GINKGO (Ginkgo biloba)
GENERAL INTRODUCTION
The ginkgo is one of the planet’s oldest and longest-lived trees. The species is a living fossil, largely unchanged for some 300 million years ago. A highly unusual tree with uniquely fan-shaped leaves, it can get very tall (20 to 35 m or more), but it grows extremely slowly: some trees are believed to be more than 1,000 years old.
Ginkgo biloba originated in China, where it has been used in traditional medicine for thousands of years, but is now grown in many places around the world.
GINKGO’S HEALTH BENEFITS
Ginkgo is a “brain herb” that improves memory and age-related mental decline. It improves blood flow to the far corners of the brain, mainly due to its anticoagulant effects. It also encourages release of a powerful natural chemical called nitric oxide that helps to open up the blood vessels of the brain for better circulation and better cognitive function.
Some of the nutrients in ginkgo leaves are powerful antioxidants, including the terpenes and proanthocyanidins. These compounds protect brain nerve cells, allowing them to communicate better and improving cognition and alertness. It may also increase synthesis of an important memory chemical called acetylcholine.
Ginkgo also helps with problems related to the eye. Macular degeneration and diabetic retinopathy—diseases that severely impede sight—are related to decreased circulation to the optic nerve, as well as inflammation and blockage of the tiny blood vessels in the eye. By opening up these blood vessels and decreasing the stickiness of blood platelets, ginkgo helps feed the optic nerve with blood nutrients and oxygen.
The circulatory benefits are not limited to the eyes. Ginkgo also helps improve blood flow to the extremities and improves peripheral vascular disease, which afflicts those with diabetes, Raynaud’s, and Buerger’s disease. And if that wasn’t enough, it may also help circulation to the genital region to aid in erectile dysfunction.
GROWING GINKGO
Difficulty: Easy
Hardiness: Perennial in zones 3 to 9
Time to Plant: Early spring or early fall
Time to Harvest: Late spring to early summer
Location: Full sun
Soil Type: Well-drained: will not tolerate wet soils
The ginkgo—or maidenhair tree—is a slow-growing shade tree that has survived ice ages, wars and even the pollution of cities. Some are hundreds of years old, and the oldest ginkgo fossils date from a period before flowering plants even existed! If you are looking for instant gratification, ginkgo won’t give it to you, but if you desire an attractive specimen offering vibrant yellow fall colour and edible foliage, then this your tree. On the downside, ginkgo is a messy tree that often drops its leaves, so don’t place it close to your deck or pool unless you like to clean.
Gingko trees are either male or female: female trees produce a fruit that smells awful when crushed, so choose male plants for your garden!
Common Varieties: There are many cultivars of Ginkgo biloba offering different mature heights and foliage colour. Varieties include Autumn Gold, Jade Butterflies, Fairmount, and Pendula. Smaller varieties such as Chi-Chi, Troll and Horizontalis are suitable for containers.
Plant
Plant ginkgo in early spring or early fall when frequency of rain is greater, and days are warm but nights are cool. That combination is ideal for root establishment of any shade tree or container grown shrub. Locate in full sun.
Dig a hole twice the depth of the root ball and two-and-a-half times the width. Improve the soil by removing any clay or sand and add loam and manure. Backfill the hole while ensuring the root ball is just above ground level. If your gingko came from the nursery in a container, remove it and score the roots before placing it in the planting hole; with field-dug gingko, just place it into the hole and remove the burlap. Firmly tamp down amended soil around root ball.
Stake your new tree and water it deeply. Then get comfortable and wait!
Remember, soil settles! One of the biggest failures with new trees and shrubs is planting too deep. This increases the chances your plants will drown during the growing season, especially in clay soils. You should plant trees and shrubs above ground level in clay soils. Even in well-drained soils, large plantings like shade trees should be slightly above ground level: root balls will settle in and drop slightly after watering because the soil will compact.
Grow
Gingko is a slow grower—sometimes painfully slow. New plants will take several months to root, and you will not notice growth until the second or third season. But slow and steady wins the race! Gingko is a salt-tolerant, pollution-tolerant tree that will endure pretty much everything you throw at it once it’s established, including periods of drought.
Most garden varieties of gingko won’t grow more than 5 to 8 m, but some mature specimens will reach 12 to 20 m high (40 to 70 feet) by 6 to 12 metres wide (20 to 40 feet). Just don’t expect that kind of growth in your lifetime!
Harvest
Harvest the foliage when the tree has fully “leafed out” in late spring or early summer. The goal is to get tender leaves before they mature: old leaves are tough and may lack potency. Be selective: prune inward-facing or arching branches first, as this will increase air flow and benefit overall tree health. Strip all of the leaves from the branches you just pruned. If you need more leaves, be sure to remove random leaves, never stripping entire branches at one time. Do this midday when it’s cool and dry.
You may be able to enjoy a harvest even if you don’t have a gingko on your property. Gingko often can be found in native forests and are a popular roadside planting—there may even be one on your street.
Store
Gingko leaves can be eaten in salads, made in extracts, or brewed in teas. Wash the leaves when needed. Refrigerate for up to a week in sealed bags, or place on a drying tray in a well-ventilated area out of direct light for up to two weeks. After drying, store in a sealed glass container and use for teas.
PUT GINKGO TO WORK
Drawing blanks? Try this tincture!
The best way to put ginkgo to work is to make an alcohol tincture with it. Its super-easy! Just pick 2 cups of ginkgo leaves, wash them, and place into in a sealable glass jar (like a Mason jar). Pour vodka over them until covered by about an inch. Seal the lid tightly and store in a dark place for 4 weeks, shaking the jar daily. After 4 weeks, strain the mixture, ensuring you press out all the liquid from the ginkgo. Take 1 tsp daily for improved cognitive function and memory. This formula will keep for up to a year.
Bad memory? Don’t forget about this tea!
Simply add 1 cup of boiling water to 5 coarsely chopped leaves of fresh ginkgo. Cover and allow it to steep for 15 minutes. Sweeten to taste. The disadvantage to taking ginkgo in tea form is that the required dosage is much higher: you need at least 3 to 4 cups per day compared to a teaspoon of the tincture.
Mental fatigue? Shoot some brain boosting gel!
If your issue is forgetfulness or lack of mental energy, what are the chances you’ll remember to take the tincture or tea? We’ve got the solution: ginkgo gel shots. You’ll need 7 shot glasses: you’ll take one shot a day, and you can make a week’s worth in advance so they’ll be in plain sight in the fridge and you won’t forget!
Place 7 tbsp (3.5 oz) of ginkgo tincture (as per above) into a small mixing bowl. Add 1 oz (a shot glass full) of Jell-O powder (your choice of flavour) and ½ cup of boiling water. Mix well. Pour evenly into each of the 7 shot glasses and store in the fridge. “Shoot” one per day for optimal memory.
FAST FORWARD
Fast forward to the health food store to purchase Phytopharmica’s Ginkgo Phytosome capsules or equivalent. Follow the instructions on the label.
CAUTIONS
This plant has a powerful anticoagulant effect, and there have been reports of internal bleeding in those who took ginkgo. This is important to note, because there is serious risk of combining it with anticoagulant drugs as well as aspirin, ibuprofen, or any other type of non-steroidal anti-inflammatory drug (NSAID) that has blood-thinning effects.
REFERENCES
Drieu K. Preparation and definition of Ginkgo biloba extract. In: Rokan (Ginkgo biloba): Recent Results in Pharmacology and Clinic. Fünfgeld EW, ed. Berlin: Springer-Verlag, 32–6.
Ferrandini C, Droy-Lefaix MT, Christen Y, eds. Ginkgo biloba Extract (EGb 761) as a Free Radical Scavenger. Paris: Elsevier, 1993.
Lebuisson DA, Leroy L, Rigal G. Treatment of senile macular degeneration with Ginkgo biloba extract. A preliminary double-blind, drug versus placebo study. Presse Med 1986;15:1556–8 [in French].
Lanthony P, Cosson JP. Evolution of color vision in diabetic retinopathy treated by extract of Ginkgo biloba. J Fr Ophthalmol 1988;11:671–4 [in French].
Krieglstein J. Neuroprotective properties of Ginkgo biloba—constituents. Zeitschrift Phytother 1994;15:92–6.
Clostre F. From the body to the cell membranes: the different levels of pharmacological action of Ginkgo biloba extract. In: Rokan (Ginkgo biloba): Recent Results in Pharmacology and Clinic.Fünfgeld EW, ed. Berlin: Springer-Verlag, 1988, 180–98.
Jung F, Mrowietz C, Kiesewetter H, Wenzel E. Effect of Ginkgo biloba on fluidity of blood and peripheral microcirculation in volunteers. Arzneimittelforschung 1990;40:589–93.
Mix JA, Crews WD. An examination of the efficacy of Ginkgo biloba extract EGb761 on the neuropsychologic functioning of cognitively intact older adults. J Altern Complement Med 2000;6:219–29.
Matthews MK Jr. Association of Ginkgo biloba with intracerebral hemorrhage. Neurology 1998;50:1933–4 [letter].
Rosenblatt M, Mindel J. Spontaneous hyphema associated with ingestion of Ginkgo biloba extract. N Engl J Med 1997;336:1108 [letter].