-traveled history. Enjoy its unique health benefits, its many wonderful culinary uses, and share its seeds with other people so its grow journey can continue!

Ready to start your broccoli seeds? Read on…

Seed Germination

There are two basic methods you can use to germinate your broccoli seeds:

1. Germinate indoors: A little more time-consuming (you have to keep track of watering your seedlings & making sure they are getting enough light);
2. Germinate outdoors via direct sowing into your soil: Very easy. The less time-consuming approach, but your germination rates might be lower than they would be in a controlled indoor environment and you may incur losses from weather or pests. You’re likely to use more seeds direct sowing outdoors than you would germinating indoors.

Neither of these approaches are “right or wrong,” so use whichever method is best for you given the amount of time you have to commit (if growing indoors, a few minutes each day), your level of gardening experience and the resources available to you.

Based on the approach you decide to take, read the next sections about starting your seeds indoors or outdoors.

Starting your Broccoli seeds indoors

Note: All of the indoor seed starting products and supplies referenced in this guide can be purchased via the Seed Starting section of our curated Organic Gardening Supply Store.

1. When to start your seeds

Broccoli thrives in cool/mild temperatures. The best harvests are: 1) in late spring through early summer, and 2) in fall-winter (depending on your climate zone). We prefer fall and winter harvests since there is little risk of the weather warming too quickly and cool temperatures sweeten the florets. Broccoli can grow in mid-summer in cooler climate zones, but it doesn’t grow well in summer in warmer climate zones.

• For Spring & Summer Harvests – Find your last frost date here. You can start your broccoli seeds indoors six to eight weeks before your last frost date for spring-summer harvests. In areas where springs warm up quickly we recommend starting even earlier and using winter protection methods.
• For Fall Harvests – For ideal fall-winter harvests, start your broccoli seeds indoors 12 to 14 weeks before your first frost date, and transplant the broccoli seedlings outdoors once they are about four weeks old.

2. What to plant them in:

POTS: We recommend sowing your broccoli seeds 1/4 inch deep in your choice of:

• reusable plastic plant cells and a solid plastic bottom tray (Bootstrap farmer is our favorite brand because they last forever, unlike most trays you buy),
• biodegradable pots (spruce/other sustainable material, cowpots, paper pots, etc), or
• Ladbrooke soil blocks.

No matter what material you use for your seedlings, be sure to put a solid plastic seed tray or an old cookie sheet underneath them to keep water from dripping out onto your floor or furniture.

SOIL: Do NOT fill your seed cells with soil from your garden, since this tends to harden into an impenetrable brick. If you’re a new gardener or you’re not starting very many seeds, we recommend that you buy a ready-made organic seed starting mix. If you’re a more experienced (or adventurous) gardener or you’re starting a lot of seeds, you can use our DIY seed starting mix recipe to make your own:

• 4 parts screened worm castings and/or screened compost made from Berkeley hot composting method (purpose: introduce a massive amount of beneficial microbes to your seedlings while providing plant nutrition)
• 2 parts coconut coir (purpose: provide light, but well-draining growth medium for seedling roots)
• 1 part vermiculite (purpose: increase water & nutrient retention)
• 1 part perlite (purpose: increase soil aeration & good drainage)

Instructions: Mix all dry ingredients together until well blended. Then stir in water to get your seed starting mix moist (but not sopping wet) BEFORE you put the mix into your seed cells. You are aiming for the moisture level of a well-wrung kitchen sponge. We usually mix and wet a big batch in a wheelbarrow. Once wetted, this mix will expand significantly relative to its dry volume.

Organic seed starting mix and/or every ingredient you need to make your own DIY seed starting mix is available here in our Organic Gardening Supply Store. 

LABELS: Don’t forget to label the cells or containers to indicate the variety of seed as you sow your seeds. For our labels, we use either plastic strips or wooden popsicle sticks and write the broccoli variety on them with a permanent marker that won’t fade under UV light (like the kind you’d use to scrapbook with—we’ve had particularly good luck with metallic silver Sharpies) or a wax pencil (available at garden centers).

3. Germinating conditions

WARMTH: Once your seeds are sown, place your seed trays in the warmest spot in your home. The ideal temperature range for broccoli seed germination is 45° to 85°F; at the upper end of these temperatures your broccoli seeds will germinate in about 4-7 days. If the temperatures are at or below 50° F, your seeds may take an additional week to germinate. If you don’t have a super warm spot to germinate your seeds in you can buy soil warming mats that will maintain the soil temperature 10-20 degrees above the ambient room temperature. Heating pads (like the type you buy at the drugstore) can work, but heat settings vary from manufacturer to manufacturer and may make your soil too warm or cause it to dry out quickly. We’ve used them in a pinch, but check in on them frequently (until you know how it’s going to effect things) and only use them on the lowest heat setting.

WATER: To help with germination, make sure your seed containers stay moist, but not wet (about the consistency of a well-wrung sponge). Start by watering them every 24 hours, but if they look really damp hold off and check on them again in a few hours. Note: they will dry out faster on soil mats or heating pads.

4. Once they’ve sprouted

INDOOR LIGHT: As soon as your broccoli seeds have germinated/sprouted above the soil surface, place them in front of a south-facing window in your home (e.g. the window that gets the most sunlight throughout the day). We don’t have a particularly sunny window at our home, so we use florescent grow lights (just regular shop lights from the hardware store) hung overhead instead. It’s crucial that your seedlings get adequate light—an absolute minimum of six hours of direct light—otherwise they’ll quickly become weak and leggy. Tip: Periodically turn your seed trays so that the same side is not always facing towards the sunny window—this will prevent the side furthest away from the sun from getting leggy or stretching sideways towards the light.

OUTDOOR LIGHT (daytime temps over 45°F): When the daytime temperatures are over 45°F, you can start putting your broccoli seedlings outside in direct sun. However, if you don’t “harden off” your seedlings before exposing them to direct, unfiltered sun, you risk them becoming sunburned. You can read more about how to harden off your seedlings in the Transplanting Outdoors section.

At this point, you’ll need to consider nutrition, depending on whether your seed starting mix did or did not contain nutrition.

The first two leaves on your broccoli seedlings are called “cotyledon” leaves. The next leaves that develop are the first set of “true leaves.” About 10-14 days after germination, your broccoli seedlings will get their first true leaves.

5. Feeding them

1. No Nutrition In Seed Starting Mix – If there was NOT any nutrition (worm castings, compost, or slow-release fertilizer) in your seed starting mix, you’ll need to start feeding your seedlings immediately as detailed below.
2. Yes, There Is Nutrition In the Seed Starting Mix – If there was nutrition in your seed starting mix(worm castings, compost, or slow-release fertilizer), you won’t need to feed your seedlings immediately. You will want to keep an eye on your seedlings over the next few weeks as they grow and their nutritional needs increase. If growth seems slow or the plants leaves start to yellow, that’s a sure sign that they need more nutrition.

When/if your seedlings need nutrition, you have two options: 

1. Use Organic Liquid Fertilizer – Start applying a water-diluted organic liquid fertilizer 1-2 times per day. Organic fish, kelp, or squid emulsions all work well (available in our store). Dilution ratios vary from product to product, but watering at half-strength (half of what the bottle recommends for feeding mature plants) is a good rule of thumb. Warning: emulsion fertilizers are a bit smelly for about 20 minutes after you apply them, but it usually dissipates quickly. If you’re sensitive to smells, this may not be the best option for you. Also, be aware that over-fertilizing your plants can make them extra attractive to pest insects like aphids which can proliferate rapidly indoors since no predatory insects are around.
2. Put Them In Bigger Pots: This is also called “potting up” in gardening lingo. If your seedlings need nutrition or are running out of space in their smaller cells, you can transplant them into larger, 3-4 inch diameter pots or cells using a seed starting mix that contains worm castings, compost, or slow release fertilizer.

Next, keep a close eye on your seedlings to make sure they stay healthy: well-sunned, well-fed and well-watered until your planting date has arrived. If you sowed your seeds more intensely than a 1-2 seeds/cell, go ahead and thin them with sharp-tipped snips – enjoy them on salad or as a little snack!

You’re almost ready for transplanting…

Starting your Broccoli seeds outdoors

Like other plants in the brassica family, broccoli prefers cool, mild weather. We grow broccoli in our garden (Agricultural Zone 7b) from the last frost date of spring through early summer AND from late summer through winter. Broccoli can survive temperatures down into the low 20s (°F), especially if it has had time to adjust to cold weather. However, freezing temps will slow the plants’ growth rate and may cause foliar burning (leaf damage).  

Sowing Broccoli Seeds Outdoors

• For Spring & Summer Harvests: sow seeds starting 21-28 days before your last frost date
• For Fall & Winter Harvests: sow seeds in late summer, or about 85-100 days before your first frost date. Broccoli is cold-hardy and can tolerate frosts and light freezes well, but you can also use winter protection to extend the season. The florets will take longer to mature in fall than in spring since the days are getting shorter and cooler, not longer and warmer.

Planting

• Depth: Sow each seed about 1/4 inches deep.
• Seed Spacing: This can vary depending on the variety, but as a rule broccoli with larger heads need more space per plant than the ones with smaller heads or single florets. When first planting the bed, space each seed about 1 – 2 inches apart and then thin plants to a final spacing of about 10-18 inches apart for heading broccoli and 6-12 inches apart for sprouting broccoli (broccoli varieties that only produce single florets on multiple stems).
• Row Spacing: If you’re growing broccoli in rows, space each row about 18-36 inches apart depending on the size of your variety and the way you prefer to design your beds.

You can also plant broccoli more densely and eat the sprouts, microgreens and young leaves (all of which are a cancer-fighting superfoods), leaving behind the healthiest plants to grow to full maturity.

Transplanting Outdoors

If you started your seeds indoors, follow the instructions below. If you germinated your seeds outdoors in your garden, you can skip this section and head on over to the Sun, Soil & Water guide.

1. Hardening them off

Outdoor direct sunlight is always more intense than either indoor grow lights or light filtered through a window. Many new gardeners make the mistake of immediately transplanting their plants outdoors into direct sunlight before “hardening them off.” This mistake can cause extreme sunburn that severely damages or kills your plants. To be safe, plan to harden your broccoli seedlings off outdoors over the course of a week as follows:

• Days 1 – 3: Place your seedlings outdoors in a shady spot that will only get 2-4 hours of direct sunlight throughout the day.  Check on them every half hour if possible, especially on the first day.
• Days 4 – 5: Place your seedlings in a slightly sunnier spot that will get about 5-6 hours of direct sunlight.
• Days 6 – 7: Place your seedlings in a full sun spot.

Occasionally, your seedlings’ leaves may appear limp due to lack of water, so try to keep their soil moist, but not wet. If you notice your seedling leaves beginning to look white and papery, they’ve gotten sunburned; put them in a partly shady spot for a few days and allow them to recover.

Again, if you don’t properly harden off your seedlings, they can get severely sunburned, which will either slow their growth to a crawl while they recover or possibly kill them (if they’re small or weak). Also, be sure that you bring your broccoli seedlings inside any time the temperatures drop below 45ºF.

2. Planting outside

• Spring & Summer – Once your last frost date has passed and there are no temperatures below 45°F in your 10-day weather forecast, transplant your broccoli seedlings outdoors (note that summer broccoli is only recommended in cool regions).
• Late Summer, Fall, & Winter – You can continue to transplant your indoor-germinated broccoli seedlings from spring – summer and well into the fall in many climate zones. In milder climates you can grow broccoli through the winter with protection. Look at the “Days to Maturity” on your particular variety of broccoli (on the seed packet) and be sure you give yourself enough time to get a harvest near your first frost date (light frosts actually cause the broccoli to taste sweeter but hard freezes can kill it).

3. Plant at the correct depth, in actual soil

We know this may seem obvious to some people but you’d be surprised at how frequently new gardeners are unaccustomed to how deep or shallow to place a root ball and what constitutes real “soil” for filling in the surrounding hole.

Take a look at where your seedling decided to place its stem vs. its roots when it came up in your soil block or pot—the point where the stem extends above the soil and the roots spread below it is called the “crown” of a plant. Most transplants want to be placed at approximately the same depth that they “planted themselves.”

If your garden beds haven’t had compost or any additions that might feed your new seedlings, you’ll want to do that before you plant. We recommend you amend your soil with worm castings or a high-quality potting mix, or by adding a scoop of organic fertilizer.

We like to place the root ball only about ⅛-¼ inch deeper than it was in its pot so that we can sprinkle a thin coat of our garden’s soil followed by around ½ to 1 inch of mulch over the potting soil root ball (make sure not to pile soil or mulch directly against the plant’s leaves) to protect it from drying out at a different rate than its surroundings. 

When filling the hole back in around the root ball, the soil you use should not have recognizable chunks of mulch, kitchen scraps, leaves, lawn clippings, or other undecomposed organic matter since this can cause irrigation issues or injure your plant roots as organisms continue to break them down.

Mulches should always remain on the surface of the soil, not against the roots of the plant. If you have ever heard of mulches or compost “stealing” nutrients from garden plants, mixing these itemsinto the soil instead of letting them sit on top of it is what causes this problem. You can read more about your plant’s long term soil requirements in the Sun, Soil, and Water section.

4. Watering

Immediately after planting, give each newly planted broccoli seedling a deep watering around the base of the plant.

5. Two Tricks

Two final planting tips that will make your life much easier:

1) The Stick Trick – New transplanted seedlings are often “chopped down” by the aptly named “cutworms.” We’ve had 100% success stopping these pests. We simply find a stick roughly the same thickness as a toothpick and stick it in the ground right next to the stem of our seedlings. When the cutworms come along and feel around the seedling, it is tricked into thinking that the plant is too tough to cut down, so it moves along to its next victim.

2) Wood Chips/Mulch – We can’t overemphasize how important top-dressing your beds with organic matter such as finished compost, plant clippings, wood chips, or mulch is for building and maintaining healthy soil, regulating soil moisture and temperature, or blocking unwanted plants—aka “weeds.” After you plant your seedlings, make sure to put a layer of organic matter on top of the soil surface around your plants (without piling it against the stems) to feed soil organisms, prevent UV damage to the soil, retain water, and repress weeds if it’s not already there.

Sun, Soil & Water

Sun: Broccoli grows best in a full sun spot that receives at least 6 hours of direct sunlight per day.

Soil: Plant your broccoli in rich, fertile well-draining soils with lots of organic matter and a pH between 6.0 – 7.0.

Five techniques that you can use to drastically improve your soil health & biological fertility are:

1. “hugelkultur” (click here to read about this technique);
2. polyculture plant guilds (see “Guild Plants,” the next section in this guide);
3. top-dressing your soil with 3-6 inches of wood chips/mulch twice per year in the fall and spring;
4. using living cover crop mixes rather than leaving your soil fallow;
5. using compost from hot composting methods (Berkeley method) or worm castings (you can buy worm castings in our store). Apply the compost/castings on top of our beds and water them in or maximize the compost/castings over a larger area by making actively aerated compost teas (AACT) to be used as soil drenches or foliar sprays. Both applications drastically increase the quantity and diversity of beneficial microbes in your soil and on your plants.

These techniques can improve your soil fertility to the point that your plants will not require any additional fertilizer and virtually no additional water throughout the growing season once their root systems get established. We recommend that you NOT use non-organic/synthetic fertilizers as these will have a compounding harmful effect on your soil over time. Plan to build your soil fertility for the long-term using techniques that build biological soil fertility.

Water: Broccoli needs soil to be as moist as a well-wrung sponge; insert an index finger up to the 2nd knuckle to feel your soil’s consistency (it’s okay and normal for the top inch of soil to be drier unless your plants are still tiny seedlings with undeveloped root systems).

If your soil is healthy, your plants have established their root systems, and rain is regular, you may not need to provide any additional water to your mature broccoli plants. If you do need to water, water deeply (shallow watering can lead to shallower root systems); use approximately 1″ of water from a sprinkler or drip irrigation system (you can measure with a rain gauge).

Helpful Guild Plants/Companion Plants

Definition: A plant “guild” is a polyculture plant system (multiple plant species planted together) purposefully designed to create symbiotic relationships between species, increase plant productivity and generate higher survival rates amongst the individual plants in the guild system. If you’ve ever visited a “wild” ecosystem (mature forest or prairie), you’ve unknowingly seen plant guilds. Like people, plants perform better in communities than they do as isolated individuals.

Some Common Plants to Consider in Your Broccoli Guild:

Plants to AVOID Planting With Your Broccoli

• Large plants that will crowd or shade your broccoli

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Edible Landscape & Containers

Planting Broccoli in your Landscape

There is quite a bit of variation in the size, color, and shape of different types of broccoli, so you can be quite creative in choosing varieties and how to use them for maximum visual impact in your edible landscape. Our personal favorite is purple sprouting broccoli, which produces clusters of breathtaking purple florets that will continue to produce more side shoots as you harvest the older florets.

However, that doesn’t mean that the green-headed broccoli varieties don’t also make a showy display in an edible landscape as well!

Regardless of the color of their florets (which are technically dense clusters of unopened flowers), all broccoli plants are large leafy plants for the first stage of their existence. The big, round, blue-green leaves have a slightly waxy coating that makes water bead on their surface like tiny jewels after a rainstorm. Yes, the leaves are edible as well, and taste quite similar to kale, their close relative. However, broccoli leaves are a bit thicker and tend to taste better lightly cooked or fermented into sauerkraut. Older leaves should be treated like collards.

Given that they’re a relatively large cool-weather plant, we like to make them a centerpiece in a bed, encircling them with lower-growing plants like violas and pansies (both of which are also edible) in the winter or red lettuce varieties in the spring to provide nice color contrasts.

Hot Climate Zones

• In areas with hot spring weather (southernmost states), it’s best to plant broccoli with the intent of harvesting it in the fall/winter months (make sure to use winter protection once frosts occur). This means it is a perfect crop to start indoors and use the transplants for replacing summer items that have finished or are beginning to look ragged. It’s also a crop that needs some shade in summer heat (if planted in late summer for a fall harvest) so you can also tuck it between two taller plants that will keep it shaded until the weather begins to cool off. Plan for each broccoli plant to have around 2 square feet of space once it is mature (which means thinking about when its neighbors can be cut to give it the extra sunlight and elbow room it will need).
• Marigolds, cosmos, calendula, zinnias, or rudbeckia are flowers that tend to still be going strong at the end of the season and thus make good companions for designing with broccoli in your late summer-fall plantings. We particularly like to use varieties that flower in warm fall colors like yellow, orange, and red because they take on an additional glow next to silvery-blue broccoli. If you aren’t able to plan in advance, you can add pansies in these shades once the heat spell breaks.

Planting Broccoli in a Container

Container Spacing for maximum harvest – Minimum container size – 5 gallons (per 1 plants), approx. 12-14 in. diameter, 8-14 in. deep.

Ideally, each broccoli plant could have its own 5 gallon pot. Most gardeners underestimate the amount of space needed for growing these large brassicas – 2-3 ft. tall & up to 2 ft. wide. Broccoli is also a heavy feeder, so allow for frequent, light feedings and consistent moisture so the plant doesn’t prematurely bolt (go to flower). Make sure to thin to only 1 plant per container or to use a large trough or barrel planter.

For the greatest visual impact – Follow spacing instructions above. With these larger brassicas, it’s best to give them their own large pot and use clusters of smaller pots around them to create visual interest. As mentioned previously, broccoli plants are mostly leaves for the first stage of their existence. The leaves are large, round, and blue-green in color which can look very nice as an ornamental plant.

When choosing a pot, shades of blue bring out the blue tints in the leaves whereas purple, burgundy, and red provide an appealing contrast for it. Black pots are a modern looking foil while also providing the added benefit of absorbing sunlight and heating the soil on very cold winter days. Since overwintering brassica family plants such as broccoli stop growing and “wait” if the temperatures are lower than 40° F, this can help a crop mature more quickly.

Common Pests & Diseases

Broccoli: Outdoor Pests & Diseases

As a brassica, or cole crop (two synonymous names which refer to a large scientific grouping of related plant species), broccoli can be susceptible to the various diseases and insects that also affect cabbage, cauliflower, kale, Brussels sprouts, kohlrabi and other brassicas. Cornell University Extension has an excellent guide for identifying and organically managing various pests and diseases that can impact broccoli (and other cole crops).

Remember…

A healthy garden needs pests. Pest species provide food for beneficial species. A garden ecosystem that’s teeming with life will tend to hold the population of any one species in check. We’ve found that by focusing on improving our soil fertility and using polyculture plant systems that attract and support a wide variety of insects, we’ve virtually eliminated all pest and disease problems from our garden.

Please be thoughtful in your approach to these potential problems. Is your soil healthy and teeming with microbial life? Have you planted other beneficial plants throughout your garden system that might help with the problem? If you wait a few days, will the “pest” become the food of a predator? Observe your garden system and think holistically before taking any action that could disrupt the web of life (pesticides kill beneficial insects too, not just pest insects; fungicides kill beneficial funguses too, not just “bad” funguses; etc). Personally, we’d rather lose a plant than accidentally kill a colony of nearby bees.

Harvesting Broccoli

There are three basic varieties of broccoli:

1. Large-Headed – The most common varieties in grocery stores, they produce large, domed heads composed of numerous floret clusters. They’ll often produce small side shoots of florets after their main head is harvested.
2. Sprouting – These varieties grow produce lots of small heads and generally grow into bushier plants than other broccoli varieties.
3. Romanesco – These are usually sold as cauliflower, but occasionally as broccoli. Since both are from the same species (Brassica oleracea), we’ve included it here. Romanesco type varieties produce the gorgeous, swirled florets that mathematicians love (they’re a great example of the “Golden Ratio” seen in things as disparate as spiral galaxies and nautilus shells). These plants can grow quite large.

Broccoli Raab (aka Rapini)—this crop produces small flower clusters that look and taste similar to broccoli and is often mistakenly categorized as a broccoli. However, it is actually more closely related to turnip greens, another branch of the brassica order (and usually a different species that does not cross-pollinate with broccoli).

Enjoy the Variety

One of the many benefits of growing your own food is that you get a far broader culinary experience than you would if you could only buy produce from the grocery store. Broccoli (especially the sprouts) are well-established in scientific literature as one of the most nutritious superfoods on the planet, producing a rare compound called “sulforaphane” that is most potent when eaten from the whole plant (it breaks down over time and is not nearly as effective in pills and dietary supplements).

We typically plant far more broccoli seeds than we intend to let reach maturity, then harvest the smaller, weaker plants as we go. This allows us to enjoy a steady supply of greens throughout the growing season, while only saving the largest, healthiest plants for final harvest or seed saving.

You’ll want to pick the florets from the mature plants before the individual buds open and produce their tiny, elegant yellow flowers. Simply cut each floret at the base of its stalk and leave the rest of the plant to continue growing. Most broccolis will continue to produce new florets, even if they’re smaller than the main head.

Preparing Broccoli

There is only one “wrong” way we know of to make broccoli (or most vegetables for that matter): boiled. When you boil broccoli, much of its nutrition is lost in the water that you end up pouring out, and the plant is turned into a mushy, relatively flavorless impostor. Instead, you can steam it, stir fry it, bake it or it eat it raw; just don’t boil your beautiful broccoli harvest! One possible exception is if you are making a soup or other recipe that utilizes the leftover cooking liquid so that the water-soluble nutrients aren’t dumped down the drain.

Saving Seeds

Seed saving is a critical step for ensuring that our seeds are passed down from generation to generation, so please give it a try and also be sure to share your seeds with other people! Another benefit: seeds you’ve properly saved from your own garden will be better adapted to your specific growing environment via natural epigenetic processes.

Broccoli can act as an annual or as a biennial plant, meaning it usually produces seeds during the same year you plant it but if not, it may need to experience a cold spell first. In many regions, starting them in the cold early spring is enough to get them to bolt as the weather warms but for late plantings and/or certain regions you may need to overwinter them so they can produce seeds the following spring/summer.

If necessary, you can overwinter broccoli as follows in order for the plant to produce seeds:

• Cold climate regions(where winter temps drop below 20 °F)
  • Option 1: Heavily mulch around your plant with leaves or straw, covering as much of the plant as possible. Cover the entire plant, mulch and all with a breathable covering (such as a frost blanket) to help hold the mulch in place and trap heat.
  • Option 2: Dig up the plant, roots and all, and store in a conditioned environment until the ground thaws in the spring.
• Moderately cold regions (where winter temps rarely dip below mid 20°F) – Put 3 – 6″ of mulch (wood chips, leaves or straw) around the base of your plants to better insulate the roots. Anytime the temperatures are forecasted to drop into or below the mid 20s (°F), cover your broccoli with a frost blanket or old sheet. If you use plastic as a cover, make sure the plastic is not touching the leaves or it can cause them to freeze.

If you’ve had to cover your plants for the winter, uncover them as soon as temperatures are no longer dipping into the teens. As the weather continues to warm, the broccoli will start producing new greens. Don’t pick the new greens, instead allow them to grow and provide energy to the plant and to new seed formation. Florets will form and begin producing beautiful yellow flowers that will soon become seeds

You can save your open-pollinated broccoli seeds as follows:

• Select Healthiest Plants For Winter Storage – Select only the strongest, healthiest plants and eat the others. Ideally, you need to leave at least five broccoli plants close to each other to ensure proper pollination occurs. If you plan to maintain a variety for 3 or more generations, it is strongly recommended you use at least 20-50 plants for your seed saving efforts in order to preserve genetic diversity. Otherwise, we recommend refreshing your seed stock with professionally grown seed every few years.
• Avoid Cross Pollination – Broccoli is insect-pollinated and can be cross-pollinated by other plants bred from Brassica oleracea (cabbage, cauliflower, kale, etc). To make sure you’re producing a seed that’s true to the parent, don’t grow other simultaneously flowering Brassica oleracea varieties any closer than a 1 mile radius (if you live in an open field-like setting) or .5 mile radius (if you live in an area with lots of physical barriers (houses, forests, etc).
• Harvest Seeds – The pollinated flowers will turn into long, thin seed pods. As they mature, the seed pods will turn brown. Once the majority of the seed pods have turned brown, cut the seed stalks at their base and store them indoors in a dry location for 2-3 weeks, allowing the seeds to fully dry and mature.
• Thresh and Store Seeds For the Future – Once dried, the seed pods can easily be threshed or rubbed together in your hands to remove the tiny round seeds hidden inside. Remove as much dry debris as you want, then store your broccoli seeds in an airtight container (add rice or silica packages to hold any moisture). You can also store the seeds in envelopes, although this will make them more susceptible to moisture damage over the course of several years.

Properly saved and stored in a cool, dry environment, your broccoli seeds can remain viable (e.g. able to be grown) for 3 years or longer. Plant and share them so their grow journey continues!

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