We have our gardener friends in England to thank for this article about how to grow purple sprouting broccoli. While in the US we know all about broccoli and, to a lesser extent, broccolini and broccoli rabe, the British have added how to grow purple sprouting broccoli to their repertoire—and so can you. In this article, I’ll cover just why and how to grow purple sprouting broccoli, from seeding to harvest and overwintering.You’ll guess from the name that this vegetable is indeed purple. It also produces side-shoots instead of one central head, giving the plant an interesting shape as well as color. It’s a great plant for adding variety to your vegetable garden and a great vegetable for adding nutrition to your plate.

Meet purple sprouting broccoli

Picture a broccoli plant with many small, purple broccoli heads instead of one large, green broccoli head. This is purple sprouting broccoli. Its unique appearance is enough to make anyone want to learn how to grow it.

Eating this vegetable, you’ll find the taste to be the same as regular broccoli, while the texture is a bit more tender. The plant has the same cultivation needs, which you’ll read about in a moment.

Purple sprouting broccoli is a hybrid cultivar of Brassica oleracea. This species in the brassica family has been differentiated into cabbage, broccoli, cauliflower, kale, kohlrabi, and Brussels sprouts. Broccoli (Brassica oleracea var. italica) can grow as a head or in a multi-stemmed, sprouting habit. This is where we find purple sprouting broccoli.

Despite its similar appearance, this type of broccoli is a different cultivar than broccolini (Brassica oleracea var. italica x alboglabra) and a different species than broccoli rabe (Brassica rapa).

Why you should be growing this veggie

Why bother learning how to grow purple sprouting broccoli? Well, this plant has a lot of benefits packed into its many shoots. Here are some:

• Purple sprouting broccoli matures in late winter or early spring, when there’s little else growing in the garden. You may be able to make a harvest from late February to April.
• You can eat the leaves as if they were kale, even before the plant produces its broccoli shoots.
• Its funky appearance in the garden will make your visitors do a double-take.
• It grows during the coolest part of the year, opening up that garden space to grow other crops from spring through late summer.
• Nutritionally, purple sprouting broccoli has great benefits, including the anthocyanin antioxidant compound, which may help protect against disease and improve our vision and neurological health.
• This veggie cooks quickly, sautéing or steaming in less than 5 minutes. Unfortunately, the florets do turn green when cooked, but you can still enjoy their purple hues before dinnertime by eating them raw to preserve their purple color.

The best time for growing purple sprouting broccoli

Other names for this crop are late-sprouting broccoli and winter-sprouting broccoli. Here’s why: Like other cole crops, purple sprouting broccoli enjoys growing in cool weather. In fact, purple sprouting broccoli needs a vernalization period, which is 6 to 8 weeks of temperatures below 50 degrees F, to trigger the plant to produce shoots rather than just leaves.

Ideal growing conditions

Purple sprouting broccoli is most likely to thrive in climates with an average winter low of 15 to 40 degrees F. This gives the plants the vernalization they need without plunging them into temperatures that will damage or kill them. However, gardeners in colder climates can often successfully grow purple sprouting broccoli under mini hoop tunnels. In my USDA Zone 6 garden here in Pennsylvania, I cover the plants with a hoop tunnel covered with a double layer of plastic just before freezing temperatures arrive. I leave the plants covered all winter long and remove the plastic in mid-March. I start checking under it for edible shoots in early March, depending on the weather.

This veggie is not a good candidate for spring planting because weather that’s too hot will not only prevent formation of florets but also give the plant a bitter taste and deformed stems and leaves.

Preparing the soil

You can guess that because it’s a type of broccoli, how to grow purple sprouting broccoli will involve amending the soil for good drainage and fertility. Add compost to your soil ahead of planting. Loose soil will help these plants establish their root systems. Set up your plants for growth in full sun with a soil pH of 6.0 to 7.5.

When to start purple sprouting broccoli seeds

The seeds germinate and grow quickly. Understand your variety’s days to maturity to know when to start seedlings and transplant them into the garden. You want them to go into the winter at the right stage of growth, which is about 60% to 75% of the way to full grown. This gives them the most resilience in the coldest weather.

Starting seeds indoors under grow lights yields better results than direct seeding. Get started 3 to 4 weeks before you want to transplant. They germinate best at soil temperatures higher than 75 degrees F. Seedlings will thrive at 60-degree air temperature. I sow my purple sprouting broccoli seeds in late July and transplant them out into the garden in late August or early September. By the time cold temperatures arrive and I need to cover the plants with my hoop tunnel, they are about 75% full grown.

Transplanting into the garden

Wait until seedlings are 4 to 6 inches tall before transplanting. Add a high-nitrogen fertilizer when transplanting if your soil test shows this nutrient lacking.

Set up the plants with 12 to 24 inches in between with rows 18 to 36 inches apart. These are surprisingly large plants for producing such small shoots.

Caring for purple sprouting broccoli plants

Purple sprouting broccoli is a thirsty and hungry plant. Keep the soil well watered, and mulch around the plants to maintain soil moisture and reduce weeds.

As the plants begin producing their florets, give them a boost with a balanced fertilizer.

Because of the plants’ size, they may need staking or cages. Pay attention to your plants’ growth so you can be proactive about supporting them.

When and how to harvest purple sprouting broccoli

Your purple sprouting broccoli’s harvest time is variable, depending on the variety you’re planting, your weather, and more. This is a challenging part of learning how to grow this crop: the waiting. Early, mid-, and late-maturing varieties mean you can wait anywhere from 180 to 200 days for sprouting broccoli florets to form.

The first sprout to appear is the central head, which will be the largest. Let it develop into a small broccoli head, or snap it off right away so the plant puts its energy into producing sprouts right away. The smaller side shoots are the main attraction in learning how to grow purple sprouting broccoli. You should be able to harvest these every few days for the next few weeks.

How to overwinter the plants

Planting this vegetable at the right time is the key to overwintering. Because our seasonal weather is becoming more difficult to predict, successful overwintering may require some trial and error in your garden. Field trials by growers in the US Pacific Northwest found transplanting seedlings in mid- to late- August set up the plants for the best success in overwintering there.

Potential problems

Purple sprouting broccoli has such a long growth period that the potential for problems is greater than if you were growing a quick crop like radishes. You may get tripped up in learning how to grow purple sprouting broccoli a few ways:

1. Overwintering in an unpredictable climate is, of course, a challenge, as you read above. An unusually cold snap or not enough cool weather could either kill the plants or prevent them from producing their shoots.
2. A common disease to affect this vegetable is black rot. This fungus appears as yellow spots on leaves that eventually turn brown and black. A copper fungicide can control this disease.
3. Just as insect pests enjoy broccoli, they also enjoy this plant. Cabbage worms, aphids, and flea beetles are three common bad guys. Cover your seedlings with row cover when you transplant them to give the plants a chance to grow before these pests arrive.

Go purple

From the United Kingdom to the United States, purple sprouting broccoli is a tasty and fun crop to try out in a fall and winter garden. How to grow purple sprouting broccoli requires the right gardening climate—cool but not too cold—and patience in waiting for the harvest. Give the plants rich soil and direct sunlight, and keep them watered and protected from their insect enemies. In return, you’ll receive weeks of fresh, tender broccoli shoots and an early season vegetable harvest, not to mention these interesting-looking plants to enjoy while little else is happening in your garden.

For more broccoli-growing advice, check out the following articles: 

• How to deter cabbage worms
• Growing broccoli from seed 
• The best broccoli plant spacing 
• How to harvest broccoli 
• How to freeze homegrown broccoli