Sequoiadendron

sequoiadendron

( seh - KWOY - uh - DEN - drun )

At-A-Glance Information

Commonly called Giant Sequoia or Big Tree, this evergreen tree species needs full sun and moderate water to perform well. These plants are among the largest living trees in the world, and in their native habitat can reach 325 feet tall with a trunk 30 feet in diameter. They can live thousands of years, and are closely related to Coast Redwood, but are more hardy. Foliage is scaley, greyish green and somewhat prickly. Lower branches when they touch the ground will sometimes take root and form another tree that blends into the original. Cones are dark reddish brown. In gardens, these trees top out around 60 to 100 feet tall and 30 to 50 feet wide. These large trees are used in large landscapes as specimen trees, tall privacy screening, or grouped in groves.

sequoia Species and Varietals

Sequoiadendron is a genus in the plant family Cupressaceae, and includes just one extant (living) species. The trees in this genus are closely related to those in Sequoia (Coast Redwood) and Metasequoia (Dawn Redwood). The ideal growing zones for Giant Sequoia are USDA hardiness zones 6-9 or Sunset growing zones 1-9 and 14-23. To find your zone, click here: Zone Map.

'Glaucum'
With blue-green foliage.

'Pendulum'
This variety has strongly weeping branches and tops out around 25 feet, but can be kept more compact (around 6 feet wide).

'Barabit's Requiem'
With a weeping habit; reaches 25 feet tall. A bit thicker trunk and a bit wider than 'Pendulum'.

'Bultinck Yellow'
Golden new foliage, slower growing and a little more compact than the species.

'Albospica'
This variety is a variegated, dwarf form that grows at a rate of around 4 inches per year.

Caring for sequoiadendron

These beautiful, fast-growing landscape trees do well in full sun, but they can also tolerate partial shade. For optimal growth and foliage color, make sure that the tree receives between 6 and 8 hours of direct sun each day. These trees can grow to be quite large, so make sure that the chosen planting site has enough space to allow for the full size of the tree. Sequoiadendrons prefer moist but well-draining soil that is slightly acidic to neutral with a pH of between 5.5 and 7.5. They can tolerate a wide variety of soil types, as long as they are well-draining, but do prefer loamy soil. Apply a thick layer of mulch around the base of trees to suppress weed growth, increase soil moisture retention, and help to regulate soil temperatures. Water new plantings regularly as they develop strong root systems. During dry spells, make sure to provide extra deep waterings. Established trees are somewhat drought-tolerant, but do perform best with consistent moisture. Water deeply, especially during long dry periods of the year, and allow soil to dry out somewhat between waterings to discourage fungal root rot issues.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. Prunings should focus on maintaining the tree's natural pyramidal form instead of changing it, and these trees do not need much assistance in doing so on their own. In late winter or early springtime, simply remove dead, broken, or diseased branches. Make sure to hire a certified arborist for large or high-hazard branches. Never top these trees, as it will ruin their natural central leader and permanently disfigure them. Sequoiadendron trees can be expected to survive for thousands of years before needing to be replaced.

Propagation

Sequoiadendron are best propagated using seed harvested in the previous season. To propagate your Giant Sequoia tree, follow the instructions below:

Propagating Sequoiadendron 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. Seeds are contained inside of the female cones. Remove cones from the tree or pick them up off of the ground if they have started to drop already and place them in a paper bag. Gather as many as you can and bring them indoors. Place the bag in a cool, dark, dry area as the cones open up and release seeds. The bag can also be shaken once in a while to speed up the process. Once seeds have been released, take them out of the bag to work with them.
Seeds will need to be cold-stratified; to do so, place them in a plastic bag or other sealable container filled with moistened peat moss or sand. Place the container in the refrigerator and leave it for between four and six weeks' time. Remove the seeds and then take them out to work with them.
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 between 4 and 15 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.