The native member of the tea family most easily grown is silky camellia, Stewartia malacodendron.
Of all the native woody plants it has the largest flower of any with the exception of the magnolias.
Like evergreen camellias, the petals are fused at the base and drop as a unit. The white blooms with ruffled edges contrast with dark filaments to make it showy.
Given a site with a half day of sun, the number of flowers can be many. Flowering time is mid May and continues for 3 weeks. Sometimes plants originating from the deep south may flower a few days earlier.
In nature this species is southern with a few plants found in one small area in eastern Texas, then occurring in the southern states which border the ocean, including northwards to southeastern Virginia.
Silky camellia flower buds are round, conspicuous, and showy.
Side view of a silky camellia flower.
Soil Conditions and Fertilization (or not)
This plant has the reputation of being hard to grow. By thinking about the requirement of a soil that is loose and contains organic material (humus) one is on the right track for growing it. To achieve this ideal site it is recommended that rotting leaves be worked into the soil while avoiding black walnut leaves. It is not recommended to plant within 40 feet of a black walnut tree.
Slightly acidic soil is needed with a pH as low as 5.5 being fine.
Feeding the site with leaves annually provides the only nutrition needed. Native Stewartias do not require fertilizer and are easily killed by application of fertilizer.
An easy way to obtain humic acid is a seaweed product sold by Johnny's Selected Seeds. It is called SeaCom and is concentrated - a quart a year will grow all the Stewartias you care to grow. When it is diluted to the color of iced tea, it is sufficient to give young plants a boost. It is possible to make your own compost tea which can be diluted and used for watering. This can be well composted manure or even alfalfa pellets purchased from a store selling animal feed.
If the plants turn a pale green, a little chelated iron or iron in some form takes care of that. Either granular Ironite or a diluted liquid iron product will change leaf color from yellowish or very light green to a darker green. Two light applications a year should be sufficient.
Where to Plant Silky Camellia
It is found in sites that drain well to prevent root rot, have organic material in the soil, and avoid the hottest sun. This means the plants tend to be along creeks, in depressions in the landscape, or little ravines. Along creeks that flood often leaves become layered with sandy soil.
The upper edge of the flood zone is the place to find the plants or in the historical flood zone which may be several feet from the current creek edge. The presence of standing water limits where plants grow. This limitation is noticed in low land closer to coastal areas.
Providing shade to roots of young plants should be considered. Generous applications of rotting leaves helps. Siting the plant on a slope facing north or east keeps roots a bit cooler. This slope aspect may work fine even if only a foot or more. Growing in a flat area works so long as there is no standing water after heavy rains.
Placing Stewartias near other shrubs or small trees which provide afternoon shade helps. In a continuous forest setting with a lot of shade, the plants may be suppressed in size and have few blooms. In nature it tends to be a canopy gap species.
A half day of sun, with protection from noon and afternoon sun, helps silky camellia flower more.
How to Water Silky Camellia
When establishing young plants hand watering is suggested to know how much water is being applied.
Since root rot is an issue with the species, it never wants to stay soaking wet. If compost is worked into the soil, even in hot weather sips of water may be sufficient. For example, a plant 8 inches tall can be watered thoroughly when planted, then maybe two cups of water a week will be enough.
If temperatures are very hot, then shorter watering intervals help. This season plants in the 8 inch tall range survived with watering twice a week in the hot weather.
If dry conditions are likely to persist, a top dressing of composted mulch an inch thick will help the plants along with watering. If the ground appears to be rapidly absorbing water with no pooling, then a gallon or more per watering will be needed. This can happen if the soil cracks or becomes very dry. In this case every other day watering will be needed.
Watering when conditions are hot may not generate new growth until cooling late in the season occurs. This late growth may be six weeks before frost but is never an issue. The plants tend to harden sufficiently and are not harmed.
Size and Growth Rate
A recommendation is to be patient and wait until the time when vigorous growth happens. The little plant may go from growing 3 inches in a year to growing 2 feet in one season.
Plants bloom when about 3 or 4 feet tall.
This silky camellia is growing in Jack's garden in zone 7a.
Pruning, Fall Color, and Propagation
Pruning is never advised unless it is to remove a bit of limb that is in the way of a path.
Allowing all basal stems to grow is necessary since this is the way a plant renews itself. In time the oldest stem will likely become less vigorous and can be removed. An indication that a stem is becoming less vigorous is development of purple fall color.
Of all the native plants this is the one that can have typical fall color of yellow to orange and yet have a stem with leaves edged in purple or even entire leaves purple. This can be seen on some old plants.
When friends admire your spectacular shrub and want it, layering is easy so long as a low limb can be pressed into the ground with a stone or brick. It takes a year for good root formation. Lifting the layers in late winter or early spring as buds swell is the best time to transplant.
Reproduction from seeds can be one year if fresh seeds are immediately planted, two years is typical with more seeds germinating the third year, and sometimes seedlings up to five years later. If space allows install several plants for the floral display and better seed production.
Jack Johnston grows Stewartias to study variations in them, to have a reliable source for seeds, and to enjoy the process. He lives in the Blue Ridge Mountains of NE Georgia where the native species of Stewartia grow well. To date two triploid individuals of the mountain Stewartia (Stewartia ovata) have been located. They have larger flowers and are sterile. Variations in silky camellias including pink streaks or blotches on the petals are being selected. He enjoys encouraging others to grow Stewartia.
Jack has been Cutting Edge Plant's Stewartia patron and has gotten us going with Stewartia malacodenron production. We hope to have 1 gallon plants available in fall of 2021, thanks to Jack. Pictures were taken by Hillary, in Jack's garden.
Here he is standing in a patch of cinnamon fern, instructing us on the ways of Stewartias (pictured with Mike). This is a low spot and not suitable Stewartia habitat.