Rapini, also known as broccoli raab or rabe, shares a familial connection with turnips. Its unique characteristic is the formation of small, broccoli-like flower heads in certain varieties when they’re ready to harvest. This versatile green has an intriguing history – its medicinal properties were likely cultivated in China, but larger, milder-tasting varieties emerged as a vegetable staple in Italy, where it’s cherished alongside winter radicchio and other bitter greens.
Rapini Varieties
For those who believe rapini is the perfect fit for their discerning palates, cultivating these varieties at home can be a rewarding experience. Here’s a selection of well-known and easily sourced options to get you started.
Quarantina
Quarantina is a popular rapini variety that excels in containers or square foot gardens due to its ability to thrive in close proximity. This rapid-growing cultivar is also renowned for its short harvest time, taking just 40 days from sowing to maturity. Its suitability for spring or fall planting makes it an attractive choice for gardeners.
However, Quarantina’s tender nature means it will bolt and become bitter if exposed to excessive heat, so it’s essential to ensure temperatures remain cool during most of its growing period. For those seeking a slightly longer harvest time, the ‘Sessantina’ (70 day) and ‘Novantina’ (90 day) varieties offer similar characteristics, albeit with larger plants that require more space.
The higher the number in the name, the greater the plant’s size will be, necessitating around twice as much space for ‘Novantina’ compared to Quarantina.
Spring Raab
Spring Raab is a rapid-growing variety that’s ready for harvest in approximately 45 days. Its relatively high heat tolerance makes it an excellent choice for regions with short cool seasons. While it can thrive in warm temperatures, consistent watering is crucial to prevent bitterness. Notably, this cultivar excels when planted in the spring, although it can be grown in the fall as well. However, for successful overwintering, extremely mild climates are required.
Zamboni
Rapini, despite its name inspired by an ice rink surfacer, exhibits moderate heat tolerance. Its maturation period stretches to around 65-70 days, making it less prone to bitterness and bolting compared to some of the faster-harvesting varieties. This variety proves suitable for early spring planting in southern climates, provided a frost-free window is ensured.
However, prolonged exposure to extremely cold temperatures can cause stress, necessitating either post-frost planting or protective measures during harsh weather. Additionally, rapini performs well for fall harvests, but it’s crucial to initiate the process at least 2.5-3 months prior to the onset of cold weather to guarantee a bountiful yield.
Riccia di S. Marzano
Rapini, also known as broccoli raab, boasts an exceptional flavor profile, with its leaves and heads alike being a delight to culinary enthusiasts. While it may require slightly more attention than other varieties, the effort is well worth it for those seeking to elevate their cooking game. One of its most striking features is its unique, curly leaf shape, reminiscent of Lacinato kale.
As a ‘sessantina’ variety, rapini takes approximately 70 days to mature, making it essential to plant during periods of cool, mild weather with no risk of frost or excessive heat. For optimal results, growers should be mindful of these specific conditions to unlock the full potential of this delectable crop.
Variety Warning
When choosing among various rapini varieties, it’s essential to acknowledge the common confusion surrounding this leafy green. Many people get rapini mixed up with its close relatives – broccolini, sprouting broccoli, and even turnip greens. It’s crucial to understand these differences in order to select the perfect variety for your culinary needs.
Turnip Greens vs. Rapini
Rapini, also known as broccoli raab, shares a common ancestor with turnips. Unlike turnips, which are primarily grown for their roots, rapini has been cultivated for its flowering heads. Interestingly, some varieties of rapini are harvested for their leafy stems rather than the flowers themselves. This leaf-style rapini can sometimes be mistaken for turnip greens, but they’re actually distinct. While turnip greens belong to a group of biennial plants, rapini is an annual species.
Broccolini vs. Rapini
To further complicate matters, there’s also broccolini – a hybrid variety of broccoli that bears a striking resemblance to rapini. What’s more intriguing is that despite their visual similarity, they share no genetic ties, aside from being part of the broader Brassica family.
Sprouting Broccoli
In addition to the more familiar single-headed varieties, some broccoli plants exhibit a unique trait known as ‘sprouting’. This type of broccoli produces multiple smaller heads, often referred to as ‘broccolini’, which can be harvested individually as they mature. This characteristic is distinct from its single-head counterparts, offering gardeners and cooks an exciting opportunity for culinary creativity.
Seed Buying Tips
To avoid mistaking rapini seeds with those of another broccoli type plant, it’s crucial to verify the scientific name. Look for cultivars bearing the name Brassica ruvo. Additionally, when sourcing seeds from companies specializing in European or Italian varieties, you may need to search under the alternative name ‘Cima di rapa’. This ensures a precise identification and guarantees the authenticity of your rapini seed purchase.
How to Plant Rapini
While rapini thrives in the Mediterranean climate of Italy and coastal California, characterized by cool to warm temperatures and low humidity, it’s not impossible to cultivate this vegetable elsewhere. With some extra attention and consideration for its needs, you can successfully grow rapini even in your greenhouse or a controlled environment.
When to Plant
Rapini is a versatile vegetable that can be cultivated from early spring to fall, although it tends to lose its sweetness in hot weather and performs best in cooler temperatures. A notable limitation is its lack of cold hardiness, requiring protection from frost and prolonged periods of cold weather. Furthermore, rapini has a tendency to bolt when temperatures consistently reach above 80℉ for several consecutive days.
Therefore, it’s essential to target planting after the risk of frost has passed, allowing for a sufficient number of cool to moderately warm days for optimal growth.
Starting Seeds
To successfully grow rapini, begin by starting it from seed in the garden or a container that’s at least 18-24 inches deep. If necessary, you can start seeds in cells, pots, or soil blocks and transplant them later, as long as you handle the roots gently to avoid damaging them. When transplanting or potting up, make sure to do so before the roots outgrow their original medium. This will ensure a healthy start for your rapini plants.
Rapini seeds can germinate at temperatures as low as 55℉, although optimal rates of germination occur between 65-75℉. Germination typically takes between 3-10 days, depending on your specific conditions and environment. When sowing the seeds, plant them to a depth of about 1/8 to 1/4 inch deep, or you can also sow them on the surface and cover with a thin layer of compost.
Soil and Sun Requirements
For optimal rapini cultivation, it’s essential to provide deep, nutrient-rich soil teeming with organic matter. The ideal pH range for this cruciferous delight is 6.0-7.0. While rapini can thrive in clay-based soils, incorporating a few inches of compost into the mix before planting will significantly boost its performance. Similarly, sandy soils can also support rapini growth, as long as they’re amended with a generous helping of compost.
When it comes to light exposure, full sun is generally ideal for rapid growth; however, in hot climates, a bit of afternoon shade can be just what’s needed to ensure a tender and flavorful harvest.
Plant Spacing
The spacing requirements for rapini plants depend on the number of days until harvest. For varieties that mature in 40-60 days, about 6 inches of space around each plant is ideal. However, if you’re growing longer-maturing varieties that will grow significantly larger as they develop, add an extra inch of space for every 10 days beyond the initial maturation period.
This means that varieties taking 70 days to mature require approximately 7 inches of spacing, while those requiring 90 days need around 9 inches and so on. While such slow-maturing varieties are less common in the US market, some can fill a square foot of space and take up to 120 days to reach maturity. Additionally, if you’re working with less fertile soils or humid climates, consider providing each plant with a bit more breathing room to promote good air circulation and faster growth.
Caring for Rapini
Watering
To facilitate rapid growth, maintain consistent moisture levels for rapini plants. While they can tolerate short-term droughts similar to their turnip relatives, they become increasingly bitter if water scarcity persists. A regular watering schedule is crucial. In addition to keeping the soil consistently moist, deep watering encourages root development.
This not only promotes deeper soil penetration but also cools the roots, resulting in sweeter and less prone-to-bolting plants compared to those with shallow root systems.
Fertilizer
While compost can provide adequate nutrition for rapini, incorporating passive compost tea – especially when using vermicompost – into your routine may yield additional benefits. Specifically, this practice has been observed to enhance leaf resistance against insect-related damage, potentially leading to a healthier and more resilient crop.
Weeding and Mulching
When it comes to rapini cultivation, a key consideration is its natural ability to outcompete weeds through rapid leaf growth. As the plant matures within a few weeks of planting, its dense foliage will effectively suppress weed development and retain soil moisture. This native trait eliminates the need for mulching, which can sometimes unintentionally create an environment conducive to slug activity that might impede healthy leaf production.
In place of traditional mulching methods like straw or grass clippings, it’s recommended to focus on regular weeding until your rapini plants begin to produce a substantial leaf canopy. Alternatively, you can also plant additional seeds and carefully thin out seedlings to harvest baby greens as your primary plants reach maturity and require more space.
Companion Plants for Rapini
While comprehensive studies on rapini’s companions may be scarce, my own experiments and observations suggest that the following plants make excellent companions for a thriving rapini crop. When paired together, they seem to create a harmonious balance that benefits both plants involved.
Best Companions
Worst Companions
In addition to broccoli, other brassicas that are worth considering include cabbage, turnips, and mustard. Similarly, cucumbers and other types of squash can also be a great addition to your garden. These plants all belong to the same plant family as broccoli, and share many similar growing requirements and characteristics.
Common Problems and Solutions for Growing Rapini
Rapini, a member of the brassicas family, may be susceptible to pests and diseases similar to those affecting cabbage and other related plants. However, it’s worth noting that my personal experience with rapini has been pest- and disease-free. That being said, there are certain conditions under which rapini is more likely to encounter issues. These include hot weather, poor soil quality, or inadequate watering.
Diseases
When it comes to rapini, there are several diseases that can affect its growth and health. One of the most common is Alternaria Leaf Spot, which is characterized by yellow, dark brown to black circular leaf spots with target-like concentric rings. This disease thrives in temperatures between 60-80℉ with high humidity, but it’s generally cosmetic and not lethal to rapini.
To prevent transmission and slow infection rates, it’s essential to remove diseased leaves, water the soil rather than the leaves, and ensure good air circulation and soil drainage. On the other hand, Clubroot is a more serious issue that impacts all members of the brassica family. It starts with yellowing leaves and can be distinguished from other leaf-yellowing diseases by checking for swollen, distorted, or galled leaves.
While mature plants may survive and produce new growth when infected, young plants are often killed off by this disease. To reduce the risk of Clubroot, it’s crucial to use a fertilizer with calcium and magnesium and apply boron if your soil is deficient. However, it’s essential to note that boron can be toxic to soil if misapplied, so make sure to test your soil and follow application instructions carefully.
Regular crop rotation is also critical in minimizing the risk of Clubroot in your garden. Another disease that affects rapini is Damping Off, a soil-borne fungus that thrives in humid conditions. This disease typically affects young seedlings started indoors rather than direct in the garden. To prevent Damping Off, avoid starting seedlings in humid weather and keep the soil uniformly moist but not boggy. White Rust is another issue that rapini plants can face.
This disease is caused by oomycetes and acts like a fungal pathogen. While it’s usually not lethal, severe cases may require organic fungicides rated for use with White rust or blister rust to produce a good crop.
Rapini Pests
Aphids are tiny insects that thrive on plant stems and leaves, often congregating in large numbers on tender shoots and young foliage. As they feed, they produce honeydew, which attracts ants – a common sight for gardeners who notice the ants feasting on the sweet excrement before spotting the aphids themselves. While aphids rarely prove fatal to rapini plants, they can weaken already stressed specimens and make them more susceptible to other diseases.
They also play a role in transmitting fungal pathogens between plants. To manage an infestation, gently rub affected leaves with a soft cloth and mild soap solution. Harlequin bugs are true insects that, unlike beetles, undergo incomplete metamorphosis. This means their juvenile and adult forms share a striking resemblance. Their eggs, shaped like the iconic Cat in the Hat hat, stand out due to their black and white coloration.
These leaf suckers can mar the appearance of rapini plants and even cause premature mortality in longer-season varieties. Promptly squash any you encounter to prevent breeding. As an added tactic, consider planting cleome, mustard, or horseradish as trap crops, as harlequin bugs tend to prefer these over rapini. Flea beetles are another cosmetic pest that can mar leaf surfaces.
While they don’t typically harm or reduce productivity in rapini plants, row covers and tape traps can help mitigate damage. Many gardeners accept the small holes left by flea beetles as a natural feature of organic vegetable cultivation. Slugs and snails also have a taste for rapini leaves. Employ standard methods to control slug and snail populations to prevent them from causing harm.
Harvesting and Storing Rapini
Rapini, like kale and mustard, is a versatile crop that can be harvested repeatedly for its leaves. However, many gardeners wait patiently for it to produce the coveted flowering heads, similar to broccoli. When these flowers are in full bloom, they’re best enjoyed at their peak tenderness.
To harvest the flowering heads, simply pluck them as they form and before they open up fully. Rapini plants typically feature a central stem with several smaller offshoots.
Start by harvesting the main shoot down to the base of the plant, then check back daily to snag each side stalk at its peak.
Alternatively, you can harvest the entire plant at its base and enjoy the leaves, stems, and flowering heads in various stages of development when the central stem is ready for the taking. Once harvested, rapini keeps remarkably well in your fridge crisper for up to a week. For optimal flavor and texture, however, it’s best to harvest and cook it on the same day.
If you do need to store your harvest, you can steam wilt them and keep them refrigerated for a few days or frozen for later use.
Saving Rapini Seeds
When the flowers of the rapini plant have faded, it’s time to focus on harvesting its seeds. This process typically takes around two months from the initial flowering. While rapini is capable of self-pollination, much like turnips, you’ll often see a significant improvement in yields with the addition of multiple plants. For optimal results, consider growing six or more plants that are specifically dedicated to seed production, as this will facilitate cross-pollination.
It’s also worth noting that rapini has the potential to cross-pollinate with turnips, so it’s essential to maintain a safe distance between these two varieties. As a general rule of thumb, keep your turnip flowers at least 100 feet away from your rapini plants to prevent any unwanted mixing. Once harvested, rapini seeds can be stored for up to five years. In my experience, I’ve found that storing seeds for three years or less tends to yield the best results.
Rapini Alternatives
Conclusion
While rapini may not be a staple in many American households yet, its unique flavor profile and versatility make it an exciting addition to any dish. If you’re familiar with other peppery Italian greens like radicchio and arugula, you’ll likely find rapini’s slightly sweet and earthy undertones a refreshing change of pace. To get started, begin by planting a 40-day variety as a trial run, and then graduate to longer-maturing options that suit your local climate.
With its hardiness and adaptability, it’s no surprise that rapini is quickly gaining popularity among gardeners and chefs alike.
