Ginkgo

( GIN - koh )

At-A-Glance Information

Commonly called Maidenhair Tree, this genus of deciduous trees needs full sun and moderate to regular water. These trees are native to China, and are attractive year-round, especially in fall when foliage turns golden-yellow. Leaves are fan-shaped, resembling Maidenhair Ferns. They are great street and lawn trees, and are long-lived. Plant male trees instead of female trees where possible; female trees are messy and fruit produces a rancid smell. Take care when planting Ginkgo in the landscape, as some plant parts (namely the seeds) are toxic if ingested.

ginkgo Species and Varietals

Ginkgo is the type genus of the plant family Ginkgoaceae and includes just one extant species. Maidenhair Trees grow best in USDA hardiness zones 3-9 or Sunset growing zones A3, 1-10, 12, and 14-24. To find your zone, click here: Zone Map.

Ginkgo biloba (Maidenhair Tree, Fossil Tree, Ginkgo)
This species of Ginkgo can reach 70-100 feet tall, but in gardens commonly tops out around 30-35 feet. Fall foliage color is striking golden yellow. There are many varieties and cultivars of this species with varying characteristics, listed and described below:

'Autumn Gold'
Upright growth to about 45 feet tall and eventually 35 feet wide.

'Golden Colonnade'
Narrow habit, up to 45 feet tall and 25 feet wide.

'Presidential Gold'
Broad, oval tree reaching 50 feet tall and 40 feet wide.

'Princeton Sentry'
Upright, pyramidal and narrow tree reaching 50 feet tall and 15-20 feet wide.

'Saratoga'
Upright growth with a central trunk that reaches to the top of the tree; 45 feet tall and 35 feet wide.

Caring for ginkgo

Take care when planting Ginkgo in the landscape, as some plant parts (namely the seeds) are toxic if ingested. Ginkgo trees thrive in full sun; they will need 4-6 hours of direct sunlight each day at the minimum. They can benefit in some cases from light shade in the afternoon, especially when grown in hotter climates. Trees appreciate loose, well-draining soil that is slightly acidic to alkaline (with a pH of between 5.0 and 7.5). Do not plant Ginkgo trees in areas of the landscape that are depressed or that have poor drainage, as these trees do not like to have wet feet. After installation, apply a thick layer of mulch around the base of the tree to increase soil moisture retention, suppress weed growth, and regulate soil temperatures. Water newly planted trees regularly until they reach a height of 20 feet, and then lessen irrigations to occasional deep waterings. Once established, these trees are drought-tolerant, and can handle dry conditions though they will have more abundant and vibrant foliage if provided with occasional deep waterings. Avoid overwatering and shallow watering (especially if trees are grown in lawn areas).

These trees are not heavy feeders, and will benefit from a simple application of organic compost once a year in springtime. If trees seem to be struggling, however, they may need a feeding with a slow-release, balanced fertilizer in early springtime just before new growth pushes out for the year. Prune any awkward branches on young trees back, as well as any parallel shoots, choosing one main 'leader' shoot to grow. Older trees need minimal pruning; simply remove dead or dying branches. These trees grow slowly, reaching their full size in 30 years or so. Ginkgo trees are very long-lived in their native landscapes, surviving for thousands of years (hence the common name Fossil Tree). In garden cultivation, they have a life span of between 30 and 50 years.

Propagation

Ginkgo can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your tree, follow the instructions below:

Propagating Ginkgo by Cutting

Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. A good substrate for propagation of cuttings is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
In spring or early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about six to eight weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new shrub.

Propagating Ginkgo by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. The seeds on Ginkgo plants are pretty easy to find once you've located a female tree; they are round and typically yellow-green to orangey when ripe. Harvest as many as you can, and place the them in a dry, cool, dark area. Once you are ready, remove them from the bag, cut off the skin, and remove the seeds inside.
Ginkgo seeds have a hard coating that protects them, but this coating also makes it a little difficult to get them to germinate. We can help the process along by scarifying them with sandpaper (or simply rubbing them against an abrasive surface). Do this with as many seeds as you can; they will probably not all sow, and the ones that do will be of varying characteristics. The more seeds you plant, the more chances you will have to get the resulting shrub you want. Place your seeds in warm water and leave for 24 hours. Viable seeds will sink to the bottom, and non-viable seeds will float to the top. You can discard any seeds that float.
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 30-60 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Ginkgo fruits are only produced by female trees, and have an unpleasant smell. Female trees are not commonly planted due to the potent aroma (said to smell like rancid butter or vomit).