Companion plants for leeks

Best Companions

Carrots, Apples

Tomato, Alliums

Companion Planting is the placement of various crops in close physical proximity to one another so as to symbiotically compliment each others health, vigor, growth and the flavor of their produce. It also naturally involves separating plants whose development is antagonistic to each other.

For the purpose of companion planting, leeks should generally be treated like onions. They have very few natural enemies, the leek moth being one of the few. They should be considered as a candidate for companion planting more for their protective qualities.

Leeks are related to onions, garlic and chives , they prefer full sun though partial shade is tolerable. They require moderate water and nutrients. Companion Plants should have similar soil, sunlight and watering requirements as well as an additional attribute such as pest or disease suppression, flavor enhancement or so forth. Plants that meet this criteria and make good companion plants for leeks are carrots, fruit trees – apples, celery, parsley, garlic, onions, beets and tomatoes.

Other Alliums

Leeks will grow well with their cousins – Onions, shallot, garlic due to similar cultural, nutrient and soil requirements. This scenario is workable, however it could blow up in your face as in addition to sharing needs they also share diseases and insect enemies. If you are planning to inter-plant leeks with other Onion family plants do so in moderation. A small patch of leeks and garlic, or leeks and onion is not so bright a shining beacon for pests and pathogens as a big patch, or a few scattered small patches here and there in your garden.

Beans and Legumes

Beans and legumes are not good companions for leeks or related plants. You can probably do it , and get away with it without any noticeable negative consequences about 75% of time. It has been documented however that alliums stunt the growth of beans, legumes, peas etc.

Alliums exude a compound that inhibits growth in beans and legumes. A compound found in garlic and to a lesser extent leeks known as “ajoene” acts as an anti-fungal agent in some cases, but has negative effect in others, the growth of beans and legumes being one. *See Reference at Page Bottom

A Guide to Root Vegetables

Truth: root vegetables can be intimidating. Most of them have thick, strange looking skin and long stems with leaves sprouting out of them. Let’s face it, some of them look like they’re from outer space. Some root vegetables are given the cold shoulder because they have the reputation of tasting earthy and even bitter. But hold the phone. This guide to root vegetables can serve as inspiration to embrace the outcast extraterrestrial roots, as they are not only amazing for your health, but they are versatile in the kitchen and absolutely delicious when prepared properly.

The Health Benefits of Root Vegetables

Roots are some of the most nutrient-dense vegetables in the world. While each root contains its own set of health benefits, they share many of the same characteristics. Yams, beets, parsnips, turnips, rutabagas, carrots, yuca, kohlrabi, onions, garlic, celery root (or celeriac), horseradish, daikon, turmeric, jicama, Jerusalem artichokes, radishes, and ginger are all considered roots.

Because root vegetables grow underground, they absorb a great amount of nutrients from the soil. They are packed with a high concentration of antioxidants, Vitamins C, B, A, and iron, helping to cleanse your system. They are also filled with slow-burning carbohydrates and fiber, which make you feel full, and help regulate your blood sugar and digestive system. This factor, plus the high-octane nutrients and low calories, make roots excellent for people who are trying to lose weight, or simply stay healthy.

Adding up all of the nutrient qualities, root vegetables are disease-fighting, immunity and energy-boosting, and are also extremely versatile in cooking.

What is the Best Season for Root Vegetables?

Most root vegetables are available year round, but their peak season is fall through spring, with the exception of beets, which are best summer through fall. When in-season, roots have a deeper, sweeter flavor and tend to be juicier, but they are one of those plants that seem to stay consistently great all year long.

How Do You Choose Roots?

Selecting good root vegetables is the opposite of selecting good fruit–the harder, the better. They should be smooth and free of gashes or bruises. When choosing roots that come with leafy greens (a bunch of beets, for example), make sure the stems and leaves of the greens are firm and bright.

How Do You Store Root Vegetables?

While you certainly don’t need to have a root cellar to purchase and enjoy roots, they are best stored in a cool, dark, humid room. When storing them in the refrigerator, keep roots in a paper or plastic bag in the crisper. Storing them uncovered causes them to soften and go bad quickly.

What Are the Various Types of Roots?

There are almost too many to mention here! These are some of my favorites to cook with:

Sweet Potatoes & Yams // Among the most usable, user-friendly, and palatable roots, sweet potatoes and yams are great mashed, pureed and made into soup, roasted, and baked into muffins, cookies, pancakes and so much more. They can be used both in sweet and savory applications and are very well-matched with coconut milk, honey, maple syrup, orange, cinnamon, ginger, pecans, cashews, walnuts, raisins, and curry powder. Yams are often confused with sweet potatoes, and although they can be used interchangeably, there is a difference.

Beets // Touted as a superfood, beets are among the healthiest foods on the planet. They’re full of beta-carotene and betalains, which are antioxidants and anti-inflammatory. Beets have an earthy, sweet flavor, and are best when roasted, steamed, or left raw and shredded. Golden beets are typically slightly sweeter than red beets. I find citrus (particularly oranges or clementines), blueberries, goat cheese, walnuts, ground cumin, cinnamon, and tahini are excellent compliments for beets. This Roasted Beet & Fig Salad is one of my go-to recipes.

Parsnips // Parsnips have a cinnamon-y flavor and resemble large white carrots (or albino carrots, as I like to call them). They are harder than carrots and have a deeper, warm flavor. I find parsnips are best used in soups, pureed into a mash, or sliced thinly for a parsnip gratin. Parsnips are complimented by nutmeg, cream, and thyme.

Turnips // While turnips are versatile, they are very subtle in flavor, which makes them great for pairing with more strongly flavored vegetables. They are great roasted, sautéed, or included in vegetable stir fry. You can also combine turnips with herbs, or use them in tomato-based chunky soups or creamy pureed soups.

Rutabagas // Similar to turnips, rutabagas are subtle in flavor. They are harder than turnips and taste a bit more earthy. Best when pureed or roasted, rutabagas go well with herbs, particularly dill, as well as lime and Indian spices.

Carrots // Crisp and sweet, carrots are perhaps the most popular root vegetable because they are perfect for eating raw. They match well with just about any vegetable in both cooked and raw applications and can be paired with any spice or herb.

Yuca Root // Starchy and subtle in flavor, yuca is often used the same way in cooking as potatoes. It is best when roasted or fried, and it tastes like a potato wedge, although the texture is somewhat stringy. Yuca can be paired with a wide variety of herbs, spices, cheeses, and sauces.

Kohlrabi // Underneath the thick skin and strange tentacles of kohlrabi lies juicy, crisp flesh. Kohlrabi can be cooked or left raw, and it makes delicious oven-baked fries. It can also be made into a mash, pureed into soup, or sliced thinly and added to salads. Combine kohlrabi with any of your favorite spices and herbs.

Ginger // Similar to beets, ginger is a powerhouse root due to its natural antibiotic, anti-inflammatory, and detoxification properties. With a sweet, spicy, yet creamy flavor, ginger can be used in a large variety of foods and drinks. Ginger is most often used in ethnic food alongside coconut milk and a variety of vegetables, but its uses are virtually endless. Feeling like you’re getting a cold? Drink a kale-ginger detox smoothie and you’ll feel like a million bucks!

Onion & Garlic // There is debate as to whether or not onions and garlic are true root vegetables because they are bulbs and do not grow as deep as most of the other roots. Onions and garlic are widely used in cooking, as they both add a great deal of flavor to any dish, both raw and cooked. Both are considered to be heart-healthy veggies, increase circulation, and act as an anti-inflammatory.

How Do You Prepare Root Vegetables?

Roots can be prepared every which way. Experiment and discover what your favorite cooking methods and flavor profiles are!

Raw // Because root vegetables are hard and have an earthy flavor, they are most palatable when cooked. For those who prefer leaving their vegetables raw, carrots, beets, radishes, and jicama are good choices for slicing thinly or grating and tossing with dressing and/or other vegetables and fruit.

Steamed/Boiled // Steaming or boiling root vegetables is a great way of prepping them in order to mash or puree them. Mashed celery root or yams make healthful replacements for mashed potatoes, and any root can blended up into a creamy root soup.

Roasted // Roasting any type of vegetable cultivates flavor and texture. Chop up your favorite vegetables, drizzle them with olive oil, sprinkle them with spices, and roast them in the oven. Balsamic Roasted Root Vegetables are an easy and delicious dish, and they’re a guaranteed way to get the vegetable-averse to eat and enjoy their veggies. You can also thinly slice roots, lay them on a baking sheet, and roast them into root chips.

Sautéed // Making a vegetable sauté or stir fry is a great way of preparing root vegetables. This is a relatively quick and easy cooking method, and all sorts of flavors can be added to the dish. When cooking with other types of vegetables besides roots, sauté the roots first, as they take longer to cook than other vegetables.

Grilled // Roots can be peeled, thinly sliced, brushed with oil, and grilled along with other summer vegetables. This adds a smoky flavor into the roots and softens their earthiness.

Hopefully those of you who were once on the root fence are now sitting cozy on Team Root. Good luck on all your root adventures, and remember: those who root together stay together.



Leeks are root vegetables that look quite similar to onions, to which they are related. Their flavor is onion-like but much milder. Unlike onions, leeks don’t form much of a bulb on the end of the root. Instead, they remain cylindrical, with perhaps a slight bulge at the end. The leek is a vegetable that belongs, along with onion and garlic, to the genus Allium, currently placed in family Amaryllidaceae, subfamily Allioideae. Historically many scientific names were used for leeks, which are now treated as cultivars of Allium ampeloprasum.

Types and Varieties

Belton Lancelot
King Richard (open pollinated) Lexton
Lincoln (open pollinated) Megaton
Surfer Tadorna

Soil Fertility

See the Soil Fertility sections for Onions (page 224).


For best results, leek seeds should be sown in the greenhouse about 2.5 months before field setting. About 2-3 lb of seed are needed to raise enough plants to set an acre at average spacing (0.25-0.5 oz per 100 feet of row). Plant seeds no more than ½” deep in 288 deep cell trays. Before setting, clip plants to a height of 3″ to reduce wind damage in the field. Set plants in the field from late April to late May depending on location and earliness desired. Plants can be set in early July for a late fall harvest, or in milder locations, growers may wish to try overwintering the more cold tolerant leek varieties using straw mulch or row covers. Rows can be from 15″-30″ apart depending on equipment; plants should be about 3″-6″ apart (200-400 plants per 100 feet of row).

Field Culture

To develop a long, white stem, leeks can be planted in a trench 3″-4″ deep. The trenches are gradually filled as the leeks grow and then soil is hilled around stems to a height of 3″-4″. Several hillings may be required per season. Self-blanching varieties are grown without trenching and hilling and require less cleaning.

Harvest and Storage

Leeks can be harvested once the base reaches at least 1″ diameter. Soil often clings to freshly harvested leeks. Carefully using a pressure washer or hose nozzle with a strong jet of water may be required to sufficiently clean soil particles from leeks for storage or market. Optimum storage conditions are 32º F with 95%-100% relative humidity to prevent wilting. Leeks typically maintain quality in storage for two to three weeks. Under ideal conditions, up to eight weeks is possible. Store separately from ethylene-producing crops.

The pros and cons of root vegetables

They’re packed with nutrients but high in starchy carbohydrates.

Published: August, 2018

Image: © rudisill/Getty Images

Root vegetables — like turnips, rutabagas, and parsnips — may not be the sexiest foods on the table. But they’re big celebrities in a number of cuisine trends like the “vegetable forward” movement (which elevates vegetables into creative entrees and side dishes) and root-to-stem cooking (which uses every part of a vegetable, including the tops, stems, and skins).

While it’s fun to use old standbys in more interesting ways (like roasted parsnips with pistachio and lemon), it’s important to eat root vegetables judiciously. “They are so high in carbohydrates that they are more like grains than greens. It makes more sense to put them in the same category as breads, rice, or pasta,” says dietitian Teresa Fung, adjunct professor in the nutrition department at the Harvard T.H. Chan School of Public Health.

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This is not as straight forward as it seems, because there are some plants that don’t get on with onions. Depending which type of onions you grow will determine how late in the season you have this problem. Over wintering onions are lifted earlier than spring sown, so what to plant after onions depends on many factors.

What to Plant After Onions

As I said earlier, time is the main problem here, and this is where forward planning is needed. If you have some winter squash, Pumpkin, Swede, Winter Cabbage, Chilli or Tomato plants in pots, these can be planted after onions. Your climate will determine how long you have left in your growing season and that will affect your choice of plants.

Over wintering Lettuce and Radishes can also be grown after onions along with members of the brassica family (if time allows). Late carrots will benefit from the strong aroma left in the soil from the onions. This will confuse the carrot root fly and stop them from laying their eggs.

What Not to Plant After Onions

Never plant legumes which includes all beans and peas, in the same soil that onions have just been lifted from. Onions contain certain compounds that inhibit legume growth, and this will remain in the soil on broken roots etc… Asparagus is another plant that does not get on with onions so should never be planted together or in succession.

The most obvious plant not to grow after onions is… Onions. This is because of the build up of pathogens and pests in the soil and this is why we rotate crops. I use a 4 crop rotation plan ensuring that my soil is fresh for every crop.

Companion Planting Onions

From a companion plant perspective, onions and all of their relatives in the allium family, are helpful to many plants. Plants like:-

  • Strawberries
  • Rhubarb
  • Peppers
  • Carrots
  • Apple trees
  • Apricots

So if you are short on space you can grow your onions alongside, or below any of the above list.

The Benefits of companion planting Onions

I briefly touched on this above and I cannot stress enough just how beneficial the aroma of onions is as a companion plant. This pungent smell will repel and confuse many insects including:-

  • Aphids (greenfly, black fly etc…)
  • Carrot Root Fly
  • Flea Beetles
  • Japanese Beetles
  • Cabbage White Butterflies
  • Tomato Moth
  • Corn Moth

You can benefit from this by growing onions with plants affected by these pests and by growing plants in the same soil after the onions are lifted. This works best with onions grown from sets and not seed. Onions grown from seed are not as pungent.

What To Grow After Onions

In conclusion, there are many plants that will do well in the same soil that onions have been lifted from. As long as they have time to grow and in most cases that means having them in pots and ready to go. The exceptions being Legumes, Asparagus, and more Onions.

Crop Rotation

Crop rotation – despite what my non-gardening mates believe, is NOT the twisting of sunflowers to chase the sun (although, they do have a point… they are crops, and they are rotating!). Crop rotation is in fact a method of managing plantings, both on a small (vegie patch) and large (farm) scale to minimise the risk of pests and diseases, and maximise the yield and productivity of crops. Yup, it all sounds terribly technical, but I promise you it’s not! Hey, if I can manage it, I reckon just about anyone can!

What’s the Deal?

The definition of crop rotation I like the most is ‘The successive planting of different crops on the same land to maximise soil fertility and help control pests and diseases.’ Okay, it sounds very agricultural, but, in essence, this is the principle that we, as home gardeners, can apply to our vegie patches. And let me tell you, it works. The top notch vegies that we grow in our yummy yards, almost always, remove many and various nutrients from the soil during their growing periods. That said, a number of them replace nutrients as well (think beans, peas and other legumes). By varying what we pop in the patch, and what type of crop follows another, we can ensure that our vegies get what they need from the soil… and we get what we need from our vegies!

The other benefit of rotating our crops is that the process helps to interrupt the cycle of host specific pests and diseases. This means that harmful pests and diseases are unable to build up to damaging levels either in the soil or on the host plants themselves. Crop rotation has ‘moved’ their favourite host plants from the area, perhaps whilst the pests were ‘resting’ over winter, and essentially they are now unable to breed or, if they do breed, they no longer have a food source for their young to thrive. Hence the cycle is broken! Hurrah!! Crop rotation is a common practice in many large scale agricultural endeavours, such as in the rice paddies in Southern China. Over a two year cycle, a rice crop is generally followed by an “upland”, non-related crop (such as sugar cane) to help break the cycle and infestation of rice borer. And it must work, cause these guys have been doing it for a long, long time! In fact, crop rotation is reportedly one of the oldest cultural practices that is still kicking around….early civilisations in Africa and Asia used it, as did the Romans.

So how do you do it?

Everyone and their gardening book has a different method for successful crop rotation. After much discussion in the SGA trenches, we have come up with a system we like a lot. It’s simple, easy to manage, and it works!

Our system works on a four bed rotation, meaning there are four separate planting areas. Don’t fret if your garden doesn’t seem big enough to cope with all these beds. You can instead have just one bed and rotate the produce each season. It may mean you can’t grow tomatoes every summer, but you’ll have fun with a lot of other vegies in between! Vegies you can trade for tomatoes at your local vegie swap. If your garden is large enough, use what space you have available, and divide this up into four separate “zones”. Or, if you are starting from scratch, consider a mandala circle style vegie garden. While they look amazing, they will also maximise space, and allow for the zoning of planting areas (which in turn makes crop rotation even easier!). You can even have a spot for the chooks!

The letters correspond to the following vegetables: A: Peas and beans B: Broccoli, Brussels sprouts, cabbage, lettuce and spinach C: Beets, carrots, leeks, onions and turnips D: Cucumbers, eggplant, tomatoes, peppers

Perhaps you’ve seen it driving through the state- a large field that was once soybeans is now corn, the next year, wheat. But is crop rotation really that important for your home garden?

Yes! The rotation of your crops around your garden in a systematic order will make sure you aren’t planting the same crop in the same bed year after year. This helps maintain healthy soil and prevents depletion of nutrients. Each plant requires different nutritional needs, and your crops will affect the soil in a particular way. Rotating your plants takes advantage of abundant nutrients left over from certain crops and allows the soil to recover nutrients that were depleted during the past growing season. Plus, it interrupts cycles of disease and decreases insect infestation.

Becoming aware of the vegetable families will help ease the confusion of rotating your garden. In general, vegetables do well when planted next to others in the same family. Below are common vegetables and the families to which they belong. The similarities between the plants in each family are quite distinct.

Alliaceae (Onion Family)
Chive, garlic, leek, onion and shallot
Amaranthaceae (Amaranth Family)
Beet, spinach, and Swiss chard
Apiaceae (Carrot Clan)
Carrot, celery, dill, fennel, parsley and parsnip
Asteraceae (Daisy Family)
Artichoke, lettuce and sunflower
Brassicaceae (Mustard Family)
Broccoli, Brussels sprouts, cabbage, cauliflower, collard greens, kohlrabi, radish, turnips
Cucurbitaceae (Gourd Family)
Cucumber, gourd, melons, luffa, pumpkin, summer and winter squash, including zucchini
Fabaceae- Leguminosae (Pea Family)
Alfalfa, broad bean, lima bean, peas, snap beans and soybeans.
Poaceae (Grass Family)
Solanaceae (Nightshade Family)
Eggplant, pepper, potato, tomatillo and tomato

Some vegetables do particularly well when planted in succession or after other plants in the same soil. For example, beans and legumes leave soil rich in nitrogen. Nitrogen promotes leaf development, so leafy crops like lettuce and cabbage should be planted in the same bed after beans On the other hand, crops in the Gourd or Nightshade family, such as tomatoes and cucumbers, should not be planted after beans, because the nitrogen in the soil will produce leafy plants with less fruit. Thin-leafed crops, such as carrots and leeks, grow well when planted after leafy plants because there will be fewer weeds in the soil. Tomatoes enjoy the deeper soil left from carrots and beets, and cucumbers will provide weed suppression following a year of thin-leafed crops.

As you plan your garden for the upcoming growing season, take note of the crops you intend to plant and group them by family. Sketch your garden plot and divide it into the appropriate number of beds per family. Label each bed with the family of crops you intend to plant. Keep this layout in a garden journal for the following year. It will be easier to refer to this guide than recall your garden layout by memory. Next year, re-sketch your garden layout and beds. Rotate the vegetable families among the beds, moving in the same direction year after year.

The chart (see images) is an example of a four-bed, counter-clockwise rotation system using common vegetables.

The letters correspond to the following vegetables:

A: Peas and beans
B: Broccoli, Brussels sprouts, cabbage, lettuce and spinach
C: Beets, carrots, leeks, onions and turnips
D: Cucumbers, eggplant, tomatoes, peppers

For home gardens, crop rotation can seem complicated; you are often growing a large variety of crops in a smaller garden plot. But, if you plan ahead and keep a record of your garden layout, crop rotation will be easy and beneficial and you’ll soon notice a healthier and more fruitful garden.

Barbara Arnold is green corps coordinator at Franklin Park Conservatory.

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