I will be the first to admit that I am lazy gardener. I want my plants to produce a crop of food for my consumption with very little work on my part. I have learned that for a dark green leafy vegetable, tree collards are hard to beat (but note that they are susceptible to the same pests and diseases as other brassicas; however, they do seem to bounce back pretty well each year). Other names for Tree Collards include Tree Kale, Walking Stick Kale, and Purple Tree Collard. Tree Collards are a staple in a permaculture landscape. Tree Collards are a highly productive perennial Brassica, producing delicious blue-green, or purple leaves which taste similar to kale. Like most brassicas, Tree Collards are especially sweet during the cooler months of the year (like now). Although their actual origin is unknown, it is believed that they come from Africa, and have been propagated and passed on within African American communities in this country. I have read that Tree Collards can thrive happily for 10-12 years and then be propagated by cuttings to continue(note, however, that there are other resources which say that Tree Collards need to be propagated 2 years after having been propagated from a cutting). The plants can grow 5-6 feet tall or taller and can sprawl 6-8 feet in all directions. Like many plants, Tree Collards need full sun and rich, moist soil, although I have read that they do acceptably in partial shade.
Tree Collards are difficult to find in nurseries because the profit margin on them is low, as these plants take some time to propagate. These plants are generally passed on from gardener to gardener as cuttings. But if you do not know anyone who owns such a plant, places to purchase Tree Collards locally include specialty permaculture nurseries like the one at Merritt College in Oakland, CA, or the Occidental Arts & Ecology Center in Occidental, CA, when they hold their plants sales (note that this may only be seasonal). Another resource is to order Tree Collards from a permaculture nursery on-line.
- How To Grow Tree Collards
- Richmond’s Purple Tree Collard
- Tree Kale: Kale Grows on Trees
- Collard greens nutrition facts
- Why you should eat your collard greens
How To Grow Tree Collards
John Jeavons is the Executive Director of Ecology Action, a 501(c)(3) organization headquartered in Willits, California. He is known internationally as the author of the best-selling book “How to Grow More Vegetables—and Fruits, Nuts, Berries, Grains and Other Crops Than You Ever Thought Possible On Less Land Than You Can Imagine”, as well as author, co-author or editor of 200 other “how-to” books, booklets, topical papers and DVDs on related topics about food and sustainable soil fertility growing. For the past 44 years Jeavons has devoted his time to research, develop and teach a small-scale, resource conserving agricultural method — GROW BIOINTENSIVE®. His high-yield food raising approach is being successfully practiced in 151 countries in virtually all climates and soils where food is grown, and by organizations such as UNICEF, Save the Children, and the Peace Corps.
You may have heard of it, or seen it at the farmers markets, but if you haven’t we are sure that you soon will came across this amazing plant! Different strains are known as Tree Kale or Walking Stick Kale, Tree Collards (Brassica oleracea var. acephala) are the “tall cousins” in the cabbage family. They grow upwards like a tree, and some plants can reach up to 12 feet tall!
HISTORY AND USE
Tree Collards were introduced to California, probably during the latter half of the eighteenth century, from the island of Jersey in the English Channel where they were grown to feed cattle.
They are super nutritious, very high in calcium, and here at Ecology Action we have been doing practical research on this wonderful veggie since 1982. We found out that a 100-square-foot bed of tree collards can provide 4x more protein and 8x more calcium than the milk produced from a grain feed crops grown in the same area. In addition, tree collards contain no oxalic acid; therefore, they may be eaten raw without iron being tied up.
As perennials, tree collards can thrive for four to five years (and longer), but it is best to rotate them after three years, since they remove so much calcium from the soil. You should consider taking cuttings, planting a new bed, and getting it established, before removing them completely.
They grow well in most temperate climates, although there may be approximately 75% die-back if temperature drops to 18°F and stays there for any length of time. In this kind of environment, take cuttings at least one month before the first hard frost (or use prunings), flat them and keep them in a greenhouse to overwinter; one month after the last hard frost in the spring, transplant the cuttings. A relative of tree collards, sukuma wiki, does well in tropical areas.
Tree Collards along a fence in Willits, CA. Photo: Renata Abbade
Tree collards are most easily propagated from cuttings. They rarely go to seed and when they do, the chances that a cross with another Brassica is good, for example with wild radishes.
To make cuttings you should cut off a healthy, non-woody branch that will provide two or more cuttings. It is possible to get as many as six cuttings from a good-sized branch that has closely spaced nodes. Clean off all but the upper 1 to 2 leaves.
Each initial cutting must have at least six growth nodes. (A growth node is the scar left after a leaf has fallen off or been removed.) A cutting may be as small as 4 to 6 inches long, if the nodes are closely spaced. A 6- to 8-inch cutting is optimal, but more than 12 inches is not desirable. Make sure each cutting has 6 to 8 nodes. This is very important! Once you have grown a mature plant, you will have an abundance of cuttings to share with your gardener friends!
To root each cutting:
Determine the right side up: the more curved part of the node is at the bottom; the place where the new leaves/roots will come out is at the top. Make sure the nodes look more or less like a heart or a smile. It is useful to cut the top of the stems at an angle, as to not retain any water and avoid rotting; and to cut the bottoms flat to help you remember which way to plant it. When you are ready to flat the cuttings, cut off about 1 inch from the bottom of each cutting—make sure you cut just below the next node up from the bottom. This enables water to be picked up more easily from a fresh, clean cut and a good root to develop.
Examples of healthy cuttings. Photo: Renata Abbade
Put the cuttings on 1.5- to 2-inch centers in a 3-inch-deep flat with mounded soil. Make sure at least 3 nodes are under the soil (roots will come from these), and 3 nodes are above the soil (leaves will come from these). Leave the flats in partial shade. For summer cuttings, put the flats in full shade for the first 4 weeks. Keep them evenly moist.
It can take 2 to 4 months for the cuttings to fully root, depending on the time of year. A cutting is ready to transplant when it has 3- to 4-inch-long roots forking from the nodes under the soil or from the bottom of the cutting, and 2 leaves growing from the nodes above the soil.
The best time to transplant is early spring, while the temperature is still mild. If it is too hot, the plants will be stressed and have difficulty more getting established. Each seedling should have one strong stem; remove any others. Avoid starts with multiple stems.
Twelve-inch spacing works best for an optimal edible yield, plus ease of harvest, in a Biointensive bed. On 9-inch centers, the leaves are smaller, and it takes more time to harvest a given amount of leaves. On 15-inch centers, the stems and leaves are bigger, but the yield is good and a cooks dream for easy preparation, yet and it is more difficult to market larger leaves.
Tree Collards on a bright day at Ecology Action’s GROW BIOINTENSIVE®
Research & Education center in Willits, CA. Photo: Renata Abbade
Transplant the cuttings on 12-inch hexagonal centers in a well-prepared bed which has been double-dug and fertilized with compost. Use a hand trowel, 6 to 8 inches long and 2 inches wide, to open a hole deep enough for the roots and place 2 to 4 unrooted nodes under the soil. There should be at least two leaf nodes above the soil. The plant may grow over 9 feet tall, so the cutting needs to be deep enough for the roots already formed to anchor the plant firmly and for other roots to develop from the stem as well. Planting 2 to 4 unrooted nodes beneath the soil will increase the tall plant’s stability later.
To stake tree collards:
Immediately after transplanting, push an 8 foot x 1 inch x 1 inch stake 18 to 24 inches into the soil, about 2 inches away from each plant. This is easiest to do from one row to the next, before the planting board is moved backward. Be careful not to exert too much pressure on the stake, as it can snap, leaving a sharp point. If the bed is on a slope, it is generally better for the stake to be uphill of the seedling.
When all the stakes are in, drape 30% shade netting over the bed at least until the mini-climate is established, i.e., until there are enough leaves for the plant to thrive. Shade netting can be left on during the hot summer to create a healthier environment for the plants. Remove the shade netting in the late summer or early autumn as the weather becomes cooler.
When the plant is about 18 inches tall, use heavy twine to tie a loose figure-eight loop around the stake and the plant, about 12 inches from the ground. As the tree collard gets taller, tie a loop 18 inches above the last loop periodically, so that the plant always has adequate support.
Optimal 12” spacing, and stakes for support every 18”or so. Note that we have inter-planted some nasturtiums with our Tree Collards! Photo: Mike Pearce
Tree collards are best for eating and marketing during the cooler months; here in Willits, CA that means approximately mid-October to June. The sweetest-tasting leaves are the ones harvested after a light frost.
What to harvest:
Harvest the larger leaves that are about 60% green and 40% purple. This will give you higher yields! Also, the green leaves are not as sweet. Always allow at least 5 central reasonable sized leaves to remain at the top of the stalk (6-8 leaves in winter), this will ensure your plant stays alive because there are enough leaves left on the plant to enable photosynthesis. On a stem with a lot of small leaves, remove approximately one-third of the leaves. Leave the bottom purple leaves on the plant to fall off. If they are removed, the next leaf upward will turn purple the next day, thus reducing your yield.
About 60% green is the best time to harvest (leaf on the left). This is when they are the most delicious! Photo: Renata Abbade
How to harvest:
Break off the leaf at the node by snapping it downwards gently but firmly and easily. Do not pull it down slowly—it can peel off part of the stem. The leaves snap off more easily if they are harvested in the morning or evening when it is cool.
During the first year of growth, tree collards may grow 3 to 4 feet tall before winter comes. The following year, they may reach 6 to 10 feet tall.
Ecology Action’s Garden Manager Matt Drewno stands happily next to his 9’ tall Tree Collards at Green Belt Garden in Mendocino, CA. Photo: Matt Drewno
When to prune:
Tree collards should be pruned 2 to 3 weeks before the hottest summer heat—in Willits, that means about the end of July or the beginning of August. This will give the plant enough time to regrow for the winter harvest to begin in November or December.
How to prune:
The goal is for the plant to produce fewer medium to large leaves rather than a lot of smaller leaves, for ease of harvesting and marketing. In our experience, pruning the plants just above a node, to 2 feet high the first year of pruning, 2.5 feet high the second year, and 3 feet high the third year, gives the best yields over time. Even if the first-year plant is not much over 2 feet or even under 2 feet, it is best to prune it back, so that it does not grow too fast and produce too rapid tall weaker growth the second year. Be sure to cut at an angle into green wood, so that the plant will let water flow off the cut easily.
Prune out thin, weak, woody, bent or twisted stems. Leave the 3 to 4 healthiest and strongest stems that are “evenly radial” leaders (more or less evenly spaced around the stem) and remove the others. If there are no strong stems, go back 2 to 3 months later, prune off the smaller shoots, and leave 3 to 4 strong, evenly radial stems. Leave any leaves on the remaining plant stems, but remove any small branches. Be sure the pruned stems are tied securely to their stakes with string in a figure-eight loop.
Loosen the soil carefully with a border fork 3 to 4 inches deep between the tree collards and around the edges of the bed, to aerate the soil and let water in more easily. Be sure not to disturb the plant roots in the process. Water well (approximately 6 min. per 100 sq. ft.).
Cover the bed immediately with shade netting, to protect the pruned plants from excess heat, if necessary, until the new leaf sprouts are about 3 inches long. Water them at midday to help them regrow and keep them cool until the mini-climate is re-established.
One to two months later, prune off any small branches growing below 2 to 2.5 feet. Prune off smaller stems above this level if a lot of small stems shoot out after pruning, but be sure to leave 3 to 4 strong, evenly radial stems.
After pruning, add the stems and leaves to your compost pile and give it a calcium boost! Your other plants and your bones will love you for it!
EATING (The best part about them!)
Tree collards are fun to cook with, and can be used raw or cooked in any recipes that call for kale, collards or cabbage, and are especially good in soup and sauces! They take a bit longer to cook than kale. You can also eat the stems. They are generally twice as sweet as the leaves, and are nutritious as well.
Salad: Finely chopped raw tree collard leaves may be added to salads, but because they tend to be tougher it is nice to massage the leaves with some vinegar or citrus juice.
Sautéed: Stack your tree collard leaves in a pile and roll them together to create a tight bundle – this makes chopping a whole lot easier! In a large skillet sauté some finely sliced garlic and add the tree collards. Cook on high heat for about 3 minutes. You may also want to add some balsamic vinegar or red wine when the pan is very hot to add some flavor!
Steamed: Sauté onion and garlic in large pot. Add chopped tree collard leaves and a small amount of water. Cover pot closely. Stir after about five minutes and continue steaming until tender.
Tree Collard Pancake: Mix together steamed tree collards, mashed potatoes, sautéed onions, and garlic. Form a large pancake or several smaller ones. Brown lightly in hot oil.
Tree collards are also wonderful in tomato sauce or gazpacho, especially if you need an extra nutrition boost! Photo: Renata Abbade
Richmond’s Purple Tree Collard
Richmond’s Purple Tree Collard is one of our favorite plants in the perennial vegetable world! Enjoy delicious and colorful greens all year with this amazing perennial kale that can live up to 20 years. The Richmond’s Purple Tree Collard was selected for its beautiful foliage as well as its particularly sweet leaves which are tastiest in cold weather but can be eaten year round. Even tastier than typical collards and perennial too, tree collards are an essential piece of the perennial vegetable garden. While most brassicas are biennial, flowering in their second year, perennial tree collards continue vegetative growth for many years without flowering. While you may occasionally see a few flower buds on tree collards picking them off will allow the plant to continue in its vegetative stage. Or if you are looking to breed your own perennial kale let it flower! Grow out the seeds and you might find a brand new tree collard! *USDA Hardiness: Zone 8 Latin: Brassica oleracea
Latin Name: Brassica oleracea var.
Site and Soil: Tree Collards like 1/2 day to full sun and well-drained soil.
Hardiness: Hardy to 15° F and perhaps lower once established
Bearing Age: 1 year after planting.
Size at Maturity: 5-10 ft. in height.
Pests & Diseases: White flies & aphids
USDA Zone: 8b
Tree Kale: Kale Grows on Trees
Tree Kale and Garden Kale – the Same but Different
If you want to grow tree kale, forget most of what you know or have heard about growing other types of kale.
While tree kale prefers well-drained soil and full sun to partial shade, like other kales, it tolerates heavy clay soils as well as loamy, sandy ones. It will also grow in acidic soils, although sweetening acidic soils by adding lime does improve growth.
Tree kale also tolerates a wider range of temperatures and climates than other kales, from cool and temperate to humid and tropical. Tree kale is grown along California’s Pacific coast and even in Hawaii. In fact, tree kale reportedly grows better in coastal areas than it does farther inland. In hotter climates, though, both tree kale and garden kale prefer partial shade.
Tree Kale Doesn’t Grow From Seed
Tree kale rarely bolts, flowering and producing seeds. If it does bolt, it does die off like other kales, but unlike other kales, the seeds don’t grow true to the parent plant. They don’t necessarily produce tree kale.
Tree kale is usually grown from stem-tip cuttings that are at least 4 inches to 6 inches long, but, preferably, they should be between 6 inches and 8 inches long. Three to four trees, or a 6 to 8 foot space, can provide a family with enough kale for an entire year, but you will need extra cuttings because not all of them will take root and survive.
To differentiate between the top and bottom of the cutting, cut the end closest to the roots of the plant straight across and make two cuts at the top of the cutting that point upward from the outer edge in toward the center, forming a point. These angular cuts also allows water to run off the top of the cutting which reduces the chances of it rotting.
Include as many growth nodes as possible on each cutting, at least six to eight. The growth nodes are the places where leaves are growing or where they have been removed or fallen off.
The cuttings should be taken from kale trees that are between 18 and 24 months old. Cuttings must be taken before the stems begin to become woody, but cuttings taken when the stems are too young, before they measure between 1/2 inch and 1 inch in diameter, are too thin. Cuttings taken too soon simply wilt and die, while those from woody stems fail to form roots and grow.
To keep the cuttings from losing too much water, remove all but the two or three youngest leaves at the very tip of the cutting.
Winter is the best time to make cuttings.
Planting Your Cutting
If the flat end of the cutting has had a chance to seal itself before planting, help the cutting absorb water by making a fresh cut about 1 inch from the end, just below a growth node.
Plant your cuttings either in the ground or in a one-gallon nursery container, leaving about one fourth of the cutting above the top of the potting soil mix. At least three growth nodes should be below the soil and at least three should be above the soil.
You also can plant cuttings in large coffee cans or yogurt containers as long as you punch plenty of drainage holes in the bottom.
As with regular kale, garden soil is too heavy for container planting, even when you are starting plants for later transplanting.
Whether you plant your cutting in the ground or in a container, choose a partially shaded location in hotter climates, and keep the cutting well-watered, but avoid overwatering that would cause the cutting to rot. The guidelines for growing regular kale is to keep the soil moist at a depth of one inch but to allow the top layer to dry out between each watering.
You can grow tree kale in a container, but if you plan to transplant your cutting, it should have formed a sufficient root system in four to six weeks. You can wait for up to four months to be certain your cutting is ready to be transplanted. As with garden kale, early spring is the best time for transplanting.
Before transplanting, your tree kale should be at least two leaves growing from each node, and the bottom of the cutting or the nodes below the soil should have 3- or 4-inch long roots. When removing the tree kale from the container, be careful not to break the roots off of the plant.
Spacing Tree Kale
For high density planting, you should space your cuttings at least 12 inches apart. If you want taller tree kale with larger leaves, space your cuttings 20 inches apart.
Caring for Tree Kale
Because the main stem produces large leaves as long as it is not pruned or topped, it becomes top heavy. Although the stems eventually become woody, the stems and the root systems are not strong enough to support this top heavy growth without assistance, especially in high winds or wet soil.
Planting tree kale next a wall, fastening it to a wall, or staking it to an 8 to 10 foot high tree stake with 2 to 3 feet of the pole buried in the ground provides the support tree kale needs. One stake should be placed about 2 inches away from each tree kale when it is planted. Use the stakes as support for 30 percent tree netting, especially in the summer or in hot climates, until your tree kale has a sufficient number of leaves to thrive. The netting also protects your kale from the insects that can attack both garden and tree kale. You can remove the netting when the weather begins to cool if not before then.
When your tree kale is about 18 inches high, use heavy twine to make a loose, figure-eight loop around the tree kale and the pole at about 1 foot above the ground. Tie additional figure-eight loops every 18 inches as your tree kale grows.
Topping your tree kale at 8 to 10 feet, or even at any height above 5 feet, encourages it to form branches. Once the main stem is topped, the leaves may become smaller. The leaves on the side branches are always smaller ones.
Pruning Tree Kale
Tree kale can be pruned to slow and strengthen growth, especially when it is spaced for high density harvesting.
The best time for pruning is two to three weeks before summer’s hottest temperatures. This allows your kale time to produce more growth for cool weather harvesting.
To prune tree kale:
- Cut the main stem back by 2 feet the first year, by 2 1/2 feet the second year, and by 3 feet the third year.
- Remove weak, damaged, twisted, woody, bent or thin side stems.
- Leave three to four of the strongest branches evenly spaced around your tree.
- If your tree kale lacks strong side stems, wait two to three months, and then remove the weaker stems.
- Also remove any small stems growing from the side stems.
- Do not remove any of the leaves.
After this first pruning of the year, use a border fork to loosen and aerate the soil 3 to 4 inches deep, and then water it well. If needed, cover your tree kale with shade netting to protect it from the heat until the new leaves are 3 to 4 inches long.
One to two months after this pruning, revisit your tree kale and remove any small stems growing below 2 feet to 2 1/2 feet, unless you want your tree kale to spread. If the tips of these lower branches touch the soil, they can take root and send up new shoots the entire length of the stem.
At this time, you should also remove any smaller stems that have emerged above the 2 to 2 1/2 foot height, leaving your three to four strong stems from the first pruning of the year.
Add the stems you remove to your compost.
Harvesting Tree Kale
When harvesting tree kale, keep in mind that the green leaves are not as sweet as the ones with some purple on them.
When harvesting tree kale:
- From the main stem, pick the larger leaves from the main stem that are about 40 percent purple and 60 percent green. These will be the sweetest.
- Leave at least five leaves at the top of the main stem during the growing season and six to eight over the winter.
- Leave any completely purple leaves at the bottom of the plant. Removing these causes the next leaf above them to turn completely purple.
- You can pick up to one-third of the leaves from the side branches.
To pick the leaves, snap them gently but firmly downward as you would with garden kale. Avoid peeling them down the stem.
Harvesting is easier in the morning or evening when temperatures are cooler.
Serve the leaves in salads, soups, and stews; sauté or lightly roast them; or make them into kale chips as you would the leaves of garden kale. You can, however, do something a little different with the larger tree kale leaves. You can use them as wraps for hearty fillings.
Collard greens nutrition facts
Selection and storage
Although fresh collard greens can be available year around in the markets, they are at their best from November through April. The plant is generally ready for harvesting at 6-8 weeks after seedling. The whole plant is cut about 4 inches above the ground surface and tied in bundles. Usually, new sprouts emerge from the sides which can then be harvested again after a few weeks.
In the stores, look for fresh, bright, crispy leaves with a stout stalk. Avoid those with yellow discolored, sunken leaves. Whenever possible, choose these greens from the nearby organic farm in order to get maximum health benefits.
Once at home, collard greens should be cleaned as the same way as you do in any other greens like spinach. Wash the whole bunch in cold running water for few minutes until the dust, dirt rid off from the leaves and then rinse in salt water for about 30 minutes to kill any germs, cysts, and to rid off any residual pesticides.
Use collards while they are fresh. Collards have relatively good shelf-life and can be stored in the refrigerator for up to four days.
Preparation and serving methods
Both stalks and leaves are edible. Trim away tough stalks and thick leaves using a paring knife. The leaves should be chopped into smaller sections to aid in even and quick cooking. Extensive cooking may result in loss of some amount of vitamins like folates and vitamin-C.
Here are some preparation tips:
Collard greens stirfry. (Photo: by Amy Stephenson)
Collards are one of the favorite greens employed in different traditional recipes in the Southern states.
Collard greens add cabbage flavor note to the salads, cooked meat, and fish dishes.
Its fresh leaves can also be juiced mixing with other complementing greens, fruits and herbs.
Like other members of the Brassica family, collards may contain goitrogens, which may cause swelling of the thyroid gland. Eating raw collards, therefore, should be avoided in individuals with thyroid dysfunction. However, it may be used liberally in a healthy person.
It should be used sparingly with people suffering from oxalate kidney stones.
100 g of raw collard greens carry more than 400 µg of vitamin-K well above daily recommended value; it is, therefore, should be used cautiously in people taking anticoagulants like warfarin.
Medical Disclaimer: The information and reference guides in this website are intended solely for the general information for the reader. It is not to be used to diagnose health problems or for treatment purposes. It is not a substitute for medical care provided by a licensed and qualified health professional. Please consult your health care provider for any advice on medications).
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USDA National Nutrient Database.
Stanford School of Medicine Cancer information Page- Nutrition to Reduce Cancer Risk.
Unversity of Illinois Extension- Watch your gaden grow..
The basics for growing tree collards
The purple tree collard is a vegetable gardener’s dream. With a little attention every now and then a tree collard plant will provide you with delicious, nutritious greens all year round. Here are some basics to get you started.
Perennial member of the brassica family, hardy to around 20° F
The tree collard is a member of the brassica family. It is related to traditional collards, kale, broccoli, cabbage, brussels sprouts and a number of other popular vegetables. However, unlike most of its relatives, purple tree collards are perennial. This means that, like a fruit tree or rose bush, once you plant them they will continue to grow and produce year after year. Traditional collards, kale, etc. must be grown from seed each year and then die after they go to seed. This is one of the top reasons why so many people love tree collards- once you have a plant established you don’t have to plant new seeds every year.
Tree collards are hardy to around 20° F. In fact, they taste best after a frost. If they are exposed to temperatures below 20° for an extended period of time, your plants will die and you will have to start new ones. Thus, tree collards are especially suited to mild climates, such as those on the pacific and southern coasts of the United States. Some people in colder climates still manage to grow tree collards by taking them indoors each year.
New plants are easily started from cuttings
Starting a new tree collard plant is simple. Instead of seed, you will need a cutting from the branch of another tree collard. We have a complete tutorial on how to propagate tree collards from cuttings here. Occasionally tree collards will bloom and set some seed (unlike many other vegetables, tree collards will keep growing and thriving after they have set seed). These seeds can be grown but they won’t make a plant identical to the mother plant. You can certainly grow seeds as an experiment- you may wind up with another new type of leafy green- but the tried and true method of propagating tree collards is via cuttings.
Tree collards can grow upwards of eight feet tall
Take some time considering where to plant your tree collards in your garden. If planted in fertile soil they can grow over eight feet tall! Tree collards are a great way to create privacy in your garden. At the end of our video on planting tree collards there are some examples of staking them and training a collard up an arbor.
Tree collards, like most vegetables, thrive in moist, well aerated soil rich in organic matter. In drought conditions, tree collards respond by producing smaller leaves and growing slower. If you want large plants with a big harvest, you will need to make sure they get supplemental irrigation during dry periods. However, they can live a surprisingly long time with minimal water.
Pruning and Harvest
Tree collards require very little maintenance once established. If they are left to do there own thing though, they will tend to develop long, leggy stalks that are unattractive and less productive. To create bushier, more compact growth, it is important to prune them on occasion. We have a tutorial on pruning and harvesting here.
In Northern California where we grow our tree collards, they are virtually pest and disease free. When our broccoli and kale are getting hit by aphids, the tree collards are often unscathed. Our tree collards are also less affected by slugs and snails. Each year during the summer they do get a bit of powdery mildew on older leaves. We pick these off and compost them or feed them to our poultry. Deer love tree collards, so it is important to plant them in protected areas! Please help us improve this section by sharing your experiences with pest and diseases on our Facebook page.
Why you should eat your collard greens
Share on PinterestCollard greens contain many essential nutrients.
A diet that is rich in fruits and vegetables appears to help reduce the risk of many lifestyle-related health conditions.
A high intake of plant foods, such as collard greens, appears to decrease the risk of a number of health conditions, including obesity and overall mortality, diabetes, and heart disease.
A low intake of vitamin K can increase the risk of osteoporosis and bone fracture.
Vitamin K acts as a modifier of bone matrix proteins, it improves calcium absorption, and it may reduce urinary excretion of calcium.
One cup of boiled collard greens provides 770 micrograms of vitamin K.
The 2015-2020 United States Dietary Guidelines recommend that a woman aged 19 to 30 years should consume 90 mcg a day of vitamin K, and a man of the same age should consume 120 mcg.
One cup of collard greens provides this much vitamin K several times over.
Studies suggest that people who eat plenty of cruciferous vegetables have a lower risk of developing various types of cancer, including cancer of the upper digestive tract, colorectal, breast cancer, and kidney cancer.
Cruciferous vegetables have sulfur-containing compounds known as glucosinolates.
These compounds may help prevent the cancer process at different stages of development for lung, colorectal, breast, and prostate cancers, and possibly melanoma, esophageal cancer, and pancreatic cancer.
In 2017, researchers published the results of a study involving nearly 3,000 people. They were looking for possible links between the incidence breast cancer and the consumption of cruciferous vegetables.
The findings suggested that consuming cruciferous vegetables may lower the risk of breast cancer, especially in women who have not yet reached menopause. They note that cooking methods may make a difference, as cooking some cruciferous vegetables can reduce the levels of glucosinolates.
Whether this is true of collard greens or not was unclear from this study, as most people do not eat collard greens raw.
There is evidence that collard greens and other green vegetables that contain high amounts of chlorophyll can help to block the carcinogenic effects of heterocyclic amines. These substances are generated when grilling foods at a high temperature.
Diabetes and liver function
The 2015-2020 Dietary Guidelines for Americans recommend 22.4 to 28 grams of fiber a day for women, depending on age, and 28 to 33.6 grams a day for men.
Results of a study published in 2014 suggest that a high intake of fiber might reduce inflammation and glucose levels in people with type 1 diabetes.
It may help people with type 2 diabetes to achieve better levels of blood sugar, lipids, and insulin.
One cup of boiled collard greens provides nearly 8 grams of fiber.
Collard greens also contain an antioxidant known as alpha-lipoic acid.
Studies suggest that alpha-lipoic acid (ALA) can lower glucose levels, increase insulin sensitivity, and prevent changes related to oxidative stress in people with diabetes. It can also help to regenerate liver tissue.
Investigators have also observed that ALA may decrease the symptoms of peripheral neuropathy in people with diabetes.
However, it remains unclear whether ALA can be effective as a long-term treatment. In addition, studies have used intravenous ALA. Oral supplementation may not provide the same benefits.
Excessively high doses of ALA appear to produce adverse effects similar to those caused by too little. While “normal” amounts can help prevent oxidative stress, high levels may lead to cell damage.
Researchers have found that consuming collard greens improved liver function in rats with high blood pressure.
Collard greens are high in both fiber and water content. These help to prevent constipation, promote regularity, and maintain a healthy digestive tract.
Healthy skin and hair
Collard greens have a high vitamin A content. Vitamin A is necessary for sebum production, and this keeps hair moisturized.
Vitamin A is crucial for the growth of all bodily tissues, including skin and hair. It also supports the immune system and the eyes and helps keep the body’s organs healthy.
Vitamin C enables the body to build and maintain levels of collagen, which provides structure to skin and hair.
An adult woman needs 75 mg of vitamin C a day, and a man needs 90 mg. A cup of boiled collard greens provides nearly 35 mg of vitamin C.
Iron prevents anemia, a common cause of hair loss. A lack of iron in the diet can affect how efficiently the body uses energy. Collard greens, spinach, lentils, tuna, and eggs are good sources of iron.
Adults need to consume 8 mg of iron a day, and women during their reproductive years need 18 mg. One cup of boiled collard greens provides 2.5 mg of iron.
Sleep and mood
Collard greens contain choline, an important neurotransmitter. Choline helps with mood, sleep, muscle movement, learning, and memory functions.
Choline also helps to maintain the structure of cellular membranes, the transmission of nerve impulses, the absorption of fat, and the reduction of chronic inflammation.
Folate, also present in choline, may help with depression, as it can prevent an excess of homocysteine from forming in the body.
Scientists have found high levels of homocysteine in people with bipolar disorder and depression related to alcohol use disorder.
Consuming folate may help reduce the risk of depressive symptoms in some people.
Why not grow your own collard greens? You can purchase the seeds online.