Bigtree is the giant drought resistant redwood with a world record for the largest trunk circumference. Though often confused, the narrow coastal species is taller, thinner, more pointed and darker green than this one. Bigtree is found in just a small area on middle elevation west slope of the Sierra Nevada Mountains. The region experiences snow in winter and long dry summers. In the wild as in gardens, this tree demands absolute drainage.
The prickly foliage of the bigtree is bushier than the coast redwood, plus it bears a silvery color with bronze or purple accents to the new growth. It is cold hardy and well suited to mountain landscaping throughout the inland West, particularly in the Rockies. Slow growth but enormous eventual size makes this tree unsuitable for small or average homesites. It is best reserved for rural properties, open space and parks where they can spread and exhibit their natural rounded form. They make stellar choices for estate gardens where their majestic size and unique coloring can be contrasted against deep green conifers for winter interest.
Information source: www.Learn2grow.com.
Genus - Sequoiadendron
Species - Giganteum
Common name - Giant Sequoia
Germination rate - 20%
Pre-Treatment - Required
Plant type - Tree
Vegetation type - Evergreen
Hardiness zones - 6 - 8
Exposure - Full Sun, Partial Sun
Height - 80'-260' / 24 - 80 m
Spread - 22'-30' / 6 - 9 m
Growth rate - Medium
Leaf / Flower color - Green / --
Soil PH - Acidic, Neutral
Soil type - Clay, laom, Sand, well drained
Water requirements - Drought tolerant, average water
Landscape uses - Shade Trees, Street Trees
To start with the seeds should first be soaked for 24 hours in clean water. Once the water has been drained off you need to cold stratify your seeds in the fridge for one month at around +4C. The soaked seeds need to be put in or on some type of non-soil growing medium such as a damp paper towel, rockwool or sterile sand or vermiculite.
After placing seeds in/on the moist substrate, put them into a resealable plastic bag. Place the bag of seeds into the fridge and check them regularly to make sure the substrate remains damp but not saturated. After 4 weeks, the seeds should be ready to sow and will need to be placed at around room temperature +21C (70F) for germination.
You can choose to germinate the seeds in the bag and then transplant them into compost or you can plant them onto compost and wait for seedlings to appear. If you are using the second option, bury your seeds at just 5 mm (1/4") deep. Cover the seed with a thin layer of vermiculite instead of soil. Do not bury them deeper than this as burying them too deep can ruin your chances of success. The advantage of germinating them before moving them to soil is that the compost can hold more fungal and bacterial agents than your starting substrate.
Redwood seeds require a mineral-rich soil with good drainage. It is especially important that the seedlings do not get too wet as this makes them liable to damping off and other fungal diseases. Do not water too much or too frequently. Allow the soil to dry out only a little between each watering.
Redwood seedlings will die very easily if the compost they are in dries out even once. Expose them to increasing light levels gradually. The seedlings also do not grow well in hot, humid conditions. In the early summer, gradually harden off the seedlings and place them outside in a semi-shaded position. Grow them in a container for at least 2 years before planting them in a permanent position.