Q.What Is The Likely Cause Of 16 Yr Old Camellias Becoming Thin And Scraggly/not Producing Many Blooms? In Low Sunlight Conditions.
Two 16 year old Camellias, annual bloomers are located at the brick foundation below a brick/concrete long front porch. For years, they were healthy and in the early autumn, many buds appeared. Depending on the warmth of the autumn season, in extreme SE Virginia, the buds produced blooms, beginning as early as mid December (showy at Christmas). The average time for the blooms to appear is February 14, into the next year – during a mild winter. A few years, the blooms have appeared as late as early April. The trees/tall shrubs are annual/not semi-annual bloomers. The Camellias have a northwestern exposure – and receive direct sunlight only in the PM, from April through August and indirect sunlight September through March. We feel that lack of sunlight year around could be a factor. Could the age of the trees affect their declining health ? Could the location, being near a concrete/brick foundation in a bark-mulch shrub bed, which can hold moisture, during rainy periods cause root rot (have not checked for root rot ? Other shrubs in this shrub bed are Carissa Hollies, Nelly Stevens Hollies (which are thinner in this area) compared to the same tall Hollies on sides of our house, with exposure to more direct sunlight. A couple of Azaleas and a lot of Liriope – succulent grassy plants- not in close contact with the Camellias are present in this bed. Both the Carissa Hollies and the Liriope — plants with lavender summer blooms– are very healthy. Should these two scraggly Camellias be replaced — or is there any helpful remedies for their failing condition ?
Certified GKH Gardening Expert
The soil composition may have changed over the years. Camellias need acidic soil, so consider a pH test and adjust accordingly. They need fertilizer for acid-loving plants scattered under the shrubs following bloom each year. They also need consistent water. It is possible, too, that there is too much competition for nutrients/water with the other plants in the bed, so the yearly fertilizer is important. They also may be getting too much direct sun in the summer. Camellias prefer a shady area with dappled sun. Also check the leaves for evidence of insect pests or disease.
Examine all these points and make needed adjustments. If you don't see improvement within a year, consider replacing them. These articles describe the cultural needs of a camellia.
It could be caused by a series/combination of environmental factors.
Like rhododendrons, azaleas and hydrangeas, camellia japonicas like yours prefer to get dappled sun or morning sun only. Avoid hot afternoon or hot evening summer sun as, in some locations (think: summer in Texas), the foliage could sunburn and fall when exposed to too much sunlight in the summer. The soil should be (1) acidic and well draining or (2) amended if alkaline. For example, camellias here in Texas tolerate my alkaline soil (soil pH 76: I amend in spring and summer to lower the soil ph closer to neutral) but japonicas lose foliage if exposed to my sun from 11am/12pm and on in the summer. Camellia roots are near the top of the soil, like with azalea roots and hydrangea roots; their root system is typically about 4” deep only, shallow, tiny and fibrous. The soil for plants like that should be mulched well at all times of the year (3-4” past the drip line) so soil moisture does not easily evaporate and so the soil is maintained as moist –but not wet- as possible. Inconsistent watering (the soil dries out in the top 4” for a while, then the soil gets watered; then the soil is allowed to dry out again for a while) may cause loss of foliage. Maintaining the soil wet can also cause the plant difficulty getting oxygen and parts could die. The age of the plants is usually not a problem. Camellias are incredibly long lived plants that easily outlive any of us provided that their needs are met. There are specimens out there that were planted more than 400 years ago. Watering Hints -
When to water: Test a few spots around the plant. Water the plant when a finger inserted into the soil to a depth of 4” feels dry.
How much to water: Try to water such that the soil feels moist at a depth of 8” sometime after watering. To test, water when the finger method suggests that the soil is dry; water as usual; wait a while for the water to percolate; insert a finger into several spots around the plant to a depth of 8”. If the soil feels dry at that depth, you may have missed a spot, the soil drains too slowly or you did not use enough water.
Overwatering: to test if your soil is too soggy/wet, insert two fingers into the soil to a depth of 4” and extract some soil in between the two fingers; press on the soil and observe if you see water droplets forming. If you see water droplets, the soil is soggy/wet for some reason (it rained too much recently; the water is not draining fast enough; watering too much; etc.)